About Underdark:Defense
Defend the Flame from the dark! Level up, strategically place towers, and choose buffs to grow stronger. Keep the light alive! Defend the Eternal Flame: Experience the thrill of defending the flame from hordes of dark...
Defend the Flame from the dark! Level up, strategically place towers, and choose buffs to grow stronger. Keep the light alive! Defend the Eternal Flame: Experience the thrill of defending the flame from hordes of dark forces that besiege it! Feel the exhilaration as you clear stages, with each victory more satisfying than the last. One-Handed Gameplay: Enjoy easy-to-master controls, designed for one-handed play. Perfect for strategic fun anytime, anywhere. Customize Your Defense Strategy: Select buffs and strategically place towers to forge your path of resistance. As you level up and choose your growth buffs, your defense becomes an impenetrable fortress. Heroic Stand: Choose your guardians to stand against the night. Each hero brings unique abilities to the battlefield. Earn trophies, level up, and enhance your heroes to ensure the flame flickers on through the darkest nights!
Version History • October season with Treasure Hunter, Plague Doctor and Agni, refreshed events, stages 981–1000 and the Calcite ranking tier. • Reworked chat with guild chat, whispers, co-op recruitment, translation, blocking and room sharing. • Added SSS support hero effects at level 20 and improved relic tower Attack bonuses. • Expanded equipment filters, safer awakening controls, Send All Gifts and friend request settings. • Added hero and tower suggestions after repeated stage losses. • Improved daily and weekly rankings, combat performance and interface stability. 3.4.1 Sep 30 Updated the App Store screenshots. Game content remains unchanged from the previous version. 3.4.0 Sep 26 ■ New: Item Awakening Awaken God grade equipment up to Awakening 5. · Use items of the same type from Storage as materials — 1, 2, 4, 8 and 16 per stage (31 in total). · Awakening always succeeds, and your item level and bonus options are kept. · The main option grows up to 5× its original value, and each item's unique effect grows stronger at every stage. · An awakened item can only be replaced by one of the same type and grade, and keeps its awakening level. ■ New: Friends · Add up to 30 friends by exact nickname search or from the suggested list. · Send free Diamonds to friends once a day each — the recipient gets 1 to 30 Diamonds. · Gifts can only be claimed on the day they arrive (KST). ■ Friend Roulette Event · Earn 1 roulette ticket every time you claim a diamond gift from a friend. · Spin for Gold, Keys, Diamonds, Embers and more. Spin 10 is supported. · Milestone rewards from 30 up to 300 total spins, including a Legendary Hero, Legendary Tower, God grade item, random Skin and a Unique Mount. · Runs until September 30 (KST). ■ PvP Season 3 — Boss Counterattack Every 5 waves, send one of three bosses to your opponent's side. The chance is shared and does not stack. · Shapeshifter — changes the type of all towers · Destroyer Lord — destroys 4 random towers · Herald of Frenzy — while alive, all monsters move 25% faster New season score rewards and a new season shop are open, and rankings and purchase limits have been reset. ■ Improvements and Bug Fixes · If Co-op Dungeon stops progressing, you are now notified and returned to the lobby. · Chain towers now also link with teammates' towers in Co-op Dungeon. · Co-op room codes now accept codes containing letters and numbers. · Fixed incorrect pricing when buying item boxes in bulk. · Fixed rewards being lost when an error occurred while claiming all mail. · The Medusa map curse now triggers every 2 waves instead of every wave. · Fixed damage numbers not being shown at low FPS. 3.3.11 Sep 14 The September Update is here! - Updated abilities for the featured Heroes, Rabbit and Orc & Boar - Added a new Ranking Tier - Renewed the Season Pass, Growth Missions, and event content - Improved Co-op and PvP battles - Improved combat information displays - Additional bug fixes and stability improvements 3.3.10 Aug 31 3.3.9 Update Notes - PVP Dungeon 2 has been added. - Fixed an issue where clear rewards were not granted when completing another dungeon after playing a PVP Dungeon. - Fixed an issue where the hero joystick did not work in PVP Dungeons. - Improved overall game stability. - Fixed an issue where the Mount Package was not displayed. - Fixed an issue where monsters could not be defeated after Stage 900. 3.3.9 Aug 15 新規イベントを追加しました。 ステージ900以降でモンスターの体力が減少しない問題を修正しました。 乗り物パッケージが正常に表示されない問題を修正しました。 3.3.7 Aug 13 “A Princess and a Knight” Rework - Whenever the Day changes, you can select a weapon for the knight to equip or replace. - Weapons appear in four grades, with each grade having an equal chance to appear. - The weapon selection screen now displays the target hand and its currently equipped weapon. - Skipping a weapon selection now correctly advances the next selection between the left and right hands. [Ability Changes] - Level 3: Whenever the princess or knight defeats an enemy, Final Attack and Critical Damage increase by 5%, stacking up to 2,000%. The current bonus is displayed with a buff icon. - Level 6: Grade 1 and 2 weapons no longer appear; only Grade 3 and 4 weapons appear. Skipping weapon selection grants 1–2 pickaxes. - Level 9: The knight can equip an additional weapon in the right hand, allowing three weapons in total. - Level 12: Each time a weapon is equipped or replaced, the princess and knight gain 20% Attack Speed, stacking up to 500%. The current bonus is displayed with a buff icon. Fixed related issues and improved weapon selection and attack stability. 3.3.6 Aug 1 Version 3.3.5 Update - The August Season has begun! - Featured Hero: Squirrel Thunder - Sub Hero: A Princess and a Knight (Remake) - Improved Squirrel Thunder’s abilities and exclusive buffs. - Adjusted the balance of Orc and Boar and Mysterious Armor. - Normal Stages have been expanded to Stage 970. - Additional bug fixes and stability improvements have been made. Thank you for playing UnderDark: Defense! 3.3.4 Jul 31 This update improves PvP matchmaking and convenience features while addressing several issues. • Improved PvP matchmaking to search a wider score range over time. • The dungeon menu now retains the last selected tab and ranking list position. • Your selected discard rarity is now remembered separately for items, pets, relics, and housing. • Fixed issues with Blink, game speed, mount abilities, and dungeon lists. We will continue improving the game for a more stable experience. 3.3.3 Jul 18 Improved public random matchmaking. If no match is found within 15 seconds, the search will expand to include players from other regions. Improved friend room recovery. If the connection is lost after opening another app, the room will be restored automatically using the same room code. Increased PvP score changes and adjusted how monster HP and movement speed scale over time. Fixed various Co-op and PvP Dungeon issues involving the 10-Ton Weight, Hell Barrel, Chubby Shark’s anchor, Mysterious Cyclopean Portal, and tower information. You can now select how many Hero / Tower Contracts to use when you own 100 or more. Optimized memory usage to reduce crashes during gameplay. 3.3.2 Jul 13 Update Notes - Fixed an issue where rewards might not be granted correctly or the game could become stuck on the results screen when playing normal stages or auto-play-supported content after using PvP mode. - Fixed an issue where acquired items might not appear correctly on the results screen. - Improved overall game stability. 3.3.1 Jul 11 The PvP event is now live! Compete against other players in real-time PvP battles, climb the rankings, and earn score rewards. This update also improves PvP stability, reward display, battle UI, and fixes various gameplay issues. 3.3.0 Jul 11 3.2.9 Update Notice - Fixed multiplayer co-op so equipped heroes, towers, pets, and items now apply their actual levels and bonus options. - Fixed an issue where the loadout shown in the Daily Co-op/Guild Co-op lobby could differ from the actual in-game loadout. - Fixed a text issue where pet drop rate increase effects were shown as item drop rate increases on some screens. We will keep improving the game for a more stable play experience. 3.2.9 Jul 8 - Improved co-op mode stability. - Fixed some display issues. - Fixed other bugs and improved overall stability. 3.2.8 Jul 6 This update includes a major overhaul of the multiplayer co-op experience. We have reworked several co-op systems to improve the overall flow, stability, and long-term foundation of multiplayer play. Because this was a large change, we will continue monitoring reports closely and applying fixes as quickly as possible. We also focused on in-game performance optimization to make battles feel smoother and more stable across more devices. After recent server updates, some players experienced unexpected issues. We sincerely apologize for the inconvenience. We are continuing to review reports and logs carefully to prevent unfair losses and improve the overall service stability. 3.2.7 Jul 4 Version 3.2.6 Update Samurai and Ninja have been improved. Samurai’s [Target the Strong] boss bonus damage now applies as independent bonus damage. The Lv.9 wave-based attack bonus has been increased from 30% to 60%, and Crescent Slash now flies forward and pierces enemies. At Lv.12, Samurai now starts the game with 4 [Target the Strong] cards. Ninja now deals 2x damage to monsters with 20% HP or less. Shuriken hits now apply Shadow Marks, increasing damage taken by marked enemies. The mark limit increases further at Lv.12, allowing much higher bonus damage. Bingo and Board Game events can now run at the same time. You can select and play each event separately from the event screen. Ranking league promotion has also been improved. Promotion steps now vary by rank, and the number of tiers gained is shown when promoted. 3.2.6 Jun 30 Applied recent server/account system fixes. Improved stability. 3.2.5 Jun 28 [Notice] Cloud Save Button Restored Hello, The 'Cloud Save' button that was temporarily disabled has now been fully restored. You can use the Cloud Save feature normally again. We sincerely apologize for any inconvenience and thank you for y 3.2.1 Jun 1 [UnderDark:Defense June Update] - Reaper and Fat Shark heroes are newly revamped. - Reaper’s minion system is improved. - Fat Shark’s iron anchor ability is improved. - Normal stages are expanded up to Stage 940. - The Bingo event begins. - Translation and item box related bugs are fixed. - 1 additional support mercenary ability slot is added. 3.1.9 May 31 [UnderDark: Defense] May Update - Balance improvements will be applied to Alien Spaceship and Joker characters. - Alien Spaceship’s Black Hole and Laser abilities will be enhanced. - Joker’s Card Stack and Surprise Box abilities will be improved. - Auto option settings for items, mounts, pets, and relics will be added. - Hero and tower stat calculation details will be improved. - An issue with the oversized unlock icon in the Silkworm Moth Dungeon will be fixed. 3.1.8 May 21 [UnderDark: Defense] May Update - A new hero, “Alien Spaceship,” has been added. (Equipped with Laser and Black Hole skills) - The Joker hero has been revamped, improving attack mechanics and growth elements. - Normal stages have been expanded up to 930, with new stages added. - Events have been updated. (Board minigame begins / Bingo and Tower Pass end) - Balance adjustments have been made to boomerang-type items. - Some ranking translation errors have been fixed. 3.1.7 Apr 30 - Se corrigió un problema que mostraba el selector de cuentas de Google en cada inicio de sesión. 3.1.6 Apr 19 [Underdark: Defense] April 11 Update - Guild capacity adjusted to 50 to match server limits and fix UI display issue - Fixed an issue where weekly spending ranking currency changed abnormally - Fixed an issue where Goblin Factory Tower was infinitely duplicated due to Imp Hero effect - Fixed an issue where Sun Ring refresh option did not work properly - Fixed an issue where buffs were skipped when refreshing after watching ads 3.1.5 Apr 10 [Underdark: Defense] April 1 Update - Stages are expanded up to 920. - The Season Pass will be updated. - Living Tower growth missions are added. - Living Tower heroes are buffed. - The “Unexpected Companion Chicken” hero is buffed. 3.1.4 Mar 31 [Underdark: Defense] Update - Added 4 new towers - Added new ranking dungeon “Silkworm Moth” - Added new limited tower pass - Reduced difficulty of Co-op Dungeon 1 - Fixed an issue where the Buff Reset +1 option did not stack 3.1.3 Mar 22
Previous Versions
Here you can find the changelog of Underdark:Defense since it was posted on our website on 2026-02-03 23:22:04.
The latest version is 3.4.1 and it was updated on 2026-10-10 11:20:28. See below the changes in each version.
Underdark:Defense version 3.4.1
Updated At: 2026-10-08
Changes: Version History • October season with Treasure Hunter, Plague Doctor and Agni, refreshed events, stages 981–1000 and the Calcite ranking tier.
• Reworked chat with guild chat, whispers, co-op recruitment, translation, blocking and room sharing.
• Added SSS support hero effects at level 20 and improved relic tower Attack bonuses.
• Expanded equipment filters, safer awakening controls, Send All Gifts and friend request settings.
• Added hero and tower suggestions after repeated stage losses.
• Improved daily and weekly rankings, combat performance and interface stability. 3.4.1 Sep 30 Updated the App Store screenshots. Game content remains unchanged from the previous version. 3.4.0 Sep 26 ■ New: Item Awakening
Awaken God grade equipment up to Awakening 5.
· Use items of the same type from Storage as materials — 1, 2, 4, 8 and 16 per stage (31 in total).
· Awakening always succeeds, and your item level and bonus options are kept.
· The main option grows up to 5× its original value, and each item's unique effect grows stronger at every stage.
· An awakened item can only be replaced by one of the same type and grade, and keeps its awakening level.
■ New: Friends
· Add up to 30 friends by exact nickname search or from the suggested list.
· Send free Diamonds to friends once a day each — the recipient gets 1 to 30 Diamonds.
· Gifts can only be claimed on the day they arrive (KST).
■ Friend Roulette Event
· Earn 1 roulette ticket every time you claim a diamond gift from a friend.
· Spin for Gold, Keys, Diamonds, Embers and more. Spin 10 is supported.
· Milestone rewards from 30 up to 300 total spins, including a Legendary Hero, Legendary Tower, God grade item, random Skin and a Unique Mount.
· Runs until September 30 (KST).
■ PvP Season 3 — Boss Counterattack
Every 5 waves, send one of three bosses to your opponent's side. The chance is shared and does not stack.
· Shapeshifter — changes the type of all towers
· Destroyer Lord — destroys 4 random towers
· Herald of Frenzy — while alive, all monsters move 25% faster
New season score rewards and a new season shop are open, and rankings and purchase limits have been reset.
■ Improvements and Bug Fixes
· If Co-op Dungeon stops progressing, you are now notified and returned to the lobby.
· Chain towers now also link with teammates' towers in Co-op Dungeon.
· Co-op room codes now accept codes containing letters and numbers.
· Fixed incorrect pricing when buying item boxes in bulk.
· Fixed rewards being lost when an error occurred while claiming all mail.
· The Medusa map curse now triggers every 2 waves instead of every wave.
· Fixed damage numbers not being shown at low FPS. 3.3.11 Sep 14 The September Update is here!
- Updated abilities for the featured Heroes, Rabbit and Orc & Boar
- Added a new Ranking Tier
- Renewed the Season Pass, Growth Missions, and event content
- Improved Co-op and PvP battles
- Improved combat information displays
- Additional bug fixes and stability improvements 3.3.10 Aug 31 3.3.9 Update Notes
- PVP Dungeon 2 has been added.
- Fixed an issue where clear rewards were not granted when completing another dungeon after playing a PVP Dungeon.
- Fixed an issue where the hero joystick did not work in PVP Dungeons.
- Improved overall game stability.
- Fixed an issue where the Mount Package was not displayed.
- Fixed an issue where monsters could not be defeated after Stage 900. 3.3.9 Aug 15 新規イベントを追加しました。
ステージ900以降でモンスターの体力が減少しない問題を修正しました。
乗り物パッケージが正常に表示されない問題を修正しました。 3.3.7 Aug 13 “A Princess and a Knight” Rework
- Whenever the Day changes, you can select a weapon for the knight to equip or replace.
- Weapons appear in four grades, with each grade having an equal chance to appear.
- The weapon selection screen now displays the target hand and its currently equipped weapon.
- Skipping a weapon selection now correctly advances the next selection between the left and right hands.
[Ability Changes]
- Level 3: Whenever the princess or knight defeats an enemy, Final Attack and Critical Damage increase by 5%, stacking up to 2,000%. The current bonus is displayed with a buff icon.
- Level 6: Grade 1 and 2 weapons no longer appear; only Grade 3 and 4 weapons appear. Skipping weapon selection grants 1–2 pickaxes.
- Level 9: The knight can equip an additional weapon in the right hand, allowing three weapons in total.
- Level 12: Each time a weapon is equipped or replaced, the princess and knight gain 20% Attack Speed, stacking up to 500%. The current bonus is displayed with a buff icon.
Fixed related issues and improved weapon selection and attack stability. 3.3.6 Aug 1 Version 3.3.5 Update
- The August Season has begun!
- Featured Hero: Squirrel Thunder
- Sub Hero: A Princess and a Knight (Remake)
- Improved Squirrel Thunder’s abilities and exclusive buffs.
- Adjusted the balance of Orc and Boar and Mysterious Armor.
- Normal Stages have been expanded to Stage 970.
- Additional bug fixes and stability improvements have been made.
Thank you for playing UnderDark: Defense! 3.3.4 Jul 31 This update improves PvP matchmaking and convenience features while addressing several issues.
• Improved PvP matchmaking to search a wider score range over time.
• The dungeon menu now retains the last selected tab and ranking list position.
• Your selected discard rarity is now remembered separately for items, pets, relics, and housing.
• Fixed issues with Blink, game speed, mount abilities, and dungeon lists.
We will continue improving the game for a more stable experience. 3.3.3 Jul 18 Improved public random matchmaking. If no match is found within 15 seconds, the search will expand to include players from other regions.
Improved friend room recovery. If the connection is lost after opening another app, the room will be restored automatically using the same room code.
Increased PvP score changes and adjusted how monster HP and movement speed scale over time.
Fixed various Co-op and PvP Dungeon issues involving the 10-Ton Weight, Hell Barrel, Chubby Shark’s anchor, Mysterious Cyclopean Portal, and tower information.
You can now select how many Hero / Tower Contracts to use when you own 100 or more.
Optimized memory usage to reduce crashes during gameplay. 3.3.2 Jul 13 Update Notes
- Fixed an issue where rewards might not be granted correctly or the game could become stuck on the results screen when playing normal stages or auto-play-supported content after using PvP mode.
- Fixed an issue where acquired items might not appear correctly on the results screen.
- Improved overall game stability. 3.3.1 Jul 11 The PvP event is now live!
Compete against other players in real-time PvP battles, climb the rankings, and earn score rewards.
This update also improves PvP stability, reward display, battle UI, and fixes various gameplay issues. 3.3.0 Jul 11 3.2.9 Update Notice
- Fixed multiplayer co-op so equipped heroes, towers, pets, and items now apply their actual levels and bonus options.
- Fixed an issue where the loadout shown in the Daily Co-op/Guild Co-op lobby could differ from the actual in-game loadout.
- Fixed a text issue where pet drop rate increase effects were shown as item drop rate increases on some screens.
We will keep improving the game for a more stable play experience. 3.2.9 Jul 8 - Improved co-op mode stability.
- Fixed some display issues.
- Fixed other bugs and improved overall stability. 3.2.8 Jul 6 This update includes a major overhaul of the multiplayer co-op experience.
We have reworked several co-op systems to improve the overall flow, stability, and long-term foundation of multiplayer play. Because this was a large change, we will continue monitoring reports closely and applying fixes as quickly as possible.
We also focused on in-game performance optimization to make battles feel smoother and more stable across more devices.
After recent server updates, some players experienced unexpected issues. We sincerely apologize for the inconvenience. We are continuing to review reports and logs carefully to prevent unfair losses and improve the overall service stability. 3.2.7 Jul 4 Version 3.2.6 Update
Samurai and Ninja have been improved.
Samurai’s [Target the Strong] boss bonus damage now applies as independent bonus damage. The Lv.9 wave-based attack bonus has been increased from 30% to 60%, and Crescent Slash now flies forward and pierces enemies. At Lv.12, Samurai now starts the game with 4 [Target the Strong] cards.
Ninja now deals 2x damage to monsters with 20% HP or less. Shuriken hits now apply Shadow Marks, increasing damage taken by marked enemies. The mark limit increases further at Lv.12, allowing much higher bonus damage.
Bingo and Board Game events can now run at the same time. You can select and play each event separately from the event screen.
Ranking league promotion has also been improved. Promotion steps now vary by rank, and the number of tiers gained is shown when promoted. 3.2.6 Jun 30 Applied recent server/account system fixes. Improved stability. 3.2.5 Jun 28 [Notice] Cloud Save Button Restored
Hello,
The 'Cloud Save' button that was temporarily disabled has now been fully restored.
You can use the Cloud Save feature normally again.
We sincerely apologize for any inconvenience and thank you for y 3.2.1 Jun 1 [UnderDark:Defense June Update]
- Reaper and Fat Shark heroes are newly revamped.
- Reaper’s minion system is improved.
- Fat Shark’s iron anchor ability is improved.
- Normal stages are expanded up to Stage 940.
- The Bingo event begins.
- Translation and item box related bugs are fixed.
- 1 additional support mercenary ability slot is added. 3.1.9 May 31 [UnderDark: Defense] May Update
- Balance improvements will be applied to Alien Spaceship and Joker characters.
- Alien Spaceship’s Black Hole and Laser abilities will be enhanced.
- Joker’s Card Stack and Surprise Box abilities will be improved.
- Auto option settings for items, mounts, pets, and relics will be added.
- Hero and tower stat calculation details will be improved.
- An issue with the oversized unlock icon in the Silkworm Moth Dungeon will be fixed. 3.1.8 May 21 [UnderDark: Defense] May Update
- A new hero, “Alien Spaceship,” has been added. (Equipped with Laser and Black Hole skills)
- The Joker hero has been revamped, improving attack mechanics and growth elements.
- Normal stages have been expanded up to 930, with new stages added.
- Events have been updated. (Board minigame begins / Bingo and Tower Pass end)
- Balance adjustments have been made to boomerang-type items.
- Some ranking translation errors have been fixed. 3.1.7 Apr 30 - Se corrigió un problema que mostraba el selector de cuentas de Google en cada inicio de sesión. 3.1.6 Apr 19 [Underdark: Defense] April 11 Update
- Guild capacity adjusted to 50 to match server limits and fix UI display issue
- Fixed an issue where weekly spending ranking currency changed abnormally
- Fixed an issue where Goblin Factory Tower was infinitely duplicated due to Imp Hero effect
- Fixed an issue where Sun Ring refresh option did not work properly
- Fixed an issue where buffs were skipped when refreshing after watching ads 3.1.5 Apr 10 [Underdark: Defense] April 1 Update
- Stages are expanded up to 920.
- The Season Pass will be updated.
- Living Tower growth missions are added.
- Living Tower heroes are buffed.
- The “Unexpected Companion Chicken” hero is buffed. 3.1.4 Mar 31 [Underdark: Defense] Update
- Added 4 new towers
- Added new ranking dungeon “Silkworm Moth”
- Added new limited tower pass
- Reduced difficulty of Co-op Dungeon 1
- Fixed an issue where the Buff Reset +1 option did not stack 3.1.3 Mar 22
Underdark:Defense version 3.4.1
Updated At: 2026-10-01
Changes: Version History • October season with Treasure Hunter, Plague Doctor and Agni, refreshed events, stages 981–1000 and the Calcite ranking tier.
• Reworked chat with guild chat, whispers, co-op recruitment, translation, blocking and room sharing.
• Added SSS support hero effects at level 20 and improved relic tower Attack bonuses.
• Expanded equipment filters, safer awakening controls, Send All Gifts and friend request settings.
• Added hero and tower suggestions after repeated stage losses.
• Improved daily and weekly rankings, combat performance and interface stability. 3.4.1 1d ago Updated the App Store screenshots. Game content remains unchanged from the previous version. 3.4.0 5d ago ■ New: Item Awakening
Awaken God grade equipment up to Awakening 5.
· Use items of the same type from Storage as materials — 1, 2, 4, 8 and 16 per stage (31 in total).
· Awakening always succeeds, and your item level and bonus options are kept.
· The main option grows up to 5× its original value, and each item's unique effect grows stronger at every stage.
· An awakened item can only be replaced by one of the same type and grade, and keeps its awakening level.
■ New: Friends
· Add up to 30 friends by exact nickname search or from the suggested list.
· Send free Diamonds to friends once a day each — the recipient gets 1 to 30 Diamonds.
· Gifts can only be claimed on the day they arrive (KST).
■ Friend Roulette Event
· Earn 1 roulette ticket every time you claim a diamond gift from a friend.
· Spin for Gold, Keys, Diamonds, Embers and more. Spin 10 is supported.
· Milestone rewards from 30 up to 300 total spins, including a Legendary Hero, Legendary Tower, God grade item, random Skin and a Unique Mount.
· Runs until September 30 (KST).
■ PvP Season 3 — Boss Counterattack
Every 5 waves, send one of three bosses to your opponent's side. The chance is shared and does not stack.
· Shapeshifter — changes the type of all towers
· Destroyer Lord — destroys 4 random towers
· Herald of Frenzy — while alive, all monsters move 25% faster
New season score rewards and a new season shop are open, and rankings and purchase limits have been reset.
■ Improvements and Bug Fixes
· If Co-op Dungeon stops progressing, you are now notified and returned to the lobby.
· Chain towers now also link with teammates' towers in Co-op Dungeon.
· Co-op room codes now accept codes containing letters and numbers.
· Fixed incorrect pricing when buying item boxes in bulk.
· Fixed rewards being lost when an error occurred while claiming all mail.
· The Medusa map curse now triggers every 2 waves instead of every wave.
· Fixed damage numbers not being shown at low FPS. 3.3.11 Sep 14 The September Update is here!
- Updated abilities for the featured Heroes, Rabbit and Orc & Boar
- Added a new Ranking Tier
- Renewed the Season Pass, Growth Missions, and event content
- Improved Co-op and PvP battles
- Improved combat information displays
- Additional bug fixes and stability improvements 3.3.10 Aug 31 3.3.9 Update Notes
- PVP Dungeon 2 has been added.
- Fixed an issue where clear rewards were not granted when completing another dungeon after playing a PVP Dungeon.
- Fixed an issue where the hero joystick did not work in PVP Dungeons.
- Improved overall game stability.
- Fixed an issue where the Mount Package was not displayed.
- Fixed an issue where monsters could not be defeated after Stage 900. 3.3.9 Aug 15 新規イベントを追加しました。
ステージ900以降でモンスターの体力が減少しない問題を修正しました。
乗り物パッケージが正常に表示されない問題を修正しました。 3.3.7 Aug 13 “A Princess and a Knight” Rework
- Whenever the Day changes, you can select a weapon for the knight to equip or replace.
- Weapons appear in four grades, with each grade having an equal chance to appear.
- The weapon selection screen now displays the target hand and its currently equipped weapon.
- Skipping a weapon selection now correctly advances the next selection between the left and right hands.
[Ability Changes]
- Level 3: Whenever the princess or knight defeats an enemy, Final Attack and Critical Damage increase by 5%, stacking up to 2,000%. The current bonus is displayed with a buff icon.
- Level 6: Grade 1 and 2 weapons no longer appear; only Grade 3 and 4 weapons appear. Skipping weapon selection grants 1–2 pickaxes.
- Level 9: The knight can equip an additional weapon in the right hand, allowing three weapons in total.
- Level 12: Each time a weapon is equipped or replaced, the princess and knight gain 20% Attack Speed, stacking up to 500%. The current bonus is displayed with a buff icon.
Fixed related issues and improved weapon selection and attack stability. 3.3.6 Aug 1 Version 3.3.5 Update
- The August Season has begun!
- Featured Hero: Squirrel Thunder
- Sub Hero: A Princess and a Knight (Remake)
- Improved Squirrel Thunder’s abilities and exclusive buffs.
- Adjusted the balance of Orc and Boar and Mysterious Armor.
- Normal Stages have been expanded to Stage 970.
- Additional bug fixes and stability improvements have been made.
Thank you for playing UnderDark: Defense! 3.3.4 Jul 31 This update improves PvP matchmaking and convenience features while addressing several issues.
• Improved PvP matchmaking to search a wider score range over time.
• The dungeon menu now retains the last selected tab and ranking list position.
• Your selected discard rarity is now remembered separately for items, pets, relics, and housing.
• Fixed issues with Blink, game speed, mount abilities, and dungeon lists.
We will continue improving the game for a more stable experience. 3.3.3 Jul 18 Improved public random matchmaking. If no match is found within 15 seconds, the search will expand to include players from other regions.
Improved friend room recovery. If the connection is lost after opening another app, the room will be restored automatically using the same room code.
Increased PvP score changes and adjusted how monster HP and movement speed scale over time.
Fixed various Co-op and PvP Dungeon issues involving the 10-Ton Weight, Hell Barrel, Chubby Shark’s anchor, Mysterious Cyclopean Portal, and tower information.
You can now select how many Hero / Tower Contracts to use when you own 100 or more.
Optimized memory usage to reduce crashes during gameplay. 3.3.2 Jul 13 Update Notes
- Fixed an issue where rewards might not be granted correctly or the game could become stuck on the results screen when playing normal stages or auto-play-supported content after using PvP mode.
- Fixed an issue where acquired items might not appear correctly on the results screen.
- Improved overall game stability. 3.3.1 Jul 11 The PvP event is now live!
Compete against other players in real-time PvP battles, climb the rankings, and earn score rewards.
This update also improves PvP stability, reward display, battle UI, and fixes various gameplay issues. 3.3.0 Jul 11 3.2.9 Update Notice
- Fixed multiplayer co-op so equipped heroes, towers, pets, and items now apply their actual levels and bonus options.
- Fixed an issue where the loadout shown in the Daily Co-op/Guild Co-op lobby could differ from the actual in-game loadout.
- Fixed a text issue where pet drop rate increase effects were shown as item drop rate increases on some screens.
We will keep improving the game for a more stable play experience. 3.2.9 Jul 8 - Improved co-op mode stability.
- Fixed some display issues.
- Fixed other bugs and improved overall stability. 3.2.8 Jul 6 This update includes a major overhaul of the multiplayer co-op experience.
We have reworked several co-op systems to improve the overall flow, stability, and long-term foundation of multiplayer play. Because this was a large change, we will continue monitoring reports closely and applying fixes as quickly as possible.
We also focused on in-game performance optimization to make battles feel smoother and more stable across more devices.
After recent server updates, some players experienced unexpected issues. We sincerely apologize for the inconvenience. We are continuing to review reports and logs carefully to prevent unfair losses and improve the overall service stability. 3.2.7 Jul 4 Version 3.2.6 Update
Samurai and Ninja have been improved.
Samurai’s [Target the Strong] boss bonus damage now applies as independent bonus damage. The Lv.9 wave-based attack bonus has been increased from 30% to 60%, and Crescent Slash now flies forward and pierces enemies. At Lv.12, Samurai now starts the game with 4 [Target the Strong] cards.
Ninja now deals 2x damage to monsters with 20% HP or less. Shuriken hits now apply Shadow Marks, increasing damage taken by marked enemies. The mark limit increases further at Lv.12, allowing much higher bonus damage.
Bingo and Board Game events can now run at the same time. You can select and play each event separately from the event screen.
Ranking league promotion has also been improved. Promotion steps now vary by rank, and the number of tiers gained is shown when promoted. 3.2.6 Jun 30 Applied recent server/account system fixes. Improved stability. 3.2.5 Jun 28 [Notice] Cloud Save Button Restored
Hello,
The 'Cloud Save' button that was temporarily disabled has now been fully restored.
You can use the Cloud Save feature normally again.
We sincerely apologize for any inconvenience and thank you for y 3.2.1 Jun 1 [UnderDark:Defense June Update]
- Reaper and Fat Shark heroes are newly revamped.
- Reaper’s minion system is improved.
- Fat Shark’s iron anchor ability is improved.
- Normal stages are expanded up to Stage 940.
- The Bingo event begins.
- Translation and item box related bugs are fixed.
- 1 additional support mercenary ability slot is added. 3.1.9 May 31 [UnderDark: Defense] May Update
- Balance improvements will be applied to Alien Spaceship and Joker characters.
- Alien Spaceship’s Black Hole and Laser abilities will be enhanced.
- Joker’s Card Stack and Surprise Box abilities will be improved.
- Auto option settings for items, mounts, pets, and relics will be added.
- Hero and tower stat calculation details will be improved.
- An issue with the oversized unlock icon in the Silkworm Moth Dungeon will be fixed. 3.1.8 May 21 [UnderDark: Defense] May Update
- A new hero, “Alien Spaceship,” has been added. (Equipped with Laser and Black Hole skills)
- The Joker hero has been revamped, improving attack mechanics and growth elements.
- Normal stages have been expanded up to 930, with new stages added.
- Events have been updated. (Board minigame begins / Bingo and Tower Pass end)
- Balance adjustments have been made to boomerang-type items.
- Some ranking translation errors have been fixed. 3.1.7 Apr 30 - Se corrigió un problema que mostraba el selector de cuentas de Google en cada inicio de sesión. 3.1.6 Apr 19 [Underdark: Defense] April 11 Update
- Guild capacity adjusted to 50 to match server limits and fix UI display issue
- Fixed an issue where weekly spending ranking currency changed abnormally
- Fixed an issue where Goblin Factory Tower was infinitely duplicated due to Imp Hero effect
- Fixed an issue where Sun Ring refresh option did not work properly
- Fixed an issue where buffs were skipped when refreshing after watching ads 3.1.5 Apr 10 [Underdark: Defense] April 1 Update
- Stages are expanded up to 920.
- The Season Pass will be updated.
- Living Tower growth missions are added.
- Living Tower heroes are buffed.
- The “Unexpected Companion Chicken” hero is buffed. 3.1.4 Mar 31 [Underdark: Defense] Update
- Added 4 new towers
- Added new ranking dungeon “Silkworm Moth”
- Added new limited tower pass
- Reduced difficulty of Co-op Dungeon 1
- Fixed an issue where the Buff Reset +1 option did not stack 3.1.3 Mar 22
Underdark:Defense version 3.3.11
Updated At: 2026-09-24
Changes: Version History ■ New: Item Awakening
Awaken God grade equipment up to Awakening 5.
· Use items of the same type from Storage as materials — 1, 2, 4, 8 and 16 per stage (31 in total).
· Awakening always succeeds, and your item level and bonus options are kept.
· The main option grows up to 5× its original value, and each item's unique effect grows stronger at every stage.
· An awakened item can only be replaced by one of the same type and grade, and keeps its awakening level.
■ New: Friends
· Add up to 30 friends by exact nickname search or from the suggested list.
· Send free Diamonds to friends once a day each — the recipient gets 1 to 30 Diamonds.
· Gifts can only be claimed on the day they arrive (KST).
■ Friend Roulette Event
· Earn 1 roulette ticket every time you claim a diamond gift from a friend.
· Spin for Gold, Keys, Diamonds, Embers and more. Spin 10 is supported.
· Milestone rewards from 30 up to 300 total spins, including a Legendary Hero, Legendary Tower, God grade item, random Skin and a Unique Mount.
· Runs until September 30 (KST).
■ PvP Season 3 — Boss Counterattack
Every 5 waves, send one of three bosses to your opponent's side. The chance is shared and does not stack.
· Shapeshifter — changes the type of all towers
· Destroyer Lord — destroys 4 random towers
· Herald of Frenzy — while alive, all monsters move 25% faster
New season score rewards and a new season shop are open, and rankings and purchase limits have been reset.
■ Improvements and Bug Fixes
· If Co-op Dungeon stops progressing, you are now notified and returned to the lobby.
· Chain towers now also link with teammates' towers in Co-op Dungeon.
· Co-op room codes now accept codes containing letters and numbers.
· Fixed incorrect pricing when buying item boxes in bulk.
· Fixed rewards being lost when an error occurred while claiming all mail.
· The Medusa map curse now triggers every 2 waves instead of every wave.
· Fixed damage numbers not being shown at low FPS. 3.3.11 Sep 14 The September Update is here!
- Updated abilities for the featured Heroes, Rabbit and Orc & Boar
- Added a new Ranking Tier
- Renewed the Season Pass, Growth Missions, and event content
- Improved Co-op and PvP battles
- Improved combat information displays
- Additional bug fixes and stability improvements 3.3.10 Aug 31 3.3.9 Update Notes
- PVP Dungeon 2 has been added.
- Fixed an issue where clear rewards were not granted when completing another dungeon after playing a PVP Dungeon.
- Fixed an issue where the hero joystick did not work in PVP Dungeons.
- Improved overall game stability.
- Fixed an issue where the Mount Package was not displayed.
- Fixed an issue where monsters could not be defeated after Stage 900. 3.3.9 Aug 15 新規イベントを追加しました。
ステージ900以降でモンスターの体力が減少しない問題を修正しました。
乗り物パッケージが正常に表示されない問題を修正しました。 3.3.7 Aug 13 “A Princess and a Knight” Rework
- Whenever the Day changes, you can select a weapon for the knight to equip or replace.
- Weapons appear in four grades, with each grade having an equal chance to appear.
- The weapon selection screen now displays the target hand and its currently equipped weapon.
- Skipping a weapon selection now correctly advances the next selection between the left and right hands.
[Ability Changes]
- Level 3: Whenever the princess or knight defeats an enemy, Final Attack and Critical Damage increase by 5%, stacking up to 2,000%. The current bonus is displayed with a buff icon.
- Level 6: Grade 1 and 2 weapons no longer appear; only Grade 3 and 4 weapons appear. Skipping weapon selection grants 1–2 pickaxes.
- Level 9: The knight can equip an additional weapon in the right hand, allowing three weapons in total.
- Level 12: Each time a weapon is equipped or replaced, the princess and knight gain 20% Attack Speed, stacking up to 500%. The current bonus is displayed with a buff icon.
Fixed related issues and improved weapon selection and attack stability. 3.3.6 Aug 1 Version 3.3.5 Update
- The August Season has begun!
- Featured Hero: Squirrel Thunder
- Sub Hero: A Princess and a Knight (Remake)
- Improved Squirrel Thunder’s abilities and exclusive buffs.
- Adjusted the balance of Orc and Boar and Mysterious Armor.
- Normal Stages have been expanded to Stage 970.
- Additional bug fixes and stability improvements have been made.
Thank you for playing UnderDark: Defense! 3.3.4 Jul 31 This update improves PvP matchmaking and convenience features while addressing several issues.
• Improved PvP matchmaking to search a wider score range over time.
• The dungeon menu now retains the last selected tab and ranking list position.
• Your selected discard rarity is now remembered separately for items, pets, relics, and housing.
• Fixed issues with Blink, game speed, mount abilities, and dungeon lists.
We will continue improving the game for a more stable experience. 3.3.3 Jul 18 Improved public random matchmaking. If no match is found within 15 seconds, the search will expand to include players from other regions.
Improved friend room recovery. If the connection is lost after opening another app, the room will be restored automatically using the same room code.
Increased PvP score changes and adjusted how monster HP and movement speed scale over time.
Fixed various Co-op and PvP Dungeon issues involving the 10-Ton Weight, Hell Barrel, Chubby Shark’s anchor, Mysterious Cyclopean Portal, and tower information.
You can now select how many Hero / Tower Contracts to use when you own 100 or more.
Optimized memory usage to reduce crashes during gameplay. 3.3.2 Jul 13 Update Notes
- Fixed an issue where rewards might not be granted correctly or the game could become stuck on the results screen when playing normal stages or auto-play-supported content after using PvP mode.
- Fixed an issue where acquired items might not appear correctly on the results screen.
- Improved overall game stability. 3.3.1 Jul 11 The PvP event is now live!
Compete against other players in real-time PvP battles, climb the rankings, and earn score rewards.
This update also improves PvP stability, reward display, battle UI, and fixes various gameplay issues. 3.3.0 Jul 11 3.2.9 Update Notice
- Fixed multiplayer co-op so equipped heroes, towers, pets, and items now apply their actual levels and bonus options.
- Fixed an issue where the loadout shown in the Daily Co-op/Guild Co-op lobby could differ from the actual in-game loadout.
- Fixed a text issue where pet drop rate increase effects were shown as item drop rate increases on some screens.
We will keep improving the game for a more stable play experience. 3.2.9 Jul 8 - Improved co-op mode stability.
- Fixed some display issues.
- Fixed other bugs and improved overall stability. 3.2.8 Jul 6 This update includes a major overhaul of the multiplayer co-op experience.
We have reworked several co-op systems to improve the overall flow, stability, and long-term foundation of multiplayer play. Because this was a large change, we will continue monitoring reports closely and applying fixes as quickly as possible.
We also focused on in-game performance optimization to make battles feel smoother and more stable across more devices.
After recent server updates, some players experienced unexpected issues. We sincerely apologize for the inconvenience. We are continuing to review reports and logs carefully to prevent unfair losses and improve the overall service stability. 3.2.7 Jul 4 Version 3.2.6 Update
Samurai and Ninja have been improved.
Samurai’s [Target the Strong] boss bonus damage now applies as independent bonus damage. The Lv.9 wave-based attack bonus has been increased from 30% to 60%, and Crescent Slash now flies forward and pierces enemies. At Lv.12, Samurai now starts the game with 4 [Target the Strong] cards.
Ninja now deals 2x damage to monsters with 20% HP or less. Shuriken hits now apply Shadow Marks, increasing damage taken by marked enemies. The mark limit increases further at Lv.12, allowing much higher bonus damage.
Bingo and Board Game events can now run at the same time. You can select and play each event separately from the event screen.
Ranking league promotion has also been improved. Promotion steps now vary by rank, and the number of tiers gained is shown when promoted. 3.2.6 Jun 30 Applied recent server/account system fixes. Improved stability. 3.2.5 Jun 28 [Notice] Cloud Save Button Restored
Hello,
The 'Cloud Save' button that was temporarily disabled has now been fully restored.
You can use the Cloud Save feature normally again.
We sincerely apologize for any inconvenience and thank you for y 3.2.1 Jun 1 [UnderDark:Defense June Update]
- Reaper and Fat Shark heroes are newly revamped.
- Reaper’s minion system is improved.
- Fat Shark’s iron anchor ability is improved.
- Normal stages are expanded up to Stage 940.
- The Bingo event begins.
- Translation and item box related bugs are fixed.
- 1 additional support mercenary ability slot is added. 3.1.9 May 31 [UnderDark: Defense] May Update
- Balance improvements will be applied to Alien Spaceship and Joker characters.
- Alien Spaceship’s Black Hole and Laser abilities will be enhanced.
- Joker’s Card Stack and Surprise Box abilities will be improved.
- Auto option settings for items, mounts, pets, and relics will be added.
- Hero and tower stat calculation details will be improved.
- An issue with the oversized unlock icon in the Silkworm Moth Dungeon will be fixed. 3.1.8 May 21 [UnderDark: Defense] May Update
- A new hero, “Alien Spaceship,” has been added. (Equipped with Laser and Black Hole skills)
- The Joker hero has been revamped, improving attack mechanics and growth elements.
- Normal stages have been expanded up to 930, with new stages added.
- Events have been updated. (Board minigame begins / Bingo and Tower Pass end)
- Balance adjustments have been made to boomerang-type items.
- Some ranking translation errors have been fixed. 3.1.7 Apr 30 - Se corrigió un problema que mostraba el selector de cuentas de Google en cada inicio de sesión. 3.1.6 Apr 19 [Underdark: Defense] April 11 Update
- Guild capacity adjusted to 50 to match server limits and fix UI display issue
- Fixed an issue where weekly spending ranking currency changed abnormally
- Fixed an issue where Goblin Factory Tower was infinitely duplicated due to Imp Hero effect
- Fixed an issue where Sun Ring refresh option did not work properly
- Fixed an issue where buffs were skipped when refreshing after watching ads 3.1.5 Apr 10 [Underdark: Defense] April 1 Update
- Stages are expanded up to 920.
- The Season Pass will be updated.
- Living Tower growth missions are added.
- Living Tower heroes are buffed.
- The “Unexpected Companion Chicken” hero is buffed. 3.1.4 Mar 31 [Underdark: Defense] Update
- Added 4 new towers
- Added new ranking dungeon “Silkworm Moth”
- Added new limited tower pass
- Reduced difficulty of Co-op Dungeon 1
- Fixed an issue where the Buff Reset +1 option did not stack 3.1.3 Mar 22 [Underdark: Defense] March 14 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.2 Mar 14 [Underdark: Defense] March 13 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.1 Mar 12
Underdark:Defense version 3.3.11
Updated At: 2026-09-17
Changes: Version History ■ New: Item Awakening
Awaken God grade equipment up to Awakening 5.
· Use items of the same type from Storage as materials — 1, 2, 4, 8 and 16 per stage (31 in total).
· Awakening always succeeds, and your item level and bonus options are kept.
· The main option grows up to 5× its original value, and each item's unique effect grows stronger at every stage.
· An awakened item can only be replaced by one of the same type and grade, and keeps its awakening level.
■ New: Friends
· Add up to 30 friends by exact nickname search or from the suggested list.
· Send free Diamonds to friends once a day each — the recipient gets 1 to 30 Diamonds.
· Gifts can only be claimed on the day they arrive (KST).
■ Friend Roulette Event
· Earn 1 roulette ticket every time you claim a diamond gift from a friend.
· Spin for Gold, Keys, Diamonds, Embers and more. Spin 10 is supported.
· Milestone rewards from 30 up to 300 total spins, including a Legendary Hero, Legendary Tower, God grade item, random Skin and a Unique Mount.
· Runs until September 30 (KST).
■ PvP Season 3 — Boss Counterattack
Every 5 waves, send one of three bosses to your opponent's side. The chance is shared and does not stack.
· Shapeshifter — changes the type of all towers
· Destroyer Lord — destroys 4 random towers
· Herald of Frenzy — while alive, all monsters move 25% faster
New season score rewards and a new season shop are open, and rankings and purchase limits have been reset.
■ Improvements and Bug Fixes
· If Co-op Dungeon stops progressing, you are now notified and returned to the lobby.
· Chain towers now also link with teammates' towers in Co-op Dungeon.
· Co-op room codes now accept codes containing letters and numbers.
· Fixed incorrect pricing when buying item boxes in bulk.
· Fixed rewards being lost when an error occurred while claiming all mail.
· The Medusa map curse now triggers every 2 waves instead of every wave.
· Fixed damage numbers not being shown at low FPS. 3.3.11 3d ago The September Update is here!
- Updated abilities for the featured Heroes, Rabbit and Orc & Boar
- Added a new Ranking Tier
- Renewed the Season Pass, Growth Missions, and event content
- Improved Co-op and PvP battles
- Improved combat information displays
- Additional bug fixes and stability improvements 3.3.10 Aug 31 3.3.9 Update Notes
- PVP Dungeon 2 has been added.
- Fixed an issue where clear rewards were not granted when completing another dungeon after playing a PVP Dungeon.
- Fixed an issue where the hero joystick did not work in PVP Dungeons.
- Improved overall game stability.
- Fixed an issue where the Mount Package was not displayed.
- Fixed an issue where monsters could not be defeated after Stage 900. 3.3.9 Aug 15 新規イベントを追加しました。
ステージ900以降でモンスターの体力が減少しない問題を修正しました。
乗り物パッケージが正常に表示されない問題を修正しました。 3.3.7 Aug 13 “A Princess and a Knight” Rework
- Whenever the Day changes, you can select a weapon for the knight to equip or replace.
- Weapons appear in four grades, with each grade having an equal chance to appear.
- The weapon selection screen now displays the target hand and its currently equipped weapon.
- Skipping a weapon selection now correctly advances the next selection between the left and right hands.
[Ability Changes]
- Level 3: Whenever the princess or knight defeats an enemy, Final Attack and Critical Damage increase by 5%, stacking up to 2,000%. The current bonus is displayed with a buff icon.
- Level 6: Grade 1 and 2 weapons no longer appear; only Grade 3 and 4 weapons appear. Skipping weapon selection grants 1–2 pickaxes.
- Level 9: The knight can equip an additional weapon in the right hand, allowing three weapons in total.
- Level 12: Each time a weapon is equipped or replaced, the princess and knight gain 20% Attack Speed, stacking up to 500%. The current bonus is displayed with a buff icon.
Fixed related issues and improved weapon selection and attack stability. 3.3.6 Aug 1 Version 3.3.5 Update
- The August Season has begun!
- Featured Hero: Squirrel Thunder
- Sub Hero: A Princess and a Knight (Remake)
- Improved Squirrel Thunder’s abilities and exclusive buffs.
- Adjusted the balance of Orc and Boar and Mysterious Armor.
- Normal Stages have been expanded to Stage 970.
- Additional bug fixes and stability improvements have been made.
Thank you for playing UnderDark: Defense! 3.3.4 Jul 31 This update improves PvP matchmaking and convenience features while addressing several issues.
• Improved PvP matchmaking to search a wider score range over time.
• The dungeon menu now retains the last selected tab and ranking list position.
• Your selected discard rarity is now remembered separately for items, pets, relics, and housing.
• Fixed issues with Blink, game speed, mount abilities, and dungeon lists.
We will continue improving the game for a more stable experience. 3.3.3 Jul 18 Improved public random matchmaking. If no match is found within 15 seconds, the search will expand to include players from other regions.
Improved friend room recovery. If the connection is lost after opening another app, the room will be restored automatically using the same room code.
Increased PvP score changes and adjusted how monster HP and movement speed scale over time.
Fixed various Co-op and PvP Dungeon issues involving the 10-Ton Weight, Hell Barrel, Chubby Shark’s anchor, Mysterious Cyclopean Portal, and tower information.
You can now select how many Hero / Tower Contracts to use when you own 100 or more.
Optimized memory usage to reduce crashes during gameplay. 3.3.2 Jul 13 Update Notes
- Fixed an issue where rewards might not be granted correctly or the game could become stuck on the results screen when playing normal stages or auto-play-supported content after using PvP mode.
- Fixed an issue where acquired items might not appear correctly on the results screen.
- Improved overall game stability. 3.3.1 Jul 11 The PvP event is now live!
Compete against other players in real-time PvP battles, climb the rankings, and earn score rewards.
This update also improves PvP stability, reward display, battle UI, and fixes various gameplay issues. 3.3.0 Jul 11 3.2.9 Update Notice
- Fixed multiplayer co-op so equipped heroes, towers, pets, and items now apply their actual levels and bonus options.
- Fixed an issue where the loadout shown in the Daily Co-op/Guild Co-op lobby could differ from the actual in-game loadout.
- Fixed a text issue where pet drop rate increase effects were shown as item drop rate increases on some screens.
We will keep improving the game for a more stable play experience. 3.2.9 Jul 8 - Improved co-op mode stability.
- Fixed some display issues.
- Fixed other bugs and improved overall stability. 3.2.8 Jul 6 This update includes a major overhaul of the multiplayer co-op experience.
We have reworked several co-op systems to improve the overall flow, stability, and long-term foundation of multiplayer play. Because this was a large change, we will continue monitoring reports closely and applying fixes as quickly as possible.
We also focused on in-game performance optimization to make battles feel smoother and more stable across more devices.
After recent server updates, some players experienced unexpected issues. We sincerely apologize for the inconvenience. We are continuing to review reports and logs carefully to prevent unfair losses and improve the overall service stability. 3.2.7 Jul 4 Version 3.2.6 Update
Samurai and Ninja have been improved.
Samurai’s [Target the Strong] boss bonus damage now applies as independent bonus damage. The Lv.9 wave-based attack bonus has been increased from 30% to 60%, and Crescent Slash now flies forward and pierces enemies. At Lv.12, Samurai now starts the game with 4 [Target the Strong] cards.
Ninja now deals 2x damage to monsters with 20% HP or less. Shuriken hits now apply Shadow Marks, increasing damage taken by marked enemies. The mark limit increases further at Lv.12, allowing much higher bonus damage.
Bingo and Board Game events can now run at the same time. You can select and play each event separately from the event screen.
Ranking league promotion has also been improved. Promotion steps now vary by rank, and the number of tiers gained is shown when promoted. 3.2.6 Jun 30 Applied recent server/account system fixes. Improved stability. 3.2.5 Jun 28 [Notice] Cloud Save Button Restored
Hello,
The 'Cloud Save' button that was temporarily disabled has now been fully restored.
You can use the Cloud Save feature normally again.
We sincerely apologize for any inconvenience and thank you for y 3.2.1 Jun 1 [UnderDark:Defense June Update]
- Reaper and Fat Shark heroes are newly revamped.
- Reaper’s minion system is improved.
- Fat Shark’s iron anchor ability is improved.
- Normal stages are expanded up to Stage 940.
- The Bingo event begins.
- Translation and item box related bugs are fixed.
- 1 additional support mercenary ability slot is added. 3.1.9 May 31 [UnderDark: Defense] May Update
- Balance improvements will be applied to Alien Spaceship and Joker characters.
- Alien Spaceship’s Black Hole and Laser abilities will be enhanced.
- Joker’s Card Stack and Surprise Box abilities will be improved.
- Auto option settings for items, mounts, pets, and relics will be added.
- Hero and tower stat calculation details will be improved.
- An issue with the oversized unlock icon in the Silkworm Moth Dungeon will be fixed. 3.1.8 May 21 [UnderDark: Defense] May Update
- A new hero, “Alien Spaceship,” has been added. (Equipped with Laser and Black Hole skills)
- The Joker hero has been revamped, improving attack mechanics and growth elements.
- Normal stages have been expanded up to 930, with new stages added.
- Events have been updated. (Board minigame begins / Bingo and Tower Pass end)
- Balance adjustments have been made to boomerang-type items.
- Some ranking translation errors have been fixed. 3.1.7 Apr 30 - Se corrigió un problema que mostraba el selector de cuentas de Google en cada inicio de sesión. 3.1.6 Apr 19 [Underdark: Defense] April 11 Update
- Guild capacity adjusted to 50 to match server limits and fix UI display issue
- Fixed an issue where weekly spending ranking currency changed abnormally
- Fixed an issue where Goblin Factory Tower was infinitely duplicated due to Imp Hero effect
- Fixed an issue where Sun Ring refresh option did not work properly
- Fixed an issue where buffs were skipped when refreshing after watching ads 3.1.5 Apr 10 [Underdark: Defense] April 1 Update
- Stages are expanded up to 920.
- The Season Pass will be updated.
- Living Tower growth missions are added.
- Living Tower heroes are buffed.
- The “Unexpected Companion Chicken” hero is buffed. 3.1.4 Mar 31 [Underdark: Defense] Update
- Added 4 new towers
- Added new ranking dungeon “Silkworm Moth”
- Added new limited tower pass
- Reduced difficulty of Co-op Dungeon 1
- Fixed an issue where the Buff Reset +1 option did not stack 3.1.3 Mar 22 [Underdark: Defense] March 14 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.2 Mar 14 [Underdark: Defense] March 13 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.1 Mar 12
Underdark:Defense version 3.3.10
Updated At: 2026-09-10
Changes: Version History The September Update is here!
- Updated abilities for the featured Heroes, Rabbit and Orc & Boar
- Added a new Ranking Tier
- Renewed the Season Pass, Growth Missions, and event content
- Improved Co-op and PvP battles
- Improved combat information displays
- Additional bug fixes and stability improvements 3.3.10 Aug 31 3.3.9 Update Notes
- PVP Dungeon 2 has been added.
- Fixed an issue where clear rewards were not granted when completing another dungeon after playing a PVP Dungeon.
- Fixed an issue where the hero joystick did not work in PVP Dungeons.
- Improved overall game stability.
- Fixed an issue where the Mount Package was not displayed.
- Fixed an issue where monsters could not be defeated after Stage 900. 3.3.9 Aug 15 新規イベントを追加しました。
ステージ900以降でモンスターの体力が減少しない問題を修正しました。
乗り物パッケージが正常に表示されない問題を修正しました。 3.3.7 Aug 13 “A Princess and a Knight” Rework
- Whenever the Day changes, you can select a weapon for the knight to equip or replace.
- Weapons appear in four grades, with each grade having an equal chance to appear.
- The weapon selection screen now displays the target hand and its currently equipped weapon.
- Skipping a weapon selection now correctly advances the next selection between the left and right hands.
[Ability Changes]
- Level 3: Whenever the princess or knight defeats an enemy, Final Attack and Critical Damage increase by 5%, stacking up to 2,000%. The current bonus is displayed with a buff icon.
- Level 6: Grade 1 and 2 weapons no longer appear; only Grade 3 and 4 weapons appear. Skipping weapon selection grants 1–2 pickaxes.
- Level 9: The knight can equip an additional weapon in the right hand, allowing three weapons in total.
- Level 12: Each time a weapon is equipped or replaced, the princess and knight gain 20% Attack Speed, stacking up to 500%. The current bonus is displayed with a buff icon.
Fixed related issues and improved weapon selection and attack stability. 3.3.6 Aug 1 Version 3.3.5 Update
- The August Season has begun!
- Featured Hero: Squirrel Thunder
- Sub Hero: A Princess and a Knight (Remake)
- Improved Squirrel Thunder’s abilities and exclusive buffs.
- Adjusted the balance of Orc and Boar and Mysterious Armor.
- Normal Stages have been expanded to Stage 970.
- Additional bug fixes and stability improvements have been made.
Thank you for playing UnderDark: Defense! 3.3.4 Jul 31 This update improves PvP matchmaking and convenience features while addressing several issues.
• Improved PvP matchmaking to search a wider score range over time.
• The dungeon menu now retains the last selected tab and ranking list position.
• Your selected discard rarity is now remembered separately for items, pets, relics, and housing.
• Fixed issues with Blink, game speed, mount abilities, and dungeon lists.
We will continue improving the game for a more stable experience. 3.3.3 Jul 18 Improved public random matchmaking. If no match is found within 15 seconds, the search will expand to include players from other regions.
Improved friend room recovery. If the connection is lost after opening another app, the room will be restored automatically using the same room code.
Increased PvP score changes and adjusted how monster HP and movement speed scale over time.
Fixed various Co-op and PvP Dungeon issues involving the 10-Ton Weight, Hell Barrel, Chubby Shark’s anchor, Mysterious Cyclopean Portal, and tower information.
You can now select how many Hero / Tower Contracts to use when you own 100 or more.
Optimized memory usage to reduce crashes during gameplay. 3.3.2 Jul 13 Update Notes
- Fixed an issue where rewards might not be granted correctly or the game could become stuck on the results screen when playing normal stages or auto-play-supported content after using PvP mode.
- Fixed an issue where acquired items might not appear correctly on the results screen.
- Improved overall game stability. 3.3.1 Jul 11 The PvP event is now live!
Compete against other players in real-time PvP battles, climb the rankings, and earn score rewards.
This update also improves PvP stability, reward display, battle UI, and fixes various gameplay issues. 3.3.0 Jul 11 3.2.9 Update Notice
- Fixed multiplayer co-op so equipped heroes, towers, pets, and items now apply their actual levels and bonus options.
- Fixed an issue where the loadout shown in the Daily Co-op/Guild Co-op lobby could differ from the actual in-game loadout.
- Fixed a text issue where pet drop rate increase effects were shown as item drop rate increases on some screens.
We will keep improving the game for a more stable play experience. 3.2.9 Jul 8 - Improved co-op mode stability.
- Fixed some display issues.
- Fixed other bugs and improved overall stability. 3.2.8 Jul 6 This update includes a major overhaul of the multiplayer co-op experience.
We have reworked several co-op systems to improve the overall flow, stability, and long-term foundation of multiplayer play. Because this was a large change, we will continue monitoring reports closely and applying fixes as quickly as possible.
We also focused on in-game performance optimization to make battles feel smoother and more stable across more devices.
After recent server updates, some players experienced unexpected issues. We sincerely apologize for the inconvenience. We are continuing to review reports and logs carefully to prevent unfair losses and improve the overall service stability. 3.2.7 Jul 4 Version 3.2.6 Update
Samurai and Ninja have been improved.
Samurai’s [Target the Strong] boss bonus damage now applies as independent bonus damage. The Lv.9 wave-based attack bonus has been increased from 30% to 60%, and Crescent Slash now flies forward and pierces enemies. At Lv.12, Samurai now starts the game with 4 [Target the Strong] cards.
Ninja now deals 2x damage to monsters with 20% HP or less. Shuriken hits now apply Shadow Marks, increasing damage taken by marked enemies. The mark limit increases further at Lv.12, allowing much higher bonus damage.
Bingo and Board Game events can now run at the same time. You can select and play each event separately from the event screen.
Ranking league promotion has also been improved. Promotion steps now vary by rank, and the number of tiers gained is shown when promoted. 3.2.6 Jun 30 Applied recent server/account system fixes. Improved stability. 3.2.5 Jun 28 [Notice] Cloud Save Button Restored
Hello,
The 'Cloud Save' button that was temporarily disabled has now been fully restored.
You can use the Cloud Save feature normally again.
We sincerely apologize for any inconvenience and thank you for y 3.2.1 Jun 1 [UnderDark:Defense June Update]
- Reaper and Fat Shark heroes are newly revamped.
- Reaper’s minion system is improved.
- Fat Shark’s iron anchor ability is improved.
- Normal stages are expanded up to Stage 940.
- The Bingo event begins.
- Translation and item box related bugs are fixed.
- 1 additional support mercenary ability slot is added. 3.1.9 May 31 [UnderDark: Defense] May Update
- Balance improvements will be applied to Alien Spaceship and Joker characters.
- Alien Spaceship’s Black Hole and Laser abilities will be enhanced.
- Joker’s Card Stack and Surprise Box abilities will be improved.
- Auto option settings for items, mounts, pets, and relics will be added.
- Hero and tower stat calculation details will be improved.
- An issue with the oversized unlock icon in the Silkworm Moth Dungeon will be fixed. 3.1.8 May 21 [UnderDark: Defense] May Update
- A new hero, “Alien Spaceship,” has been added. (Equipped with Laser and Black Hole skills)
- The Joker hero has been revamped, improving attack mechanics and growth elements.
- Normal stages have been expanded up to 930, with new stages added.
- Events have been updated. (Board minigame begins / Bingo and Tower Pass end)
- Balance adjustments have been made to boomerang-type items.
- Some ranking translation errors have been fixed. 3.1.7 Apr 30 - Se corrigió un problema que mostraba el selector de cuentas de Google en cada inicio de sesión. 3.1.6 Apr 19 [Underdark: Defense] April 11 Update
- Guild capacity adjusted to 50 to match server limits and fix UI display issue
- Fixed an issue where weekly spending ranking currency changed abnormally
- Fixed an issue where Goblin Factory Tower was infinitely duplicated due to Imp Hero effect
- Fixed an issue where Sun Ring refresh option did not work properly
- Fixed an issue where buffs were skipped when refreshing after watching ads 3.1.5 Apr 10 [Underdark: Defense] April 1 Update
- Stages are expanded up to 920.
- The Season Pass will be updated.
- Living Tower growth missions are added.
- Living Tower heroes are buffed.
- The “Unexpected Companion Chicken” hero is buffed. 3.1.4 Mar 31 [Underdark: Defense] Update
- Added 4 new towers
- Added new ranking dungeon “Silkworm Moth”
- Added new limited tower pass
- Reduced difficulty of Co-op Dungeon 1
- Fixed an issue where the Buff Reset +1 option did not stack 3.1.3 Mar 22 [Underdark: Defense] March 14 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.2 Mar 14 [Underdark: Defense] March 13 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.1 Mar 12 Fixed an issue where the weekly ranking currency changed at the wrong time.
The weekly ranking currency has been changed back to Diamonds. 3.1.0 Mar 7
Underdark:Defense version 3.3.10
Updated At: 2026-09-03
Changes: Version History The September Update is here!
- Updated abilities for the featured Heroes, Rabbit and Orc & Boar
- Added a new Ranking Tier
- Renewed the Season Pass, Growth Missions, and event content
- Improved Co-op and PvP battles
- Improved combat information displays
- Additional bug fixes and stability improvements 3.3.10 3d ago 3.3.9 Update Notes
- PVP Dungeon 2 has been added.
- Fixed an issue where clear rewards were not granted when completing another dungeon after playing a PVP Dungeon.
- Fixed an issue where the hero joystick did not work in PVP Dungeons.
- Improved overall game stability.
- Fixed an issue where the Mount Package was not displayed.
- Fixed an issue where monsters could not be defeated after Stage 900. 3.3.9 Aug 15 新規イベントを追加しました。
ステージ900以降でモンスターの体力が減少しない問題を修正しました。
乗り物パッケージが正常に表示されない問題を修正しました。 3.3.7 Aug 13 “A Princess and a Knight” Rework
- Whenever the Day changes, you can select a weapon for the knight to equip or replace.
- Weapons appear in four grades, with each grade having an equal chance to appear.
- The weapon selection screen now displays the target hand and its currently equipped weapon.
- Skipping a weapon selection now correctly advances the next selection between the left and right hands.
[Ability Changes]
- Level 3: Whenever the princess or knight defeats an enemy, Final Attack and Critical Damage increase by 5%, stacking up to 2,000%. The current bonus is displayed with a buff icon.
- Level 6: Grade 1 and 2 weapons no longer appear; only Grade 3 and 4 weapons appear. Skipping weapon selection grants 1–2 pickaxes.
- Level 9: The knight can equip an additional weapon in the right hand, allowing three weapons in total.
- Level 12: Each time a weapon is equipped or replaced, the princess and knight gain 20% Attack Speed, stacking up to 500%. The current bonus is displayed with a buff icon.
Fixed related issues and improved weapon selection and attack stability. 3.3.6 Aug 1 Version 3.3.5 Update
- The August Season has begun!
- Featured Hero: Squirrel Thunder
- Sub Hero: A Princess and a Knight (Remake)
- Improved Squirrel Thunder’s abilities and exclusive buffs.
- Adjusted the balance of Orc and Boar and Mysterious Armor.
- Normal Stages have been expanded to Stage 970.
- Additional bug fixes and stability improvements have been made.
Thank you for playing UnderDark: Defense! 3.3.4 Jul 31 This update improves PvP matchmaking and convenience features while addressing several issues.
• Improved PvP matchmaking to search a wider score range over time.
• The dungeon menu now retains the last selected tab and ranking list position.
• Your selected discard rarity is now remembered separately for items, pets, relics, and housing.
• Fixed issues with Blink, game speed, mount abilities, and dungeon lists.
We will continue improving the game for a more stable experience. 3.3.3 Jul 18 Improved public random matchmaking. If no match is found within 15 seconds, the search will expand to include players from other regions.
Improved friend room recovery. If the connection is lost after opening another app, the room will be restored automatically using the same room code.
Increased PvP score changes and adjusted how monster HP and movement speed scale over time.
Fixed various Co-op and PvP Dungeon issues involving the 10-Ton Weight, Hell Barrel, Chubby Shark’s anchor, Mysterious Cyclopean Portal, and tower information.
You can now select how many Hero / Tower Contracts to use when you own 100 or more.
Optimized memory usage to reduce crashes during gameplay. 3.3.2 Jul 13 Update Notes
- Fixed an issue where rewards might not be granted correctly or the game could become stuck on the results screen when playing normal stages or auto-play-supported content after using PvP mode.
- Fixed an issue where acquired items might not appear correctly on the results screen.
- Improved overall game stability. 3.3.1 Jul 11 The PvP event is now live!
Compete against other players in real-time PvP battles, climb the rankings, and earn score rewards.
This update also improves PvP stability, reward display, battle UI, and fixes various gameplay issues. 3.3.0 Jul 11 3.2.9 Update Notice
- Fixed multiplayer co-op so equipped heroes, towers, pets, and items now apply their actual levels and bonus options.
- Fixed an issue where the loadout shown in the Daily Co-op/Guild Co-op lobby could differ from the actual in-game loadout.
- Fixed a text issue where pet drop rate increase effects were shown as item drop rate increases on some screens.
We will keep improving the game for a more stable play experience. 3.2.9 Jul 8 - Improved co-op mode stability.
- Fixed some display issues.
- Fixed other bugs and improved overall stability. 3.2.8 Jul 6 This update includes a major overhaul of the multiplayer co-op experience.
We have reworked several co-op systems to improve the overall flow, stability, and long-term foundation of multiplayer play. Because this was a large change, we will continue monitoring reports closely and applying fixes as quickly as possible.
We also focused on in-game performance optimization to make battles feel smoother and more stable across more devices.
After recent server updates, some players experienced unexpected issues. We sincerely apologize for the inconvenience. We are continuing to review reports and logs carefully to prevent unfair losses and improve the overall service stability. 3.2.7 Jul 4 Version 3.2.6 Update
Samurai and Ninja have been improved.
Samurai’s [Target the Strong] boss bonus damage now applies as independent bonus damage. The Lv.9 wave-based attack bonus has been increased from 30% to 60%, and Crescent Slash now flies forward and pierces enemies. At Lv.12, Samurai now starts the game with 4 [Target the Strong] cards.
Ninja now deals 2x damage to monsters with 20% HP or less. Shuriken hits now apply Shadow Marks, increasing damage taken by marked enemies. The mark limit increases further at Lv.12, allowing much higher bonus damage.
Bingo and Board Game events can now run at the same time. You can select and play each event separately from the event screen.
Ranking league promotion has also been improved. Promotion steps now vary by rank, and the number of tiers gained is shown when promoted. 3.2.6 Jun 30 Applied recent server/account system fixes. Improved stability. 3.2.5 Jun 28 [Notice] Cloud Save Button Restored
Hello,
The 'Cloud Save' button that was temporarily disabled has now been fully restored.
You can use the Cloud Save feature normally again.
We sincerely apologize for any inconvenience and thank you for y 3.2.1 Jun 1 [UnderDark:Defense June Update]
- Reaper and Fat Shark heroes are newly revamped.
- Reaper’s minion system is improved.
- Fat Shark’s iron anchor ability is improved.
- Normal stages are expanded up to Stage 940.
- The Bingo event begins.
- Translation and item box related bugs are fixed.
- 1 additional support mercenary ability slot is added. 3.1.9 May 31 [UnderDark: Defense] May Update
- Balance improvements will be applied to Alien Spaceship and Joker characters.
- Alien Spaceship’s Black Hole and Laser abilities will be enhanced.
- Joker’s Card Stack and Surprise Box abilities will be improved.
- Auto option settings for items, mounts, pets, and relics will be added.
- Hero and tower stat calculation details will be improved.
- An issue with the oversized unlock icon in the Silkworm Moth Dungeon will be fixed. 3.1.8 May 21 [UnderDark: Defense] May Update
- A new hero, “Alien Spaceship,” has been added. (Equipped with Laser and Black Hole skills)
- The Joker hero has been revamped, improving attack mechanics and growth elements.
- Normal stages have been expanded up to 930, with new stages added.
- Events have been updated. (Board minigame begins / Bingo and Tower Pass end)
- Balance adjustments have been made to boomerang-type items.
- Some ranking translation errors have been fixed. 3.1.7 Apr 30 - Se corrigió un problema que mostraba el selector de cuentas de Google en cada inicio de sesión. 3.1.6 Apr 19 [Underdark: Defense] April 11 Update
- Guild capacity adjusted to 50 to match server limits and fix UI display issue
- Fixed an issue where weekly spending ranking currency changed abnormally
- Fixed an issue where Goblin Factory Tower was infinitely duplicated due to Imp Hero effect
- Fixed an issue where Sun Ring refresh option did not work properly
- Fixed an issue where buffs were skipped when refreshing after watching ads 3.1.5 Apr 10 This app has been updated by Apple to prepare for watchOS 27 compatibility. No new features are included.
[Underdark: Defense] April 1 Update
- Stages are expanded up to 920.
- The Season Pass will be updated.
- Living Tower growth missions are added.
- Living Tower heroes are buffed.
- The “Unexpected Companion Chicken” hero is buffed. 3.1.4 Mar 31 [Underdark: Defense] Update
- Added 4 new towers
- Added new ranking dungeon “Silkworm Moth”
- Added new limited tower pass
- Reduced difficulty of Co-op Dungeon 1
- Fixed an issue where the Buff Reset +1 option did not stack 3.1.3 Mar 22 [Underdark: Defense] March 14 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.2 Mar 14 [Underdark: Defense] March 13 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.1 Mar 12 Fixed an issue where the weekly ranking currency changed at the wrong time.
The weekly ranking currency has been changed back to Diamonds. 3.1.0 Mar 7
Underdark:Defense version 3.3.9
Updated At: 2026-08-21
Changes: Version History 3.3.9 Update Notes
- PVP Dungeon 2 has been added.
- Fixed an issue where clear rewards were not granted when completing another dungeon after playing a PVP Dungeon.
- Fixed an issue where the hero joystick did not work in PVP Dungeons.
- Improved overall game stability.
- Fixed an issue where the Mount Package was not displayed.
- Fixed an issue where monsters could not be defeated after Stage 900. 3.3.9 6d ago 新規イベントを追加しました。
ステージ900以降でモンスターの体力が減少しない問題を修正しました。
乗り物パッケージが正常に表示されない問題を修正しました。 3.3.7 Aug 13 “A Princess and a Knight” Rework
- Whenever the Day changes, you can select a weapon for the knight to equip or replace.
- Weapons appear in four grades, with each grade having an equal chance to appear.
- The weapon selection screen now displays the target hand and its currently equipped weapon.
- Skipping a weapon selection now correctly advances the next selection between the left and right hands.
[Ability Changes]
- Level 3: Whenever the princess or knight defeats an enemy, Final Attack and Critical Damage increase by 5%, stacking up to 2,000%. The current bonus is displayed with a buff icon.
- Level 6: Grade 1 and 2 weapons no longer appear; only Grade 3 and 4 weapons appear. Skipping weapon selection grants 1–2 pickaxes.
- Level 9: The knight can equip an additional weapon in the right hand, allowing three weapons in total.
- Level 12: Each time a weapon is equipped or replaced, the princess and knight gain 20% Attack Speed, stacking up to 500%. The current bonus is displayed with a buff icon.
Fixed related issues and improved weapon selection and attack stability. 3.3.6 Aug 1 Version 3.3.5 Update
- The August Season has begun!
- Featured Hero: Squirrel Thunder
- Sub Hero: A Princess and a Knight (Remake)
- Improved Squirrel Thunder’s abilities and exclusive buffs.
- Adjusted the balance of Orc and Boar and Mysterious Armor.
- Normal Stages have been expanded to Stage 970.
- Additional bug fixes and stability improvements have been made.
Thank you for playing UnderDark: Defense! 3.3.4 Jul 31 This update improves PvP matchmaking and convenience features while addressing several issues.
• Improved PvP matchmaking to search a wider score range over time.
• The dungeon menu now retains the last selected tab and ranking list position.
• Your selected discard rarity is now remembered separately for items, pets, relics, and housing.
• Fixed issues with Blink, game speed, mount abilities, and dungeon lists.
We will continue improving the game for a more stable experience. 3.3.3 Jul 18 Improved public random matchmaking. If no match is found within 15 seconds, the search will expand to include players from other regions.
Improved friend room recovery. If the connection is lost after opening another app, the room will be restored automatically using the same room code.
Increased PvP score changes and adjusted how monster HP and movement speed scale over time.
Fixed various Co-op and PvP Dungeon issues involving the 10-Ton Weight, Hell Barrel, Chubby Shark’s anchor, Mysterious Cyclopean Portal, and tower information.
You can now select how many Hero / Tower Contracts to use when you own 100 or more.
Optimized memory usage to reduce crashes during gameplay. 3.3.2 Jul 13 Update Notes
- Fixed an issue where rewards might not be granted correctly or the game could become stuck on the results screen when playing normal stages or auto-play-supported content after using PvP mode.
- Fixed an issue where acquired items might not appear correctly on the results screen.
- Improved overall game stability. 3.3.1 Jul 11 The PvP event is now live!
Compete against other players in real-time PvP battles, climb the rankings, and earn score rewards.
This update also improves PvP stability, reward display, battle UI, and fixes various gameplay issues. 3.3.0 Jul 11 3.2.9 Update Notice
- Fixed multiplayer co-op so equipped heroes, towers, pets, and items now apply their actual levels and bonus options.
- Fixed an issue where the loadout shown in the Daily Co-op/Guild Co-op lobby could differ from the actual in-game loadout.
- Fixed a text issue where pet drop rate increase effects were shown as item drop rate increases on some screens.
We will keep improving the game for a more stable play experience. 3.2.9 Jul 8 - Improved co-op mode stability.
- Fixed some display issues.
- Fixed other bugs and improved overall stability. 3.2.8 Jul 6 This update includes a major overhaul of the multiplayer co-op experience.
We have reworked several co-op systems to improve the overall flow, stability, and long-term foundation of multiplayer play. Because this was a large change, we will continue monitoring reports closely and applying fixes as quickly as possible.
We also focused on in-game performance optimization to make battles feel smoother and more stable across more devices.
After recent server updates, some players experienced unexpected issues. We sincerely apologize for the inconvenience. We are continuing to review reports and logs carefully to prevent unfair losses and improve the overall service stability. 3.2.7 Jul 4 Version 3.2.6 Update
Samurai and Ninja have been improved.
Samurai’s [Target the Strong] boss bonus damage now applies as independent bonus damage. The Lv.9 wave-based attack bonus has been increased from 30% to 60%, and Crescent Slash now flies forward and pierces enemies. At Lv.12, Samurai now starts the game with 4 [Target the Strong] cards.
Ninja now deals 2x damage to monsters with 20% HP or less. Shuriken hits now apply Shadow Marks, increasing damage taken by marked enemies. The mark limit increases further at Lv.12, allowing much higher bonus damage.
Bingo and Board Game events can now run at the same time. You can select and play each event separately from the event screen.
Ranking league promotion has also been improved. Promotion steps now vary by rank, and the number of tiers gained is shown when promoted. 3.2.6 Jun 30 Applied recent server/account system fixes. Improved stability. 3.2.5 Jun 28 [Notice] Cloud Save Button Restored
Hello,
The 'Cloud Save' button that was temporarily disabled has now been fully restored.
You can use the Cloud Save feature normally again.
We sincerely apologize for any inconvenience and thank you for y 3.2.1 Jun 1 [UnderDark:Defense June Update]
- Reaper and Fat Shark heroes are newly revamped.
- Reaper’s minion system is improved.
- Fat Shark’s iron anchor ability is improved.
- Normal stages are expanded up to Stage 940.
- The Bingo event begins.
- Translation and item box related bugs are fixed.
- 1 additional support mercenary ability slot is added. 3.1.9 May 31 [UnderDark: Defense] May Update
- Balance improvements will be applied to Alien Spaceship and Joker characters.
- Alien Spaceship’s Black Hole and Laser abilities will be enhanced.
- Joker’s Card Stack and Surprise Box abilities will be improved.
- Auto option settings for items, mounts, pets, and relics will be added.
- Hero and tower stat calculation details will be improved.
- An issue with the oversized unlock icon in the Silkworm Moth Dungeon will be fixed. 3.1.8 May 21 [UnderDark: Defense] May Update
- A new hero, “Alien Spaceship,” has been added. (Equipped with Laser and Black Hole skills)
- The Joker hero has been revamped, improving attack mechanics and growth elements.
- Normal stages have been expanded up to 930, with new stages added.
- Events have been updated. (Board minigame begins / Bingo and Tower Pass end)
- Balance adjustments have been made to boomerang-type items.
- Some ranking translation errors have been fixed. 3.1.7 Apr 30 - Se corrigió un problema que mostraba el selector de cuentas de Google en cada inicio de sesión. 3.1.6 Apr 19 [Underdark: Defense] April 11 Update
- Guild capacity adjusted to 50 to match server limits and fix UI display issue
- Fixed an issue where weekly spending ranking currency changed abnormally
- Fixed an issue where Goblin Factory Tower was infinitely duplicated due to Imp Hero effect
- Fixed an issue where Sun Ring refresh option did not work properly
- Fixed an issue where buffs were skipped when refreshing after watching ads 3.1.5 Apr 10 This update from Apple will improve the functionality of this app. No new features are included.
[Underdark: Defense] April 1 Update
- Stages are expanded up to 920.
- The Season Pass will be updated.
- Living Tower growth missions are added.
- Living Tower heroes are buffed.
- The “Unexpected Companion Chicken” hero is buffed. 3.1.4 Mar 31 [Underdark: Defense] Update
- Added 4 new towers
- Added new ranking dungeon “Silkworm Moth”
- Added new limited tower pass
- Reduced difficulty of Co-op Dungeon 1
- Fixed an issue where the Buff Reset +1 option did not stack 3.1.3 Mar 22 [Underdark: Defense] March 14 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.2 Mar 14 [Underdark: Defense] March 13 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.1 Mar 12 Fixed an issue where the weekly ranking currency changed at the wrong time.
The weekly ranking currency has been changed back to Diamonds. 3.1.0 Mar 7 Fixed an issue with claiming Weekly Currency Ranking rewards. 3.0.9 Mar 5
Underdark:Defense version 3.3.3
Updated At: 2026-07-24
Changes: Version History This update improves PvP matchmaking and convenience features while addressing several issues.
• Improved PvP matchmaking to search a wider score range over time.
• The dungeon menu now retains the last selected tab and ranking list position.
• Your selected discard rarity is now remembered separately for items, pets, relics, and housing.
• Fixed issues with Blink, game speed, mount abilities, and dungeon lists.
We will continue improving the game for a more stable experience. 3.3.3 6d ago Improved public random matchmaking. If no match is found within 15 seconds, the search will expand to include players from other regions.
Improved friend room recovery. If the connection is lost after opening another app, the room will be restored automatically using the same room code.
Increased PvP score changes and adjusted how monster HP and movement speed scale over time.
Fixed various Co-op and PvP Dungeon issues involving the 10-Ton Weight, Hell Barrel, Chubby Shark’s anchor, Mysterious Cyclopean Portal, and tower information.
You can now select how many Hero / Tower Contracts to use when you own 100 or more.
Optimized memory usage to reduce crashes during gameplay. 3.3.2 Jul 13 Update Notes
- Fixed an issue where rewards might not be granted correctly or the game could become stuck on the results screen when playing normal stages or auto-play-supported content after using PvP mode.
- Fixed an issue where acquired items might not appear correctly on the results screen.
- Improved overall game stability. 3.3.1 Jul 11 The PvP event is now live!
Compete against other players in real-time PvP battles, climb the rankings, and earn score rewards.
This update also improves PvP stability, reward display, battle UI, and fixes various gameplay issues. 3.3.0 Jul 11 3.2.9 Update Notice
- Fixed multiplayer co-op so equipped heroes, towers, pets, and items now apply their actual levels and bonus options.
- Fixed an issue where the loadout shown in the Daily Co-op/Guild Co-op lobby could differ from the actual in-game loadout.
- Fixed a text issue where pet drop rate increase effects were shown as item drop rate increases on some screens.
We will keep improving the game for a more stable play experience. 3.2.9 Jul 8 - Improved co-op mode stability.
- Fixed some display issues.
- Fixed other bugs and improved overall stability. 3.2.8 Jul 6 This update includes a major overhaul of the multiplayer co-op experience.
We have reworked several co-op systems to improve the overall flow, stability, and long-term foundation of multiplayer play. Because this was a large change, we will continue monitoring reports closely and applying fixes as quickly as possible.
We also focused on in-game performance optimization to make battles feel smoother and more stable across more devices.
After recent server updates, some players experienced unexpected issues. We sincerely apologize for the inconvenience. We are continuing to review reports and logs carefully to prevent unfair losses and improve the overall service stability. 3.2.7 Jul 4 Version 3.2.6 Update
Samurai and Ninja have been improved.
Samurai’s [Target the Strong] boss bonus damage now applies as independent bonus damage. The Lv.9 wave-based attack bonus has been increased from 30% to 60%, and Crescent Slash now flies forward and pierces enemies. At Lv.12, Samurai now starts the game with 4 [Target the Strong] cards.
Ninja now deals 2x damage to monsters with 20% HP or less. Shuriken hits now apply Shadow Marks, increasing damage taken by marked enemies. The mark limit increases further at Lv.12, allowing much higher bonus damage.
Bingo and Board Game events can now run at the same time. You can select and play each event separately from the event screen.
Ranking league promotion has also been improved. Promotion steps now vary by rank, and the number of tiers gained is shown when promoted. 3.2.6 Jun 30 Applied recent server/account system fixes. Improved stability. 3.2.5 Jun 28 [Notice] Cloud Save Button Restored
Hello,
The 'Cloud Save' button that was temporarily disabled has now been fully restored.
You can use the Cloud Save feature normally again.
We sincerely apologize for any inconvenience and thank you for y 3.2.1 Jun 1 [UnderDark:Defense June Update]
- Reaper and Fat Shark heroes are newly revamped.
- Reaper’s minion system is improved.
- Fat Shark’s iron anchor ability is improved.
- Normal stages are expanded up to Stage 940.
- The Bingo event begins.
- Translation and item box related bugs are fixed.
- 1 additional support mercenary ability slot is added. 3.1.9 May 31 [UnderDark: Defense] May Update
- Balance improvements will be applied to Alien Spaceship and Joker characters.
- Alien Spaceship’s Black Hole and Laser abilities will be enhanced.
- Joker’s Card Stack and Surprise Box abilities will be improved.
- Auto option settings for items, mounts, pets, and relics will be added.
- Hero and tower stat calculation details will be improved.
- An issue with the oversized unlock icon in the Silkworm Moth Dungeon will be fixed. 3.1.8 May 21 [UnderDark: Defense] May Update
- A new hero, “Alien Spaceship,” has been added. (Equipped with Laser and Black Hole skills)
- The Joker hero has been revamped, improving attack mechanics and growth elements.
- Normal stages have been expanded up to 930, with new stages added.
- Events have been updated. (Board minigame begins / Bingo and Tower Pass end)
- Balance adjustments have been made to boomerang-type items.
- Some ranking translation errors have been fixed. 3.1.7 Apr 30 - Se corrigió un problema que mostraba el selector de cuentas de Google en cada inicio de sesión. 3.1.6 Apr 19 [Underdark: Defense] April 11 Update
- Guild capacity adjusted to 50 to match server limits and fix UI display issue
- Fixed an issue where weekly spending ranking currency changed abnormally
- Fixed an issue where Goblin Factory Tower was infinitely duplicated due to Imp Hero effect
- Fixed an issue where Sun Ring refresh option did not work properly
- Fixed an issue where buffs were skipped when refreshing after watching ads 3.1.5 Apr 10 This update from Apple will improve the functionality of this app. No new features are included.
[Underdark: Defense] April 1 Update
- Stages are expanded up to 920.
- The Season Pass will be updated.
- Living Tower growth missions are added.
- Living Tower heroes are buffed.
- The “Unexpected Companion Chicken” hero is buffed. 3.1.4 Mar 31 [Underdark: Defense] Update
- Added 4 new towers
- Added new ranking dungeon “Silkworm Moth”
- Added new limited tower pass
- Reduced difficulty of Co-op Dungeon 1
- Fixed an issue where the Buff Reset +1 option did not stack 3.1.3 Mar 22 [Underdark: Defense] March 14 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.2 Mar 14 [Underdark: Defense] March 13 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.1 Mar 12 Fixed an issue where the weekly ranking currency changed at the wrong time.
The weekly ranking currency has been changed back to Diamonds. 3.1.0 Mar 7 Fixed an issue with claiming Weekly Currency Ranking rewards. 3.0.9 Mar 5 [Underdark Defense] March 1 Update
- The Mysterious Armor hero will be remade.
- The Mischievous Devil hero will be remade.
- Stages will be expanded up to 910.
- A Weekly Spending Ranking system will be introduced.
- Co-op Mode stability will be improved. 3.0.8 Feb 28 [Update Details – February 2]
Bug Fixes & Improvements
- Fixed an issue in Daily Dungeon Multiplayer mode where some players could not press the entry button or the UI was not displayed correctly.
- Fixed an issue where the Daily Dungeon Multiplayer ranking UI was displayed incorrectly.
- Fixed an attack speed–related issue occurring in Daily Dungeon Multiplayer mode.
- Balance adjustment: Gamblewood has been nerfed.
- Gamblewood Lv.6 ability has been adjusted. (Max 2000% → 500%) 3.0.7 Feb 2 [Update Details – February 1]
Hero Improvements
- Hero Gamblewood has been revamped!
- Hero Thor has been strengthened!
New Dungeon and Special Notes
- Normal stages have been expanded up to Stage 900.
- 10 new stages have been added.
- A multiplayer mode has been added to the Daily Dungeon.
Events
- The Bingo Mini-Game begins on February 1 (KST).
- The 2026 Event ends on January 31 (KST).
- The Board Mini-Game ends on January 31 (KST).
Bug Fixes and Improvements
- Fixed an issue related to guild levels.
- Improvements have been made to pet summons. 3.0.6 Jan 31 [Update Details – January 1]
New Hero
- The Nine-Tailed Fox joins Underdark!
- Defeat enemies together with the charming Nine-Tailed Fox!
New Stages and Special Notes
- Normal stages have been expanded up to Stage 890.
- 10 new stages have been added.
Events
- The 2026 New Year Event begins on January 1 (KST).
- The Board Mini-Game begins on January 1 (KST).
- The Bingo Event ends on December 31 (KST).
Bug Fixes and Improvements
- Lava Golem optimization has been applied.
- Lava Golem’s Fireball damage and movement speed have been increased.
- A Curse Tower tutorial has been added to Stage 21. 3.0.4 12/31/2025
Underdark:Defense version 3.2.8
Updated At: 2026-07-06
Changes: Version History - Improved co-op mode stability.
- Fixed some display issues.
- Fixed other bugs and improved overall stability. 3.2.8 13h ago This update includes a major overhaul of the multiplayer co-op experience.
We have reworked several co-op systems to improve the overall flow, stability, and long-term foundation of multiplayer play. Because this was a large change, we will continue monitoring reports closely and applying fixes as quickly as possible.
We also focused on in-game performance optimization to make battles feel smoother and more stable across more devices.
After recent server updates, some players experienced unexpected issues. We sincerely apologize for the inconvenience. We are continuing to review reports and logs carefully to prevent unfair losses and improve the overall service stability. 3.2.7 2d ago Version 3.2.6 Update
Samurai and Ninja have been improved.
Samurai’s [Target the Strong] boss bonus damage now applies as independent bonus damage. The Lv.9 wave-based attack bonus has been increased from 30% to 60%, and Crescent Slash now flies forward and pierces enemies. At Lv.12, Samurai now starts the game with 4 [Target the Strong] cards.
Ninja now deals 2x damage to monsters with 20% HP or less. Shuriken hits now apply Shadow Marks, increasing damage taken by marked enemies. The mark limit increases further at Lv.12, allowing much higher bonus damage.
Bingo and Board Game events can now run at the same time. You can select and play each event separately from the event screen.
Ranking league promotion has also been improved. Promotion steps now vary by rank, and the number of tiers gained is shown when promoted. 3.2.6 5d ago Applied recent server/account system fixes. Improved stability. 3.2.5 Jun 28 [Notice] Cloud Save Button Restored
Hello,
The 'Cloud Save' button that was temporarily disabled has now been fully restored.
You can use the Cloud Save feature normally again.
We sincerely apologize for any inconvenience and thank you for y 3.2.1 Jun 1 [UnderDark:Defense June Update]
- Reaper and Fat Shark heroes are newly revamped.
- Reaper’s minion system is improved.
- Fat Shark’s iron anchor ability is improved.
- Normal stages are expanded up to Stage 940.
- The Bingo event begins.
- Translation and item box related bugs are fixed.
- 1 additional support mercenary ability slot is added. 3.1.9 May 31 [UnderDark: Defense] May Update
- Balance improvements will be applied to Alien Spaceship and Joker characters.
- Alien Spaceship’s Black Hole and Laser abilities will be enhanced.
- Joker’s Card Stack and Surprise Box abilities will be improved.
- Auto option settings for items, mounts, pets, and relics will be added.
- Hero and tower stat calculation details will be improved.
- An issue with the oversized unlock icon in the Silkworm Moth Dungeon will be fixed. 3.1.8 May 21 [UnderDark: Defense] May Update
- A new hero, “Alien Spaceship,” has been added. (Equipped with Laser and Black Hole skills)
- The Joker hero has been revamped, improving attack mechanics and growth elements.
- Normal stages have been expanded up to 930, with new stages added.
- Events have been updated. (Board minigame begins / Bingo and Tower Pass end)
- Balance adjustments have been made to boomerang-type items.
- Some ranking translation errors have been fixed. 3.1.7 Apr 30 - Se corrigió un problema que mostraba el selector de cuentas de Google en cada inicio de sesión. 3.1.6 Apr 19 [Underdark: Defense] April 11 Update
- Guild capacity adjusted to 50 to match server limits and fix UI display issue
- Fixed an issue where weekly spending ranking currency changed abnormally
- Fixed an issue where Goblin Factory Tower was infinitely duplicated due to Imp Hero effect
- Fixed an issue where Sun Ring refresh option did not work properly
- Fixed an issue where buffs were skipped when refreshing after watching ads 3.1.5 Apr 10 This update from Apple will improve the functionality of this app. No new features are included.
[Underdark: Defense] April 1 Update
- Stages are expanded up to 920.
- The Season Pass will be updated.
- Living Tower growth missions are added.
- Living Tower heroes are buffed.
- The “Unexpected Companion Chicken” hero is buffed. 3.1.4 Mar 31 [Underdark: Defense] Update
- Added 4 new towers
- Added new ranking dungeon “Silkworm Moth”
- Added new limited tower pass
- Reduced difficulty of Co-op Dungeon 1
- Fixed an issue where the Buff Reset +1 option did not stack 3.1.3 Mar 22 [Underdark: Defense] March 14 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.2 Mar 14 [Underdark: Defense] March 13 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.1 Mar 12 Fixed an issue where the weekly ranking currency changed at the wrong time.
The weekly ranking currency has been changed back to Diamonds. 3.1.0 Mar 7 Fixed an issue with claiming Weekly Currency Ranking rewards. 3.0.9 Mar 5 [Underdark Defense] March 1 Update
- The Mysterious Armor hero will be remade.
- The Mischievous Devil hero will be remade.
- Stages will be expanded up to 910.
- A Weekly Spending Ranking system will be introduced.
- Co-op Mode stability will be improved. 3.0.8 Feb 28 [Update Details – February 2]
Bug Fixes & Improvements
- Fixed an issue in Daily Dungeon Multiplayer mode where some players could not press the entry button or the UI was not displayed correctly.
- Fixed an issue where the Daily Dungeon Multiplayer ranking UI was displayed incorrectly.
- Fixed an attack speed–related issue occurring in Daily Dungeon Multiplayer mode.
- Balance adjustment: Gamblewood has been nerfed.
- Gamblewood Lv.6 ability has been adjusted. (Max 2000% → 500%) 3.0.7 Feb 2 [Update Details – February 1]
Hero Improvements
- Hero Gamblewood has been revamped!
- Hero Thor has been strengthened!
New Dungeon and Special Notes
- Normal stages have been expanded up to Stage 900.
- 10 new stages have been added.
- A multiplayer mode has been added to the Daily Dungeon.
Events
- The Bingo Mini-Game begins on February 1 (KST).
- The 2026 Event ends on January 31 (KST).
- The Board Mini-Game ends on January 31 (KST).
Bug Fixes and Improvements
- Fixed an issue related to guild levels.
- Improvements have been made to pet summons. 3.0.6 Jan 31 [Update Details – January 1]
New Hero
- The Nine-Tailed Fox joins Underdark!
- Defeat enemies together with the charming Nine-Tailed Fox!
New Stages and Special Notes
- Normal stages have been expanded up to Stage 890.
- 10 new stages have been added.
Events
- The 2026 New Year Event begins on January 1 (KST).
- The Board Mini-Game begins on January 1 (KST).
- The Bingo Event ends on December 31 (KST).
Bug Fixes and Improvements
- Lava Golem optimization has been applied.
- Lava Golem’s Fireball damage and movement speed have been increased.
- A Curse Tower tutorial has been added to Stage 21. 3.0.4 12/31/2025 [Update Details]
Bug Fixes and Improvements
- The issue where the ranking dungeon disappears will be fixed. 3.0.3 12/10/2025 [Update Details]
Bug Fixes and Improvements
- The existing co-op dungeon will be added again.
- An issue where the in-game scrollbar range becomes narrow will be fixed.
- An issue where the Battery Tower was not affected by the Wind Boomerang will be fixed.
- An issue where obstacles were displayed abnormally in Zombie Penguin Village will be fixed. 3.0.2 12/02/2025 [Update Notes – December 1]
New Hero
- The Lava Golem joins the Underdark!
- Melt your enemies with powerful Meteors and Fireballs!
New Stage & Special Features
- A new stage will be added.
- A new co-op mode will be added.
Events
- The Board Game mini-event ends on November 30 (KST).
- The Halloween event ends on November 30 (KST).
- The Bingo event begins on December 1 (KST).
Bug Fixes & Improvements
- Fixed an issue where the “End of War” display appeared abnormally.
- Expanded the maximum item level.
- Added a support mercenary slot.
- Added a feature that allows faster growth selection. 3.0.1 11/30/2025 [Update Notes – November 1]
New Hero
- Succubus joins the Underdark!
- Defeat monsters through the alluring mist of the Succubus!
Hero Improvements
- Fat Shark’s level 3 ability has been enhanced.
- Plague Doctor’s level 12 ability has been enhanced.
New Stage & Features
- A new stage will be added.
- Account level cap expanded to 300.
- Daily Dungeon hero levels will now randomly vary between levels 1 and 12.
Events
- The Bingo Event ends on October 31 (KST)!
- The Board Event begins on November 1 (KST)!
- The Halloween Event begins on November 1 (KST)!
Bug Fixes & Improvements
- Fixed an issue where the game would close abnormally in certain dungeons.
- Fixed an issue where the account level increased abnormally in the level 241 range.
- Fixed an issue where Valkyrie’s support mercenary effect was not applied when auto-equipping weapons.
- The abilities of Guild Dungeon 1 Boss and Medusa Boss have been reduced.
- The item draw limit has been increased to 2000. 3.0.0 10/31/2025 Fixed an issue where Stage 851 could not be progressed
Fixed an issue where the Cheerful Pirate Shark skin could not attack
Corrected the display error in Battlefield of Doom
Fixed an issue where Anubis’s Mark was incorrectly displayed on certain units 2.9.9 10/04/2025
Underdark:Defense version 3.2.5
Updated At: 2026-06-29
Changes: Version History Applied recent server/account system fixes. Improved stability. 3.2.5 11h ago [Notice] Cloud Save Button Restored
Hello,
The 'Cloud Save' button that was temporarily disabled has now been fully restored.
You can use the Cloud Save feature normally again.
We sincerely apologize for any inconvenience and thank you for y 3.2.1 Jun 1 [UnderDark:Defense June Update]
- Reaper and Fat Shark heroes are newly revamped.
- Reaper’s minion system is improved.
- Fat Shark’s iron anchor ability is improved.
- Normal stages are expanded up to Stage 940.
- The Bingo event begins.
- Translation and item box related bugs are fixed.
- 1 additional support mercenary ability slot is added. 3.1.9 May 31 [UnderDark: Defense] May Update
- Balance improvements will be applied to Alien Spaceship and Joker characters.
- Alien Spaceship’s Black Hole and Laser abilities will be enhanced.
- Joker’s Card Stack and Surprise Box abilities will be improved.
- Auto option settings for items, mounts, pets, and relics will be added.
- Hero and tower stat calculation details will be improved.
- An issue with the oversized unlock icon in the Silkworm Moth Dungeon will be fixed. 3.1.8 May 21 [UnderDark: Defense] May Update
- A new hero, “Alien Spaceship,” has been added. (Equipped with Laser and Black Hole skills)
- The Joker hero has been revamped, improving attack mechanics and growth elements.
- Normal stages have been expanded up to 930, with new stages added.
- Events have been updated. (Board minigame begins / Bingo and Tower Pass end)
- Balance adjustments have been made to boomerang-type items.
- Some ranking translation errors have been fixed. 3.1.7 Apr 30 - Se corrigió un problema que mostraba el selector de cuentas de Google en cada inicio de sesión. 3.1.6 Apr 19 [Underdark: Defense] April 11 Update
- Guild capacity adjusted to 50 to match server limits and fix UI display issue
- Fixed an issue where weekly spending ranking currency changed abnormally
- Fixed an issue where Goblin Factory Tower was infinitely duplicated due to Imp Hero effect
- Fixed an issue where Sun Ring refresh option did not work properly
- Fixed an issue where buffs were skipped when refreshing after watching ads 3.1.5 Apr 10 This update from Apple will improve the functionality of this app. No new features are included.
[Underdark: Defense] April 1 Update
- Stages are expanded up to 920.
- The Season Pass will be updated.
- Living Tower growth missions are added.
- Living Tower heroes are buffed.
- The “Unexpected Companion Chicken” hero is buffed. 3.1.4 Mar 31 [Underdark: Defense] Update
- Added 4 new towers
- Added new ranking dungeon “Silkworm Moth”
- Added new limited tower pass
- Reduced difficulty of Co-op Dungeon 1
- Fixed an issue where the Buff Reset +1 option did not stack 3.1.3 Mar 22 [Underdark: Defense] March 14 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.2 Mar 14 [Underdark: Defense] March 13 Update
- New content Guild 4-player co-op dungeon added
- New items 2 helmets and 2 rings added
- Guest accounts are excluded from the Top 10 ranking
- Spending ranking closing time adjusted to every Sunday 23:50 (KST)
- In the spending ranking, guest accounts will start being counted after linking a Google or Apple account 3.1.1 Mar 12 Fixed an issue where the weekly ranking currency changed at the wrong time.
The weekly ranking currency has been changed back to Diamonds. 3.1.0 Mar 7 Fixed an issue with claiming Weekly Currency Ranking rewards. 3.0.9 Mar 5 [Underdark Defense] March 1 Update
- The Mysterious Armor hero will be remade.
- The Mischievous Devil hero will be remade.
- Stages will be expanded up to 910.
- A Weekly Spending Ranking system will be introduced.
- Co-op Mode stability will be improved. 3.0.8 Feb 28 [Update Details – February 2]
Bug Fixes & Improvements
- Fixed an issue in Daily Dungeon Multiplayer mode where some players could not press the entry button or the UI was not displayed correctly.
- Fixed an issue where the Daily Dungeon Multiplayer ranking UI was displayed incorrectly.
- Fixed an attack speed–related issue occurring in Daily Dungeon Multiplayer mode.
- Balance adjustment: Gamblewood has been nerfed.
- Gamblewood Lv.6 ability has been adjusted. (Max 2000% → 500%) 3.0.7 Feb 2 [Update Details – February 1]
Hero Improvements
- Hero Gamblewood has been revamped!
- Hero Thor has been strengthened!
New Dungeon and Special Notes
- Normal stages have been expanded up to Stage 900.
- 10 new stages have been added.
- A multiplayer mode has been added to the Daily Dungeon.
Events
- The Bingo Mini-Game begins on February 1 (KST).
- The 2026 Event ends on January 31 (KST).
- The Board Mini-Game ends on January 31 (KST).
Bug Fixes and Improvements
- Fixed an issue related to guild levels.
- Improvements have been made to pet summons. 3.0.6 Jan 31 [Update Details – January 1]
New Hero
- The Nine-Tailed Fox joins Underdark!
- Defeat enemies together with the charming Nine-Tailed Fox!
New Stages and Special Notes
- Normal stages have been expanded up to Stage 890.
- 10 new stages have been added.
Events
- The 2026 New Year Event begins on January 1 (KST).
- The Board Mini-Game begins on January 1 (KST).
- The Bingo Event ends on December 31 (KST).
Bug Fixes and Improvements
- Lava Golem optimization has been applied.
- Lava Golem’s Fireball damage and movement speed have been increased.
- A Curse Tower tutorial has been added to Stage 21. 3.0.4 12/31/2025 [Update Details]
Bug Fixes and Improvements
- The issue where the ranking dungeon disappears will be fixed. 3.0.3 12/10/2025 [Update Details]
Bug Fixes and Improvements
- The existing co-op dungeon will be added again.
- An issue where the in-game scrollbar range becomes narrow will be fixed.
- An issue where the Battery Tower was not affected by the Wind Boomerang will be fixed.
- An issue where obstacles were displayed abnormally in Zombie Penguin Village will be fixed. 3.0.2 12/02/2025 [Update Notes – December 1]
New Hero
- The Lava Golem joins the Underdark!
- Melt your enemies with powerful Meteors and Fireballs!
New Stage & Special Features
- A new stage will be added.
- A new co-op mode will be added.
Events
- The Board Game mini-event ends on November 30 (KST).
- The Halloween event ends on November 30 (KST).
- The Bingo event begins on December 1 (KST).
Bug Fixes & Improvements
- Fixed an issue where the “End of War” display appeared abnormally.
- Expanded the maximum item level.
- Added a support mercenary slot.
- Added a feature that allows faster growth selection. 3.0.1 11/30/2025 [Update Notes – November 1]
New Hero
- Succubus joins the Underdark!
- Defeat monsters through the alluring mist of the Succubus!
Hero Improvements
- Fat Shark’s level 3 ability has been enhanced.
- Plague Doctor’s level 12 ability has been enhanced.
New Stage & Features
- A new stage will be added.
- Account level cap expanded to 300.
- Daily Dungeon hero levels will now randomly vary between levels 1 and 12.
Events
- The Bingo Event ends on October 31 (KST)!
- The Board Event begins on November 1 (KST)!
- The Halloween Event begins on November 1 (KST)!
Bug Fixes & Improvements
- Fixed an issue where the game would close abnormally in certain dungeons.
- Fixed an issue where the account level increased abnormally in the level 241 range.
- Fixed an issue where Valkyrie’s support mercenary effect was not applied when auto-equipping weapons.
- The abilities of Guild Dungeon 1 Boss and Medusa Boss have been reduced.
- The item draw limit has been increased to 2000. 3.0.0 10/31/2025 Fixed an issue where Stage 851 could not be progressed
Fixed an issue where the Cheerful Pirate Shark skin could not attack
Corrected the display error in Battlefield of Doom
Fixed an issue where Anubis’s Mark was incorrectly displayed on certain units 2.9.9 10/04/2025 [Update – October 1]
New Hero
- Anubis joins the Underdark!
- Sweep through dungeons with the ancient hero Anubis!
New Pass
- 6 new Hero Passes will be added.
New Stage
- New stages will be added.
Event
- The Board Game mini-event will end on September 30 (KST).
- The Bingo Event will begin on October 1 (KST).
Bug Fixes and Improvements
- The Apocalypse Battlefield ranking will be reset.
- The Apocalypse Battlefield ranking calculation will change from cumulative damage to a point-based system.
- Fixed an issue where the Relic of Immunity in Guild Dungeon 1 would not deactivate.
- Fixed the shark appearance of the Cheerful Pirate skin.
- Fixed an issue where some pets were not being pushed back by heroes. 2.9.8 09/30/2025 [Underdark: Defense]
- Fixed an issue where the chat function was not working properly.
- Fixed an issue where the full immunity debuff in guild dungeons was not deactivated.
- Fixed an issue where heroes appeared abnormally while moving on top of the tower.
- Fixed an issue where heroes on top of the tower did not receive various buff effects. 2.9.7 09/08/2025 [Update Notes – September 1]
Bug Fixes and Improvements
- Fixed text error for Valkyrie support mercenary.
- Added sounds for Valkyrie and the new tower.
- The swords around Valkyrie now apply knockback effect to monsters.
- Fixed an issue where some character data was lost due to co-op mode. 2.9.6 09/01/2025
