01 STRONGHOLD PROTOCOL: ALLIANCE OPEN DURATION: August 20, 2026, 09:00 – October 1, 2026, 03:59 (UTC-7) UNLOCK REQUIREMENT: Clear Main Storyline 1-10 DETAILS: During the event, players can obtain event rewards by leveling up [Stronghold Credit] with [Stronghold Credits], which can be earned by clearing event stages, completing [Key Objectives] missions and Daily Goal; In addition, this update improves the experience of Solo Simulation and Team Simulation, while also introducing new difficulties, Alliances, Strategies, and more. [Stronghold Credit] DURATION: August 20, 2026, 09:00 – October 4, 2026, 03:59 (UTC-7) REWARDS: MARTHE Sports Line - Hydration Time for Mousse, Event Icon 'Restarting Simulation!', Module Materials, Elite Materials, Battle Records, LMD, etc. [Main Updates] - Solo Simulation optimization: Rest Phases and Improv Phases are no longer time-limited; you may leave partway through and return within 24 hours to continue the simulation. In addition, the Round Count required for Standard Simulations has been reduced. - Team Simulation optimization: You can now start simulations with fewer than 4 players. The unlock states of Simulation are now shared between Solo Simulation and Team Simulation, and a new higher difficulty level, [Ultimate Simulation], has been added. - Preset Operator optimization: All 4★, 5★, and event-gifted 6★ Operators can now be used directly, even if not owned. - Interaction optimization: Equipment can now be equipped directly to Operators on the Bench, and Operators on the Bench and in the Battle Zone can be swapped even when the Bench is full. - Combat optimization: The mechanics of certain enemy leaders have been adjusted, and the ATK of some enemies has been reduced. In addition, this update will introduce new Alliances, Strategies, Preset Operators, Equipment, maps, and enemies, along with balance adjustments to some existing content. NOTE: - Daily Goal: Players can obtain [Stronghold Credits] every day through Simulation. Once reached a certain amount, a bonus [Stronghold Credits] reward will be available at the completion screen. This reward can be claimed once per day, refreshing daily at 04:00 (UTC-7). - Some Rerun Outfits will return to the Outfit Store from August 20, 08:00 to September 10, 03:59 (UTC-7). Please refer to the in-game Outfit Store for details. 02 TARGETED OPERATOR HEADHUNTING OPEN: JOINT OPERATION D URATION: August 20, 2026, 09:00 – September 3, 2026, 03:59 (UTC-7) DETAILS: During the event, the Targeted Operator Headhunting, [Joint Operation], opens, and ONLY the following Operators will appear in the 6★ and 5★ Operator List of this Standard Headhunting: ★★★★★★: Mantra / Ulpianus / Narantuya / Reed the Flame Shadow ★★★★★: Grain Buds / Harmonie / Tippi / Cantabile / Figurino / Cairn Note: This is a [Standard Headhunting]. 03 LIMITED-TIME PACKS AVAILABLE DETAILS: During the event, the following packs will be available from the Store for a limited time. Stronghold Protocol Data Pack DURATION: August 20, 2026, 09:00 – September 10, 2026, 03:59 (UTC-7) CONTENTS: Module Data Block * 12 Stronghold Protocol Data Set DURATION: August 20, 2026, 09:00 – September 10, 2026, 03:59 (UTC-7) CONTENTS: Module Data Block * 24, Data Supplement Instrument * 30, Data Supplement Stick * 90 Echoes of the Legends Pack DURATION: August 20, 2026, 09:00 – September 3, 2026, 03:59 (UTC-7) CONTENTS: 
Orundum * 1600, Profile Theme 'Echoes of the Legends' * 1 ◆ This Profile Theme can be switched among different characters: Sora, Exusiai, Emperor, Croissant, and Texas. Divine Reverie Pack DURATION: August 20, 2026, 09:00 – September 3, 2026, 03:59 (UTC-7) CONTENTS: Orundum * 1600, Profile Theme 'Divine Reverie' * 1 ◆ This Profile Theme can be switched among different Operators: Ebenholz, Logos, Muelsyse, Silence the Paradigmatic, and Surtr. Glazed Grace Pack DURATION: August 20, 2026, 08:00 – September 3, 2026, 03:59 (UTC-7) CONTENTS: Orundum * 1600, Profile Theme 'Glazed Grace' * 1 ◆ This Profile Theme can be switched among different Operators: Angelina, Shu, Ch'en, Zuo Le, and Blaze. The Wild Era Pack DURATION: August 20, 2026, 09:00 – September 3, 2026, 03:59 (UTC-7) CONTENTS: Orundum * 1600, Profile Theme 'The Wild Era' * 1 ◆ This Profile Theme can be switched among different Operators: Lappland the Decadenza, La Pluma, Thorns, Vulpisfoglia, and Mostima. Blooms of Time Pack DURATION: August 20, 2026, 09:00 – September 3, 2026, 03:59 (UTC-7) CONTENTS: Orundum * 1600, Profile Theme 'Blooms of Time' * 1 ◆ This Profile Theme can be switched among different Operators: Elysium, Nymph, Amiya, Specter the Unchained, and Rosmontis. Please stay tuned for more information!
Arknights · Update notes
Stronghold Protocol and Joint Operation
01 STRONGHOLD PROTOCOL: ALLIANCE OPEN DURATION: August 20, 2026, 09:00 – October 1, 2026, 03:59 (UTC-7) UNLOCK REQUIREMENT: Clear Main Storyline 1-10 DETAILS: During the event, players can obtain event rewards by leveling up [Stronghold Credit] with [Stronghold Credits], which can be earned by clearing event stag
Notice↗
Featured rewards
Notice details
Stronghold Protocol ran August 20, 09:00–October 1, 03:59 UTC−7, with reward claims until October 4 and a 1-10 prerequisite.
Stages, key missions and daily goals earned credits for Mousse’s outfit, an icon and materials.
The extra daily credit reward was claimable once per day, resetting at 04:00.
Mode changes, recruitment and sales
Solo mode removed rest/improv timers and allowed resuming within 24 hours.
Co-op could start below four players, shared unlocks with solo and gained a harder difficulty.
Unowned 4★, 5★ and event-gifted 6★ presets became usable; bench equipping/swapping improved.
Joint Operation featured only its listed 6★/5★ units through September 3.
Module packs sold 12 or 24 blocks plus supplemental items through September 10.