Operator Modules, or simply Modules, are a feature in Arknights, introduced alongside class branches in Dossoles Holiday.
Only available for 4★ and above Operators, Modules are a special item that acts as an "equipment" which improves their attributes and either upgrades their trait or adding a new trait when equipped, improving the Operator's performance particularly in their primary roles. All Modules (except the default Badges) are unique to each Operator and cannot be equipped by the others, even those in the same class, branch, or rarity.
Modules are initially not available and must be unlocked by using 
Module Data Block, upgrade materials, and 
LMD once the player completes certain tasks termed Module Missions and by raising the corresponding Operator's promotion, level, and Trust to a specific threshold.
Since the Lingering Echoes update, Modules can be upgraded through two additional stages to improve the corresponding Operator's talent or add a new talent, and enhance its attribute improvements at the cost of more Module Data Blocks, upgrade materials, and LMDs, as well as a large amount of 
Data Supplement Stick for the second stage and 
Data Supplement Instrument for the third stage.
List[]
The following is a list of class branches with available Modules including their effects and which Operators have them as of September 5, 2023, sorted alphabetically by their branch name and introduction date.
| Branch | Module | Description |
|---|---|---|
|
 CHA-X
|
Reduces the damage loss in each jump to 10% and increases the slow duration of each hit to 0.8 seconds (the same as Decel Binder Supporters). Introduced in: Near Light
|
 CHA-Y
|
Removes the damage loss in each jump. Introduced in: Near Light
| |
|
 SPC-X
|
Extends the Splash Caster's attack range to 3×3 tiles with a 1-tile extension up front. Introduced in: Guide Ahead
|
 SPC-Y
|
Reduces the Splash Caster's DP cost by 8. Introduced in: Guide Ahead
| |
|
 MSC-X
|
The Mystic Caster can store one additional attack. Introduced in: Lingering Echoes
|
 MSC-Y
|
When the Mystic Caster stores at least one attack, their ASPD is increased by 30. Introduced in: An Obscure Wanderer
| |
|
 CCR-X
|
The Core Caster's attacks ignore 10 RES. Introduced in: Where Vernal Winds Will Never Blow
|
 CCR-Y
|
The Core Caster generates 1 SP when attacking elite or boss enemies. Introduced in: Where Vernal Winds Will Never Blow
| |
|
 BLA-X
|
The Blast Caster's ATK is increased when attacking targets further away from their position, which caps at 10%. Introduced in: A Flurry to the Flame
|
|
 PLX-X
|
The DEF and RES buff while the skill is not active is increased to 215% and 25, respectively. When the Phalanx Caster's skill is active, their DEF and RES are increased by 100 and 10, respectively. Introduced in: [CN] Episode 12: All Quiet Under the Thunder
|
| Branch | Module | Description |
|---|---|---|
|
 HES-X
|
The Duelist Defender generates 0.2 SP every second when not blocking enemies. Introduced in: Stultifera Navis
|
 HES-Y
|
The Duelist Defender can now receive SP from other sources (e.g. Liskarm's Tactical Defense). When the Duelist is blocking enemies, their ATK and DEF are increased by 15%. Introduced in: An Obscure Wanderer
| |
|
 GUA-X
|
When the Guardian Defender heals friendly units whose HP had fallen below 50%, the healing amount is increased by 15%. Introduced in: Lingering Echoes
|
 GUA-Y
|
The Guardian Defender takes 15% less damage. Introduced in: Lingering Echoes
| |
|
 PRO-X
|
When the Protector Defender is blocking enemies, their DEF is increased by 20%. Introduced in: An Obscure Wanderer
|
 PRO-Y
|
The Protector Defender can block four enemies on their own. Introduced in: An Obscure Wanderer
|
| Branch | Module | Description |
|---|---|---|
|
 INS-X
|
The damage dealt by the Instructor Guard when attacking enemies they are not blocking is further increased to 130%. Introduced in: Dossoles Holiday
|
 INS-Y
|
The Instructor Guard can now be deployed in both melee and ranged tiles. Introduced in: Dossoles Holiday
| |
|
 SWO-X
|
The Swordmaster Guard's skills deal 10% more damage. Introduced in: Break the Ice
|
 SWO-Y
|
The Swordmaster Guard's attacks ignore 70 DEF. Introduced in: Break the Ice
| |
|
 DRE-X
|
When the Dreadnought Guard attack enemies that are being blocked, their ATK is increased to 115%. Introduced in: Invitation to Wine
|
 DRE-Y
|
When the Dreadnought Guard's HP is reduced to 0, they will survive with their HP fully restored and ASPD increased by 30, but their maximum HP is reduced by 60%. This effect can only be triggered once per deployment. Introduced in: Invitation to Wine
| |
|
 MUS-X
|
When the Musha Guard's HP falls below 50%, they receive a 25% Sanctuary buff. Introduced in: What the Firelight Casts
|
 MUS-Y
|
When the Musha Guard's HP is reduced to 0, they will survive with 30% HP. This effect can only be triggered once per deployment. Introduced in: [CN] Skógrinn Svartr Vill Einn Draumr
| |
|
 CEN-X
|
When the Centurion Guard attacks blocked enemies, their ATK increases to 110%. Introduced in: [CN] So Long, Adele
|
 CEN-Y
|
When the Centurion Guard's HP is above 50%, the Physical damage they take is reduced by 20%. Introduced in: [CN] So Long, Adele
| |
|
 REA-X
|
The HP restoration per hit in each attack is increased to 60. Introduced in: [CN] So Long, Adele
|
| Branch | Module | Description |
|---|---|---|
|
 RIN-X
|
The Multi-target Medic's range is extended to an adjusted 3×4 tiles with a 1-tile extension up front. Introduced in: Episode 9: Stormwatch
|
 RIN-Y
|
The Multi-target Medic can now heal up to four friendly units at once. Introduced in: Episode 9: Stormwatch
| |
|
 WAH-X
|
The Therapist Medic has Status Resistance and Negative Taunt. Introduced in: Stultifera Navis
|
 WAH-Y
|
Removes the healing penalty on further targets. Introduced in: Stultifera Navis
| |
|
 PHY-X
|
When the Medical Medic heals friendly units whose HP had fallen below 50%, the healing amount is increased by 15%. Introduced in: Il Siracusano
|
 PHY-Y
|
When the Medical Medic heals friendly units on melee tiles, the healing amount is increased by 15%. Introduced in: Il Siracusano
|
| Branch | Module | Description |
|---|---|---|
|
 DEA-X
|
The Deadeye Sniper's ATK is increased when attacking targets further away from their position, which caps at 15%. Introduced in: Episode 9: Stormwatch
|
 DEA-Y
|
The Deadeye Sniper generates 1 SP in each attack so long as the target is not defeated/destroyed (i.e. if the attack would defeat/destroy the target, no SP will be generated). Introduced in: Episode 9: Stormwatch
| |
|
 ART-X
|
When the Artilleryman Sniper attack blocked enemies, their ATK is increased to 110%. Introduced in: Guide Ahead
|
 ART-Y
|
The Artilleryman Sniper's attacks ignore 100 DEF. Introduced in: Guide Ahead
| |
|
 ARC-X
|
Reduces the Heavyshooter Sniper's redeployment time by 25 seconds. Introduced in: Episode 10: Shatterpoint
|
 ARC-Y
|
When the Heavyshooter Sniper attack enemies right in front of them, their ATK is increased to 105% and the attack will never proc the target's Physical Dodge. Introduced in: Ideal City
| |
|
 MAR-X
|
When the Marksman Sniper attack aerial enemies, their ATK is increased to 110%. Introduced in: Dorothy's Vision
|
 MAR-Y
|
If there are ground enemies within the Marksman Sniper's attack range, their ASPD is increased by 8. Introduced in: Dorothy's Vision
| |
|
 SIE-X
|
When the Besieger Sniper attack enemies with a weight of at least 3, their ATK is increased to 115%. Introduced in: What the Firelight Casts
|
|
 BOM-X
|
The Flinger Sniper's attacks now releases a second shockwave. Introduced in: [CN] Lone Trail
|
| Branch | Module | Description |
|---|---|---|
|
 EXE-X
|
When the Executor Specialist is retreated, 80% of their current DP cost is refunded. Introduced in: Near Light
|
 EXE-Y
|
If there are no friendly units in the adjacent tiles to the Executor Specialist, their ATK is increased by 10%. Introduced in: Near Light
| |
|
 MER-X
|
Reduces the DP drained by the Merchant Specialist when they are deployed to 2 DP every 3 seconds (also reduces the minimum DP threshold to automatically retreat the Merchant Specialist when there are insufficient DP to 1). Introduced in: Invitation to Wine
|
|
 PUM-X
|
The Substitute has +15% ATK. Introduced in: Stultifera Navis
|
 PUM-Y
|
The Substitute has +15% HP. Introduced in: Stultifera Navis
| |
|
 AMB-X
|
Reduces the speed of enemies within the Ambusher Specialist's range by 20%. Introduced in: Ideal City
|
 AMB-Y
|
Increases the Ambusher Specialist's innate Physical/Arts dodge rate to 65%. Introduced in: What the Firelight Casts
| |
|
 HOK-X
|
Enemies being dragged by the Hookmaster Specialist receive Arts damage based on how far they are dragged (see Debuff#Distance-based damage for more information). Introduced in: Ideal City
|
|
 PUS-X
|
When the Push Stroker Specialist is deployed on ranged tiles, half of their base DP cost are refunded. Introduced in: A Flurry to the Flame
|
 PUS-Y
|
When the Push Stroker Specialist is blocking at least two enemies, the shift force they deliver is increased by 1. Introduced in: A Flurry to the Flame
| |
|
 TRP-Y
|
There is a 20% chance that the trap deployed by the Trapmaster Specialist does double damage when triggered. Introduced in: [CN] Episode 12: All Quiet Under the Thunder
|
|
 GEE-X
|
When the Geek Specialist's HP is above 80%, their automatic SP generation rate is increased by 0.25/second. Introduced in: [CN] Hortus de Escapismo
|
| Branch | Module | Description |
|---|---|---|
|
 SUM-X
|
The first of the Summoner Supporter's summoned unit that are deployed will not be counted towards the Unit Limit, but the last will still be counted when they are destroyed or retreated. Introduced in: Dossoles Holiday
|
 SUM-Y
|
Increases the deployment count of the Summoner Supporter's summoned unit by 3 and reduces their DP cost (varies with the summon). Introduced in: Dossoles Holiday
| |
|
 DEC-X
|
If an enemy is inside the Decel Binder Supporter's range, their skill's SP generation rate is increased by 0.2/sec. (only if the Decel Binder's skill have automatic SP recovery). Introduced in: Episode 10: Shatterpoint
|
 DEC-Y
|
Extends the Slow duration of the Decel Binder Supporter's attacks to 1.2 seconds. Introduced in: Episode 10: Shatterpoint
| |
|
 UMD-X
|
The Hexer Supporter's attacks inflict 10% Weaken (reducing the target's ATK) for 2 seconds. Introduced in: [CN] Lone Trail
|
|
 CRA-X
|
Increases the deployment count of the Artificer Supporter's Support Devices by 1 and reduces their DP cost (varies with the Device) Introduced in: [CN] Hortus de Escapismo
|
|
 BLS-X
|
Increases the heal amount of the Abjurer Supporter to equal to 100% of their ATK. Introduced in: [CN] Come Catastrophes or Wakes of Vultures
|
| Branch | Module | Description |
|---|---|---|
|
 CHG-X
|
Increases the DP generated when the Charger Vanguard defeats an enemy to 2. Instead of the base DP cost, their current DP cost will be refunded when the Charger Vanguard is retreated. Introduced in: Break the Ice
|
 CHG-Y
|
When the Charger Vanguard attack enemies whose HP had fallen below 40%, their ATK is increased to 115%. Introduced in: Break the Ice
| |
|
 SOL-X
|
When the Pioneer Vanguard is blocking enemies, their ATK and DEF are increased by 8%. Introduced in: Il Siracusano
|
 SOL-Y
|
Reduces the Pioneer Vanguard's DP cost by 4 at their first deployment. Introduced in: Il Siracusano
| |
|
 BEA-X
|
The Operator in front of the Standard Bearer Vanguard has their block count increased by 1 when their skill is active. Introduced in: [CN] Skógrinn Svartr Vill Einn Draumr
|
