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.