Minor modules are the player's main offensive and defensive tools along with Heroes. Unlike Major Modules, minor modules only affect the room that they are built in, but they directly affect enemies instead of indirectly. Building minor modules requires Industry and a minor slot in the current room, along with power. Massing minor modules of varying types can create a very powerful room to fall back on, capable of saving heroes or weakening an onslaught of enemies. Earning new minor modules requires researching or upgrading them through Artifacts. The effects of multiple minor modules of the same type stack.

All minor modules have 15 defense regardless of level. This means a level 1 LAN Module will make all minor modules have 30 defense total, effectively 30% extra HP (15% from the LAN).

These modules are designed to aid heroes by directly affecting them. They act as buffs for heroes or produce resources.

These modules have one purpose: deal damage to any and all enemies foolish enough to enter the room.

These modules work to debuff or distract enemies, decreasing their overall performance.