Weapon mods are a big part of how weapons come together in Marathon. Mods help shape how a gun handles, how it reloads, how steady it feels, and how it fits into your whole build. Marathon also treats mods as part of its larger buildcrafting system alongside weapons, implants, and cores.
This page is here to make that system easier to understand. If you are trying to figure out what a Chip mod does, which attachment types exist, or how modded weapons are different from their base versions, we have all the information here. Marathon launched with 29 weapons plus mods, and future seasonal updates can keep expanding that pool.
The easiest way to think about Marathon weapon mods is this: chip mods are the most universal part of the system, meaning all weapons can use all chip mods. That said, other mod slots depend on the weapon itself. There are five types of weapon mods available in Marathon right now: Magazines, Barrels, Grips, Optics, Shield, and Generator.
Weapon mods are managed outside of runs. Marathon lets you freely swap weapon mods out of run, and inspecting a weapon opens its mod workbench, which is where you handle changes before heading back in.
