Fire mode is a non-complex method of representing variance in Equipment output.

All weapons and some support items have fire modes, though most only have one. The number of fire modes is visually indicated by the bubbles next to the icon of the Equipment in a holster slot. The specifics of how a fire mode affects the output is left to implementation and execution. Contrast how Tools deal with multiple types of ammunition.

While most Tools - weapons and such - are known to have fire modes, ConstructionItem equipment that produce deployable entities in the game world also support fire modes. The mechanism is different, however, even while the user interactions work in a similar way. For most weapons, the fire mode is just a modification of how the projectiles behave or the weapon behaves. For example, the bounciness of the grenades or the number of shots fired by the Jackhammer. One has to change tool ammo types to actual swap out different ammunitions such as, most commonly, grey normal ammo for gold armor-piercing ammo. For deployable-constructing entities, fire mode switches between the categories of deployables that can be built and "changing ammunition" actually changes the subtype of deployable within that deployable category. For example, fire modes go from "Boomers" to "Mines" while ammo types for "Mines" goes from "HE mines" to "Disruptor Mines".