Mayhem is an ability of the Heavy Class in XCOM: Enemy Unknown.

Confers additional damage based on weapon tech level to Suppression and all area-effect abilities.

– In-Game Description, XCOM: Enemy Unknown


The additional damage is one point per weapon tech level; this goes from 1 damage with the LMG, to 2 damage with the Heavy Laser and deals its maximum of 3 damage when equipped with the Heavy Plasma. The damage is unavoidable, unaffected by either the soldier's Aim or the enemy's Defense and Cover. If the soldier also has Danger Zone, this essentially turns the Suppression ability into something like a grenade with less damage, albeit with unlimited uses per mission.

Mayhem also increases the damage output of the Rocket Launcher and the Blaster Launcher by +2 and +3 respectively; it does not increase the damage output of grenades.