Proc

In the Stash RPG, proc enchantments aka pre-prefix enchantments can be put on a weapon to give it elemental proc and on armor to give it elemental resistances.

Basic Information
A proc on a weapon can attack for 75% to 100% of the TWD. The proc only triggers when you use an ability of the same element as the proc enchantment on first matching ability hitting a mob (fire element ability to proc fire proc enchantment). You are to hit 2 mobs with any type of attack (Or in the same attack with AoE) to recharge the proc before triggering it again.

Etymology
is abbreviated of  P ogrammed R andom OC curance. Short for spec_proc (special procedure), which is a bit of code triggered to cover a special case that the default code doesn't handle.

The term is mainly used in RPG's to describe a special ability that an item/weapon/armor has, something which is bound to occur if the proper conditions are met enough times.

In short, is a term describing the act of triggering a tactical ability in order to gain advantage in combat.