Chatsys is a very simple ad-hoc system used most often in CIRPs. For each action to be taken, a d6 is rolled. A 1 is typically a failure and any higher number is a success, but for harder actions, a higher number might be required. For opposed actions (such as attacks), each person rolls a d6 and the one who has the higher number is the winner. In combat, each combatant has a specified number of hit points (typically 6), the combatants take turns, and for each attack not successfully defended against, the defender loses one hit point. In this variation, rolling a 6 may deal two hit points of damage.