Systems are a way of getting players to play as a group. Systems start at 100% and gradually decrease to 0%. Once they reach 0%, all players lose the game. To repair them, two players must interact with a lever at the same time, which gradually increases the percentage back up to 100%.

Additional ideas: It takes two systems at 0% to lose the game. When a system drops to 0%, it is more repairable and, depending on the system, can also influence the game (e.g., lights going out).