The general idea behind a sanity system would be more about... making it more challenging the more you survive, it's NOT designed to combat the 'bandit problem'. The reasoning is simple - when put into a situation like this (a zombie apocalypse) it's quite possible for people to go completely bonkers, especially considering they might be already infected. This could be used to make the game more challenging the more you survive and underline the idea, that you will die eventually. Or that generally the more survive, the more sh*t you are in. ;) How it'd work? Let's say that every day there's a slight chance that our "bonkers rating" might go up. This indicates what symptoms we might have. The implementation is not really relevant, it might be roll to check, it might be some kind of points system that is tracked and influenced by events. Doesn't matter, although generally I'd be interesting if some events (long time with no food or water, trauma) could speed up the process. Once the symptoms escalate you might hear some zombie growls every now and then, see one running at you, hear gunfire etc.. The idea is to throw you off-guard, possibly making you alert some zombies, or just generally make a bit of noise (as well as spooking out teammates :P). This can add some potential tension, especially in groups, and every day you survive means the next one is gonna be tougher... and you should realise, that in the end you will either die or go mad, possibly killing other people. This could actually be interpreted as the infection slowly taking over, blurring the player's understanding of the world, turning them into the monsters they are hunting. Would give people a bit of a sense that all hope is truly lost, and your fight is futile. Possible effects: - Hearing growls of zombies/gunfire - Seeing zombies that are not there - The possibility to seeing survivors at long distances - Illusionary loot, clips that you never had, foot that had already been eaten - Mistaking survivors for zombies and vice versa - And so on and so on This combined can actually make the experience quite unique, actually give you increasing challenge as you progress and generally provide fun and amusement to groups, as well as lone players. Who doesn't love getting shot because a friend wanted to get rid of an imaginary zombie? :)