French deck! Basically, everyone gets a hand of cards and works together to solve problems by playing cards with a total that's (hopefully) below a target number. Cards are played face-down and you can't say what you're playing, so it's possible to go over by accident. Playing a card by yourself is easier but never as good, and you can get more cards by roleplaying (including screwing yourself/other people over). The aim is to make it to the final challenge with a good enough hand to overcome it.