Four Dimensions is a tricky set-taking game. From your hand, play a set of cards that share at least one trait. Each trait your set has in common allows you to score off of other player's cards. Your cards remain in front of you for others to score from until it is your turn again. There's an ebb and flow of scorable cards as players want to follow with similar traits, but also go in a slightly different direction. As you play, traits get progressively closed off. Play continues until someone can't play a set of available traits.