Fluxx is a card game in which the cards themselves determine the rules! Each player starts the game with three cards in their hand. On their turn, player draws one card, then play one card. By playing cards, you can put new rules into play that change numerous aspects of the game: how many cards to draw or play, how many cards you can hold in hand or keep on the table in front of you, and even (most importantly) how to win the game!

Cat Fluxx features felines and familiar Fluxx gameplay, with the game featuring nine Cat breeds, The Human, a laser pointer, new actions such as "The Zoomies" and "Objects on Shelves Must Be Pushed Off", and new rules such as "Live Cat Bonus" (which has you draw an extra card each turn while a cat is in the room).