Oz Fluxx

From BoardGameGeek:

Does life seem drab and humdrum? Let the cyclone of Oz Fluxx, the ever-changing card game, whisk you away to a magical world of fun and wonder! Mingle with Munchkins, make new friends, help them with their quests, and follow the Yellow Brick Road to seek the Wizard's help for your own heart's desire – but beware the flying monkeys, fighting trees, and fields of poppies! Don your green spectacles to enter the Emerald City, and keep a bucket of water handy: You never know when you'll run into a Wicked Witch that needs melting. Next stop...the land of Oz! Game description above from the publisher. Fluxx is a card game where the cards themselves determine the current rules of the game. By playing cards, you change numerous aspects of the game: how to draw cards, how to play cards, and even how to win. At the start of the game, each player holds three cards and on a turn a player draws one card, then plays 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 (most importantly) how to win the game. There are many editions, themed siblings, and promo cards available.