Card Color Theory – have a deck of rainbow cards. Each color is assigned a value based on color theory. You have to get to a certain color value by mixing colors without making a muddled brown color. Like blackjack, but with colored cards instead of numbered cards.
Jimmy Sprinkles – there are six piles of four cards face down in front of each person (2 players) and four face up cards between them. Looking at one group of four at a time, you can swap out cards from that group with the face up cards in the middle. You must have four cards in each ‘hand’ at a time. The goal is to have four matching cards. Once you have a matching four card set, that ‘hand’ is laid down face up. Cards can no longer be traded in or out of that group. The goal is to be the first person to get all six of their ‘hands’ face up AND shout Jimmy Sprinkles. Why Jimmy Sprinkles? I don’t know, it sounds funny.
Four Kingdoms – each suite is a kingdom (13 cards). Players take turns playing war, capturing the fallen card and setting them aside. Once the player is out of their original 13 cards from their own suite, they must use their captured cards to keep playing. However, if they play a hand of war with a captured suite against that suite’s original kingdom, the original kingdom automatically wins and discards the challenger from play (no matter the card point total). The last man standing wins.
Mismatch – several mismatched decks of cards are mixed together and divided evenly among the players. Players take turns playing war. Card numbers are important, but so are the decks the cards came from. For example, red themed cards have a plus one against blue themed cards, blue themed cards have a plus one against Tennessee tchotchke novelty themed cards, and Tennessee themed cards have a plus one against red themed cards. The card number + the color/theme bonus = total card value. If your total card value is higher than your opponent’s, you win that round and the challenger is eliminated from play. Last person with cards wins.
Fridge Magnets – the deck has many different words, each printed on its own card. Players must make a poem/sentence/joke out of the cards from their hands. Only play one word at a time, draw a new word at the end of the hand. First person to make a coherent phrase wins.
Mismatch is a great revision of War and worth a test. Would players have 4 total decks to play with or would they only get 52 mismatched cards?
I can see two possible ways for this game to play out. There could be 4 decks total mixed together for a full game or there could be 13 (one full suit) of each type mixed together for a much shorter game. I might consider having both options (with the same mechanics) to alter the length and complexity of the game.