Soy is a 2-player card game that uses a normal deck of playing cards (without the jokers). It takes under ten minutes.
Be the first to make your hand all one suit.
Play proceeds in a series of rounds. Both players play each round simultaneously. Ace is high, followed by King, Queen, etc. Two is low. All suits are the same value.
Start To begin, each player draws five cards (for a longer game, begin with six or seven cards).
Prize At the start of each round, two cards from the deck (the 'prize') are placed face up between the players.
Bid Each player chooses a card from their hand and places it face down in front of them. This is their bid for the face-up prize cards.
Reveal The face-down bid cards are revealed simultaneously. The player with the higher card wins both of the cards from the prize. The losing player picks up both bid cards.
Discard Each player then discards, face down, the surplus card from their hand.
Soy If either player has only one suit in their hand, they call "Soy" and win the game. It helps to say "Soy" repeatedly in a high, excitable voice, like Martin Prince on 'The Simpsons'.
New round If no-one calls Soy, a new prize of two cards is revealed from the deck and bidding begins again.
If both players bid a card of equal value, they must choose another card from their hand and bid that face-down as well. The winner of this second bid gets the prize. The losing player chooses three of the four face-up bid cards, and the winner gets the leftover bid card. If the second bid is also a tie, continue into a third bid, and so forth. If all bids are tied, the game ends on a tie (I've never seen this happen, but it's technically possible).
If both players call "Soy" at the end of the same round, the player with the lowest card wins. If both players have the same lowest card, use the second-lowest, and so forth. If all cards are of identical value, the game is a tie.
No more cards
If there are no more cards in the draw deck, both players reveal their hands, and the player with the lowest card wins. If both players have the same lowest card, use the second-lowest, and so forth. If all cards are of identical value, the game is a tie. Again, I've never seen this happen, but it could.
The game is a careful balance between winning the cards that you need and not giving your opponent cards that will help them win. Sometimes you will need to discard high-value cards because bidding with them will mean that your opponent can win.
Because you must discard a card each round, it's usually a good idea to pick your target suit early on, as it becomes harder to change further into the game. The most valuable cards are the low cards in the suit you're targeting, and the high cards in the suits you're not targeting (so you can bid with them).
It is valuable to know what suit your opponent is going for, because you can discard cards that they need. The only way to work out their target suit is through their behaviour, so pay close attention to the cards that they are bidding with. Sometimes you and your opponent will be going for the same suit - these games are particularly fun.