Spades

Spades is the partnership game built around a promise. Four players in two partnerships each bid the number of tricks they expect to take; a side that lands its combined contract scores ten points a trick bid, one for each trick over, and a side that falls short loses the lot. Spades are always trump, the suit that gives the game its name, and they may not be led until one has been played on another suit's trick.

Zero is a bid of its own. Nil is a promise to take no tricks at all, worth a hundred points made and minus a hundred failed, and covering a partner's nil is half the art of the game. You play with a computer partner against two computer opponents at three strengths, or open a table and send the room code to three friends.

You bid from a row of buttons rather than typing a number. Nil sits at the front of the row in its own colour, with a note of what it pays and what it costs if you fail. The bids already made appear above the row as they arrive, so you are never promising tricks blind. Only the strongest computer will bid nil, and only on a hand that warrants one. Your difficulty and your record stay in this browser.