- Four players each receive 13 cards dealt one at a time from a 52-card pack ranking AKQJ1098765432 in each suit.
- To win exactly the same number of tricks as one other player (but not two others, for reasons that will become apparent).
- The player at dealer's left leads to the first trick and the winner of each trick leads to the next. You must follow suit if you can, but may play any card if you can't. A trick is taken by the highest card of the suit led. There are no trumps.
- During the course of play any two players may at any time collude by agreeing to try to both finish up with a specific number of tricks. For example, you might say "I'm going for four", or "I probably won't take any more", or "Does anyone think they're aiming for three?", or "Are you likely to win another trick?". You may ask another player to lead or avoid leading a particular suit, or a high or a low card, or what suit they want you yourself to lead or to avoid leading. What you may not do is reveal your cards or state anything about what you are actually holding. No penalty need be specified: breaking this rule merely spoils the game. All such agreements are informal and non-binding: you can make or break alliances as you see how things develop. (Not for nothing do we tend to refer to Collusion as "the Talking Game".)
You score 1 point for each trick you took, and possibly one of the following bonuses:
If exactly two players win the same number of tricks, they each add a bonus of 10.
If no two players win the same number of tricks, then whoever won fewest adds a bonus of 20.
If three players win the same number of tricks, the fourth player adds a bonus of 30.
- Game is 100 up. You may only reach the target with the aid of a bonus, not on tricks alone. If you win a number of tricks that would take your score into the hundreds, but fail to get a bonus, you must deduct that number from your current total instead of adding it.
- A good thing to aim for at start of play is to lose every trick if you can (since you will win if no two others take the same number), or to go for four, seven or ten tricks, as these targets favour your chances of getting the 30-point bonus. Failing that, and unless and until you come to an understanding with someone in particular, the next best target is a number most likely to be matched by another player. For this purpose you may wish to know that although the average number of tricks taken per person per deal is 3.25, the commonest number actually won is two, so this is a good target to aim for when you are in the 90s and are looking for that winning 10-point bonus. It often helps to lead and play cards of middling rank, and to avoid deciding on a specific quota of tricks until you have seen how many of them are winners and losers. It is vital to keep track of what other players discard, even when they follow suit to a winning lead.