Swap is played with four standard dice and 12 chips in each of four colors. Players start with one chip of each color and the rest are placed in a row of supplies.
At the start of each round the dice are rolled and assigned to the chip supplies - the color on the left gets the highest die, the next color gets the second-highest, etc. Then each player in turn may trade; they can turn in chips to the supplies and take chips, but they must obey two rules: the total value of the chips taken cannot exceed that of those turned in, and at most one chip of each color can be traded.
After each round the start player moves. The winner is the first player to have two chips of each color. If playing solo the object is to reach this goal in as few turns as possible.
The book versions of the game include variants:
- In Sway Swap the dice are not rolled each round; instead they are rolled all together only at the start of the game. On a player's turn they choose a die to roll, after which they re-order the dice and then may trade.
- In Sellout the die rolling is handled as in Sway Swap, but it uses dice in colors matching the chips instead of ordering the dice. In this version the game continues until there is only one chip left in the market, at which point the player with the most chips wins.