Players in Crab Stack represent a family of crabs who don t start out stacked, but who will become stacked over the course of the game, preferably being top crab in the end.
Each player has nine crabs — three large, three medium and three small — and they start in random locations on the game board at the start of play. On a turn, you move exactly one of your crabs — with a large crab moving exactly one space, a medium crab exactly two, and a small crab exactly three — so that you land on top of another crab of the same size or smaller, pinning it and preventing it from moving as long as you sit there.
You can t move over open water, and if your move splits the cast of crabs, then the smaller group is washed away by the waves.
If you can t move on your turn, then you re out of the game — even if one of your crabs is left uncovered later. The last player who makes a move wins!