On each turn each player gets five rolls and tries to gather "crab points." You must roll, in this order, 3, 4, crab (1), 2 and 5 (6's aren't counted). You can't set aside a 4 or crab until you've rolled the 3. Each time you roll those numbers in that order, you get two crab points. You have five rolls to get as many of those crab points as possible. High score wins! The game comes with 5 Crab dice. These have orange pips 2 thru 6 and an orange crab ace. These are 16mm (about 5/8") and are the size most often used in board games. A bonus: On the back of the instructions are some interesting facts about crabs. A nature lesson too! Quick, easy & fun. A great way to help children with math skills - adding and subtracting. Let them keep score. A fun family game!