Star Cruiser is a guessing game played by two people, typically on a computer system.
The game is played on two square grids with three sectors each, one set of grids for each player. The grids are typically square, and the individual squares in the grid are identified by letter and number. On one grid the player arranges his own ships and records the shots by the opponent. On the other grid, the player records his own shots.
Before play begins, each player arranges a number of ships secretly on the grid for that player. Each ship occupies a number of contiguous squares on the grid, arranged either horizontally or vertically. The number of squares for each ship are determined by the type of the ship. The ships cannot overlap (i.e., at most one ship can occupy any given square in the grid). The types and numbers of ships allowed are the same for each player. These may vary depending on the rules.
After the ships have been positioned, the game proceeds in a series of rounds. In each round, each player has a turn. During a turn, the player announces a list of target squares in the opponents' grid which are to be shot at, or he may launch a probe. If a ship occupies one of the squares, then it takes a hit. When all of the squares of a ship have been hit, the ship is destroyed. If at the end of a round all of one player's ships have been destroyed, the game ends and the other player wins.