Inspired by Sid Sackson's classic abstract Focus, Crossfire is a stacking game played on a hexagonal grid.
Piece stacks have a maximum size dependent on how many neighboring hexes it has. Excess pieces in a stack are removed from the bottom by the stack's controller and either returned to the stack controller's reserve to return to the board later, or else are captured and removed from the game.
A move consists of a player moving either a stack he controls, or pieces from the top of a stack he controls, and then moves those pieces in a straight line a number of spaces up to the number of pieces being moved. Alternatively, a player may introduce a piece from his reserve onto any space on the board.
The game is won when he forces his opponent into a position where his opponent cannot make a move.