Fighting Sail is a fairly simple naval wargame. It is played on a triangular grid, with the ships moving from intersection to intersection. The ships are represented by pieces of wood with holes drilled to hold small flags; the position of the flag in a ship represents its speed. The color of a flag represents how many operational guns the ship has.
Movement is performed by spending one knot (movement point) for each intersection moved and/or each 60 degrees turned. Ships may not sail directly into the wind, which may shift at the start of each round (based on a die roll).
When a ship fires at a target it declares whether it is aiming at the decks or the rigging and rolls on the appropriate table. The die roll needed to hit further depends on the number of guns the attacker has, the class of the target (1st, 2nd, or 3rd rate), the range, and whether the target is beam on or end on to the attacker.
There are a few additional rules for heaving to and boarding.
The rules were published in Games & Puzzles #1 (May 1972).