Reversi rules
Standard opening four discs
Overview
Reversi (Othello) on 8×8. Place discs to bracket and flip opponent pieces. White moves first.
Objective
Have more discs of your colour when the game ends. Equal counts are a draw.
Game setup
Centre squares: d4/e5 White, d5/e4 Black. All other squares empty.
Placing at f4 flips bracketed discs
How to make moves
Play on an empty square that flips at least one opponent disc. A line of enemy discs must lie between your new disc and another of your colour, in any of eight directions.
Passing
If you have no legal move, pass. If both players pass consecutively, the game ends and discs are counted.
Edge cases
Cannot pass with moves available
Pass is illegal while a legal placement exists.
Full board
Game ends when all squares are filled — no double pass required.