Reversi is played with 64 stones that have a white and a black side, on a board consisting of 8x8 squares. The game starts with 2 stones for each player, crossed and in the center of the board. The goal of Reversi is to get more stones than the opponent on the board.
Taking turns, the players place a stone in their own color on the board, so that at least 1 opponent's stone is between the placed stone and one of the other own stones (horizontal, vertical and/or diagonal). The intermediate stones are turned over to the color of the current player. A move is not valid if no stones are turned over.
The game ends when one of the players is unable to make a move or when all squares on the board are occupied. The player with the most stones on the board wins the game.