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Players alternate placing discs on an 8x8 grid. A disc may only be placed in a position that sandwiches at least one opponent disc between the new disc and another disc of your color, in any of the eight directions. All sandwiched opponent discs are immediately flipped to your color. The game ends when neither player can make a valid move. Count discs: the player with more discs of their color wins.
Corners are permanent; once captured, they cannot be flipped regardless of subsequent play. Control even one corner early and you gain a stable region from which to build. Edges are similarly stable once anchored to a corner. Avoid playing into cells diagonally adjacent to any empty corner, since this frequently allows your opponent to capture that corner on their next move. Counterintuitively, sacrificing disc count early in the midgame to deny your opponent mobility often produces superior endgame positions.
The game was derived from an 1880s English game called Reversi and was relaunched under the name Othello in Japan in 1971. Mattel acquired the rights and marketed it widely in the United States and Europe from 1975 onward. The World Othello Championship has been held annually since 1977 in various countries, with strong competitive scenes in Japan, the United States, and several European nations. Its simple rules combined with deep strategic requirements have made it a long-running subject of computer science research into game-playing algorithms.
The classic beginner error is greedily flipping the most discs on every turn. Reversi rewards the player who controls the board at the very end, not the one ahead midway, and a fat lead in the midgame frequently collapses as the opponent flips long lines back. The single most costly mistake is playing into an X-square or C-square, the cells diagonally and orthogonally adjacent to an empty corner, because doing so hands your opponent the corner on their next move. Corners can never be flipped, so giving one away is often irreversible. Another trap is filling your own region until you have no safe moves left and are forced to play a damaging square; this is a mobility failure. Strong play keeps your disc count low and your options open in the early game, treating each move as a question of which squares it forces your opponent to use, not how many discs it earns right now.
Two ideas separate intermediate play from strong play in Reversi: mobility and parity. Mobility is the number of legal moves you have; the more your opponent's choices shrink while yours stay open, the more you can steer them into the X-squares and C-squares that surrender corners. This is why deliberately holding a small disc count early, counterintuitive as it feels, is a winning idea: fewer of your discs on the board usually means more flipping options later. Parity concerns who is forced to move last in each empty region of the board. Because the player who places the final disc in a sequence often flips the most, controlling parity, arranging for your opponent to run out of safe moves first, can swing close endgames. Count the empty squares in each enclosed region and aim to be the one who fills the last square there.
Reversi is decided only when the board is full or no moves remain, so a midgame lead means little. Long lines flip in a single move, and a player who held back early often controls the corners and edges that lock discs in place during the decisive endgame.
X-squares are the cells diagonally adjacent to a corner. Playing one usually lets your opponent capture that corner next turn, and corners can never be flipped. Avoid X-squares and the adjacent C-squares while the corner beside them is still empty, or you may hand over a permanent stronghold.
Usually not. Holding a low disc count early tends to give you more legal moves later, letting you pressure your opponent into bad squares. Many strong players deliberately stay behind in count through the midgame and surge ahead only as the board fills.
They are nearly the same game. Reversi is the older 1880s English version with looser setup rules. Othello, trademarked and relaunched in Japan in 1971 and marketed by Mattel from 1975, standardizes the fixed four-disc starting position and the 8x8 board used here.
If you cannot place a disc that sandwiches at least one opponent disc, your turn is skipped and play passes back to your opponent. The game ends only when neither player can move, which is not always when the board is completely full.