How to Play Reversi

Reversi (also marketed as Othello) is a two-player strategy board game played on an 8×8 uncheckered board with 64 identical discs that are black on one side and white on the other. The objective is simple: when the last playable square is filled, the player with the most discs showing their color wins. Though the rules take only a minute to learn, the shifting alliances of the board create deep, dynamic gameplay that rewards planning, patience, and positional awareness.

Board and Equipment

Reversi uses an 8×8 square board with no coloring distinction between squares. There are 64 discs in total, each with a dark (black) side and a light (white) side. In physical sets, the discs are flipped to change color; in digital versions, the color change is animated automatically.

• The board is labeled with columns a–h and rows 1–8 for notation purposes.
• All 64 squares are used during play — there are no restricted or off-limits areas.
• The supply of 64 discs is more than enough: at the start only 4 are placed, and no discs are ever removed from the board once played.

Starting Position

Before the first move, four discs are placed in the center of the board in a specific diagonal pattern:

1. Place a white disc on d4 and a white disc on e5.
2. Place a black disc on d5 and a black disc on e4.
3. The four center discs form an alternating diagonal pattern — each color sits diagonally opposite itself.
4. Black always moves first in standard Othello rules.

Placing a Disc (Outflanking)

On your turn you must place one disc of your color on an empty square that outflanks at least one of your opponent's discs. A disc outflanks when it creates a straight, unbroken line — horizontally, vertically, or diagonally — between the newly placed disc and another disc of your color, with one or more opponent discs in between.

• You may outflank in up to eight directions from a single placement — left, right, up, down, and all four diagonals.
• The line must contain no empty squares between the two friendly discs; every square in the line must be occupied by an opponent disc.
• A single move can outflank discs in multiple directions simultaneously. All outflanked discs from every direction are flipped as part of one turn.
• If you cannot outflank any opponent disc, you have no legal move on that turn.

Flipping Discs

After you place your disc, every opponent disc that is outflanked is flipped to your color. This is the heart of Reversi — the board can change dramatically with a single well-placed disc.

• Flipping happens in all directions where outflanking occurs. If your placement outflanks discs horizontally and diagonally, both sets are flipped.
• Only the discs directly outflanked by the placed disc are flipped. Discs flipped on this turn do not create chain reactions or trigger further flips.
• You must flip all outflanked discs. You cannot choose to flip only some of them.
• Once a disc is flipped, it stays in its new color until it is outflanked again in a later turn. Discs are never removed from the board.

Passing

If you have no legal move — that is, there is no empty square where placing a disc would outflank at least one opponent disc — you must pass your turn. Your opponent then plays again.

• Passing is never voluntary. If you can make a legal move, you must do so.
• Your opponent may also have to pass on their next turn if they have no legal move, at which point the game ends.
• It is possible for the same player to move several times in a row if the other player keeps having no legal move.

End of the Game

The game ends when one of two conditions is met:

• The board is completely full: all 64 squares are occupied by discs.
• Neither player can move: both players must pass in succession, meaning no legal outflanking move exists for either side, even though empty squares may remain.

Once the game ends, count the discs. The player with more discs of their color on the board wins. If both players have exactly 32 discs, the game is a draw. In tournament play, the margin of victory (difference in disc count) is often recorded.

Strategy Tips

While the rules of Reversi are straightforward, strategic play separates beginners from experienced players. Here are the core principles to keep in mind:

• Corners are king: Corner squares (a1, a8, h1, h8) can never be flipped once captured. They anchor your position permanently and allow you to build stable edges.
• Edges are valuable: Discs along the edges of the board are harder for your opponent to outflank because they can only be approached from fewer directions.
• Mobility matters: Try to keep many legal moves available. A player with few moves may be forced into poor positions, while a player with many options can control the pace of the game.
• Avoid the X-squares: The squares diagonally adjacent to corners (such as b2, b7, g2, g7) are dangerous early in the game because they can give your opponent access to the corner.
• Fewer discs early, more later: Counter-intuitively, having fewer discs in the early and middle game can be advantageous. It gives your opponent fewer targets to outflank and limits their options.

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