The complete rules of Othello on one page — opening setup, what makes a move legal, flipping, passing and scoring — plus the corner strategy that decides nearly every game.
| Opening | Four discs in the centre, two of each colour, placed diagonally. Black moves first. |
| Legal move | Place a disc only where it outflanks at least one straight line of opponent discs — bracketing them between your new disc and another of yours. |
| Flipping | Every opponent disc you outflank flips to your colour — horizontally, vertically and diagonally, all directions at once. |
| Passing | No legal move? You pass and your opponent goes again. If neither side can move, the game ends. |
| Winning | When the board is full or no moves remain, the player with more discs wins. |
Othello takes a minute to learn and considerably longer to play well. The board starts with four discs in the centre — two black, two white, placed diagonally — and black moves first.
You may only place a disc where it outflanks at least one unbroken line of your opponent's discs, bracketing them between the disc you just played and another of your own. If a square does not outflank anything, you cannot play there — even if it is empty.
Every opponent disc you outflank flips to your colour, in all directions at once: horizontal, vertical and diagonal. A single well-placed disc can flip lines in three directions simultaneously.
If you have no legal move, you pass and your opponent moves again. This is not optional — you may not decline a legal move to pass. When neither player can move, the game ends, which sometimes happens before the board fills.
Count the discs. Most of your colour wins. A game ending 32–32 is a draw.
Corners are permanent. A disc in a corner can never be outflanked, because there is no square beyond it to bracket from. Corners anchor whole regions of the board, and games are usually decided by who takes them.
Avoid the X-squares. The diagonal square adjacent to a corner is the most dangerous on the board — playing one typically hands your opponent the corner next to it.
Mobility beats majority. This is the idea that separates beginners from decent players. Holding the most discs in the midgame is usually a disadvantage: every disc you own is a square your opponent might flip, and a large mass restricts your own options. Aim to have few discs and many legal moves around move 40, while your opponent runs short of playable squares.
Quiet moves beat greedy ones. Flipping the maximum number of discs each turn is a reliable way to lose. Play for structure instead.
They describe nearly the same game. Reversi is the 19th-century original, in which players placed the first four discs wherever they liked. Othello is the 1970s standardisation: fixed diagonal opening, fixed 8×8 board. The rules above are the modern Othello rules everyone now uses.