Setup
Start with four discs in the four center squares: place two of each color on the two diagonals, so each color sits on opposite corners of the center 2×2. One player is "light", the other "dark". Dark moves first.
The goal
Have more discs of your color on the board than your opponent when no more moves are possible. The board flips back and forth all game, so a big lead can vanish — it’s anyone’s game until the end.
Making a move
On your turn, place one disc of your color on an empty square so that it "outflanks" a straight line of one or more of your opponent’s discs — meaning your new disc and another of your discs bracket them, with no gaps.
- Outflanking works in any straight line: horizontal, vertical, or diagonal.
- Every opponent disc you bracket flips to your color — and a single move can flip discs in several directions at once.
- You must flip at least one disc on every move. If you can’t, you forfeit your turn.
Passing and ending
If you have no legal move that flips at least one disc, you pass and your opponent plays again. When neither player can move — usually when the board is full — the game ends.
Winning
Count the discs. Whoever has more of their color on the board wins; equal counts are a draw. Corners are powerful because a disc in a corner can never be outflanked — grabbing them is the heart of Reversi strategy.
