Reversi openings

The first move

Black has 4 possible first moves: d3, c4, f5 and e6. The starting position is symmetric, so all 4 lead to the same position, only rotated or mirrored. By convention, games and opening lines are written as if Black started with f5.

White's 3 replies

After f5, White can answer in 3 ways, and each one has a name:

• Perpendicular opening: d6
• Diagonal opening: f6
• Parallel opening: f4

The perpendicular and diagonal openings are the main lines. The parallel opening is considered weaker for White, and strong players rarely choose it.

Opening principles

• Flip few discs. Quiet moves that flip 1 or 2 inner discs keep your options open. See mobility.
• Stay in the middle. Avoid edges early, and above all the X-squares and C-squares next to empty corners. See corners.
• Don't build walls. A long row of your discs facing empty squares gives your opponent many moves.
• Count your opponent's replies. Before each move, check how many moves it leaves your opponent.

Named openings

Tournament players have named many opening lines. The early names describe the shape the discs make on the board, and later ones are named after players who made them popular. Some well-known lines:

Knowing a few lines helps you reach a playable middle game, but understanding why the moves are good matters more than the names. Open the Tiger on the game board and continue from there against the computer.

After the opening

Once the opening is over, the ideas from the other guides take over: mobility in the middle game, corners and stable discs, and parity at the end.

• Previous guide: Parity
• All strategy guides
• The rules and notation