What Is an Opening Line?

An Othello opening (or "book line") is a sequence of early moves considered sound for both sides — paths that years of study have shown don't badly damage either player's position. You don't need to memorize them, but knowing the common shapes and the idea behind each one keeps you from collapsing in the opening.

The First Fork in the Road — Diagonal vs. Parallel

After Black's first move (in standard notation, f5), White's reply sets the character of the opening. Depending on the direction the discs are flipped, play divides into two broad families.

  • Diagonal openings: discs are flipped along a diagonal. These tend to be calmer and are friendlier to beginners.
  • Parallel (vertical) openings: discs are flipped in a vertical line. Contact is sharper from early on, and the variations get more cutting.

Start by getting comfortable with the diagonal openings first.

Named Openings

Othello openings have nicknames, often because the disc shape resembles an animal. You don't have to learn the names, but knowing that these shapes exist gives you a place to start.

  • Rabbit: a classic of the diagonal family. Well balanced — the natural first opening to learn.
  • Tiger: an aggressive line often chosen by Black, aiming to seize the initiative in the middlegame.
  • Cow: a slow, patient setup that builds calmly.

Play in Game Dojo and watch which shapes the engine's "Best" moves follow. The openings stick without much effort.

Three Principles to Keep in Mind Early

  1. Keep discs few and central. Don't spread early. Don't build walls.
  2. Don't play X- or C-squares early. Don't open a path to your own corner.
  3. Watch your opponent's moves. Increase your options and shrink theirs.
💡 Learn openings by meaning Understanding why a move is played (guarding a corner, preserving mobility) beats rote memorization — it transfers even when the game leaves the book.

When Your Opponent Leaves the Book — Your Chance

Opponents often won't follow the book. Usually, an off-book move is a loss for them. Don't panic — return to the basic principles (corners, mobility) and punish the slack.

Opening Entry Points (in coordinates)

Black's first move is almost always written as f5 (all four first moves are symmetric, so effectively one line). White's reply then splits the game into families:

  • Diagonal: White answers d6. Calmer, with beginner-friendly variations.
  • Parallel (vertical): White answers f6. Contact comes early and lines get sharp.
  • Rabbit: a diagonal-family staple — the natural first opening to learn.

No rote memorization needed. Get comfortable with a diagonal line first, and watch which shape the engine's "Best" moves follow — the openings sink in on their own.

An Order for Learning Openings

  1. Learn just the first 6–8 moves of one diagonal line.
  2. Then meet a parallel entry and feel the difference.
  3. When the opponent leaves the book, don't rely on memory — return to principles (corners, mobility).

Moves to Avoid Early

The opening "don'ts" are just the principles in reverse: X-squares (b2, g2, b7, g7), C-squares played while a corner is still empty, and moves that flip a big group and spread you across the board. Avoiding these three sharply lowers your odds of a bad opening.

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