Reversi
The flip side of strategy
Victorian board game Reversi—later trademarked as Othello—became a computer gaming staple, teaching territory control and forward thinking.
Reversi originated in Victorian England, with two inventors claiming credit in the 1880s. A century later, it found new life on home computers—simple enough to implement in a few kilobytes, deep enough to challenge players and programmers alike. The trademark “Othello” made it famous in Japan and worldwide.
Fast facts
- Invented: 1883 (disputed between Lewis Waterman and John Mollett).
- Othello trademark: Japanese businessman Goro Hasegawa trademarked a streamlined version in 1971.
- Board: 8×8 grid. Players take turns placing discs that are light on one side, dark on the other.
- Core mechanic: place a disc to outflank opponent pieces in a line—those pieces flip to your colour.
- Victory: when the board is full, whoever has more discs wins.
The rules
- Outflanking: your disc must trap opponent discs between itself and another of your discs (horizontally, vertically, or diagonally).
- Flipping: trapped discs flip to your colour immediately.
- Forced moves: if you can’t make a legal move, you pass.
- Endgame: the game ends when neither player can move. Count the discs.
Strategy depth
Reversi’s simple rules hide substantial depth:
- Corners are king: corner squares can never be flipped—controlling them dominates late game.
- Edge play: edges are stable but corners matter more.
- Mobility: having more move options often beats having more discs mid-game.
- Sacrifice: sometimes giving up pieces now secures better positions later.
Computer implementations
Reversi appeared on nearly every 8-bit platform:
- Type-in listings: magazines frequently published Reversi as a programming exercise.
- Commercial versions: dedicated Othello games from various publishers.
- Built-in: some platforms included Reversi in ROM or bundled software.
The game’s appeal for early home computers was practical:
- Simple graphics: an 8×8 board with two piece colours required minimal resources.
- Clear rules: easy to implement, easy to debug.
- AI challenge: writing a competent opponent taught tree search and evaluation functions.
Why it matters for learning
Reversi teaches fundamental game programming concepts:
- Board representation: 2D arrays, state management.
- Move validation: checking lines in eight directions.
- Flipping logic: updating multiple cells from a single move.
- AI fundamentals: minimax, evaluation functions, difficulty scaling.
Our Ink War game uses Reversi-style territory mechanics on the ZX Spectrum, teaching these concepts through assembly language.