# OthelloGame.app

> Free browser game for playing Othello (Reversi) online against a computer opponent (5 levels) or a second player on the same device. No sign-up or download; the AI runs locally in the browser.

Canonical: https://othellogame.app/

## What the site offers
- Play Othello vs computer: Novice, Casual, Club, Strong, Master. Strong solves the last 14 empty squares perfectly; Master thinks up to 2.5 s per move and is perfect from 16 empty squares.
- Two-player pass-and-play mode.
- Legal-move indicators, hover preview of flips, hints, unlimited undo.
- Post-game review: every move compared with the best move (6-ply search, exact from 14 empties), advantage graph, mistakes ranked in discs lost.
- Shareable replay links (?g=<moves>, e.g. https://othellogame.app/?g=f5d6c3d3c4).
- Games, settings and win/loss record saved in the browser's localStorage; no accounts. Optional Google Analytics loads only after visitor consent.

## Rules summary (standard Othello rules)
- 8x8 board; start: white d4 & e5, black d5 & e4; Black moves first.
- A move must outflank (bracket) at least one straight line of opponent discs; all bracketed lines flip at once; no chain reactions.
- No legal move: pass (mandatory, and only then). Neither side can move: game over.
- Most discs wins; under World Othello Federation scoring, empty squares go to the winner.
- Shortest possible game: 9 moves (e6 f4 e3 f6 g5 d6 e7 f5 c5), Black wins 13-0.

## Key pages
- Play Othello online: https://othellogame.app/
- How to play Othello (rules with diagrams): https://othellogame.app/how-to-play/
- Othello strategy (corners, X/C-squares, mobility, parity, openings): https://othellogame.app/strategy/
- Othello vs Reversi (differences and history): https://othellogame.app/othello-vs-reversi/
- About, editorial policy, AI design: https://othellogame.app/about/
- Contact: https://othellogame.app/contact/ (contact@othellogame.app)
- Privacy policy: https://othellogame.app/privacy/
- Terms of use: https://othellogame.app/terms/

## Sources used
- Official rules: https://www.worldothello.org/about/about-othello/othello-rules/official-rules/english
- History: https://en.wikipedia.org/wiki/Reversi

## Notice
OTHELLO is a registered trademark of MegaHouse Corporation. OthelloGame.app is an independent site that teaches and hosts the public-domain game Reversi under the standard Othello rules; it is not affiliated with, sponsored or endorsed by MegaHouse or the World Othello Federation.