An opponent that explains itself
Most engines hand you a move and leave you to guess why. GomokuZero plays, then tells you what it was thinking: what shape your last move built, what its reply took away from you, which alternatives it weighed and why it passed on them — and it defines the vocabulary as it uses it, so "open three" and "four" stop being jargon the first time you meet them.
Ask it anything at any point: suggest a move for me, why not here?, or what decided this.
Play
Against the engine — a neural network trained by self-play, at four strengths from a gentle introduction to a level that will not be flattering you.
Three rule sets — freestyle, standard, and renju with its forbidden moves for black.
Two players, one screen — with a clock if you want one.
Online — ranked games against someone near your rating, or a friendly game with a Steam friend. Ratings live on the Steam leaderboard.
Learn
Ten lessons from the rules to shapes, double threats, defending in the right order, and the renju forbidden moves.
1,680 puzzles across five difficulty levels. Every one was generated by exact search and checked by the test suite, so each has a solution that provably works — no "best guess" answers.
Review any game you have played — step through it against the network's read of each position, and stop at any move to ask the engine what it would have done instead.
Yours, offline
The course, the puzzles, the engine and two-player games need no account, no connection and no sign-in. The engine runs on your own machine — your moves are never uploaded. Your games are saved as a plain text file you can read, keep or delete. Only ranked play needs to be online, and it says so.
In your language
English, 简体中文, Español, 日本語, 한국어, Deutsch, Français, Italiano — the teaching text too, not just the menus.
