How it works

Reversi is played on an 8-by-8 board. The game starts with four discs in the center, and Black moves first.

On your turn, place a disc on an empty square that traps at least one opposing disc in a straight line. The line can run horizontally, vertically, or diagonally. Any trapped discs flip to your color.

The game highlights legal squares so you know where a disc can be placed. It does not rank the moves or tell you which one is best.