Reversi

How to play Reversi

Reversi is played on an eight-by-eight board from the usual four-disc start. Every move has to outflank at least one straight line of the opponent's discs, and every line it outflanks flips to your colour. A side with no legal move passes, and when neither side can move the most discs wins.

The legal squares are marked with how many discs each would flip, which is exactly the number that tempts you into the wrong move: grabbing discs early hands your opponent the mobility, and the squares beside the corners give the corners away.

The ladder has three opponents. Juno simply grabs the most discs, Corvid weighs corners and mobility three moves ahead, and Nyx searches four moves ahead and plays the last eight empty squares out exactly. A loss costs one of three lives; a drawn game is replayed.

Objective

Finish with more discs than three opponents in turn.

Features

• Full Othello rules with passes and the four-disc start
• Legal moves marked with how many discs each would flip
• Three opponents from disc-grabbing to corner-weighing search
• An exact search of the final eight empty squares at the top rung
• A live disc count and territory bar

Scores are saved in this browser only. There is no global ranking and nothing is uploaded.