Reversi

1. The board has 8 by 8 squares. The game starts with 4 discs in the middle: 2 black and 2 white, corner to corner.
2. Black moves first. Then the players take turns.
3. Put a disc next to a disc of the other color, so that a straight line of their discs lies between your new disc and another of yours: across, up and down, or on a diagonal. Every disc in that line turns to your color.
4. One disc can close lines in several directions at once. All of them turn.
5. A move must turn at least one disc. With no such move, you pass, and the other player moves again.
6. The game ends when neither player can move. The color with more discs on the board wins.

The dots show where you can move. Play the computer at Easy, Medium or Hard, or choose 2 players and take turns on one phone or computer. Against the computer you play black and white in turn, since black always starts. On a keyboard, move with the arrow keys and press Enter.

• Take the corners. A disc in a corner can never turn over, and it makes the edges next to it safe.
• Stay off the squares next to an empty corner, most of all the diagonal ones. A disc there often hands the corner to the other player.
• Count moves, not discs. Early in the game, fewer discs often means more choices later, while the other player runs out of good moves.
• Keep your discs together in the middle, so the other player has few squares to play.
• Near the end, count the discs. The last moves turn over the most, so the lead can change at once.