Reversi

Place four starting discs in the center of the board in an alternating pattern.

On your turn, place a disc so that it traps one or more of your opponent's discs between it and another one of your discs in a straight line.

Flip every trapped disc over to your own color.

If you cannot make a legal trapping move, your turn is skipped.

When the board fills or neither player can move, whoever has more discs of their color wins.