The game begins with
four pieces placed in the center of the board
in the position shown below on a reversi board consisting of 64 squares in an 8x8 grid.

Finish the game with
more pieces of your color
than your opponent.
Place a piece on an empty square so that it
traps one or more opponent pieces
between your new piece and another one of your pieces in a straight line.
All trapped opponent pieces are
flipped to your color
. You can capture in horizontal, vertical, and diagonal directions, including multiple directions at once.

If you have
no legal move
, you must pass.
The game ends when
neither player can move or the board is full
. The player with the most pieces wins.