Get to Know About Reversi
Reversi uses an eight by eight grid with two sided disks. One side is dark and the other is light. You pick a side and try to finish with more of your disks showing than your opponent. The game begins with four disks in the center in a checker pattern and the player with dark moves first.
On your turn you place a disk on an empty square that traps a straight line of opposing disks between your new disk and another of your color. You flip every trapped disk in that line. Lines can run horizontal, vertical, or diagonal. Each move must flip at least one disk. If you have no legal move you pass and your opponent plays. The game ends when the grid is full or both players have no legal move. The player with more disks showing wins.
Corner squares decide many games because disks placed there never flip. Edge squares help as well because they reduce the ways a line can trap you. Aim to keep many legal moves and leave the opponent few. People call this mobility. It means the count of moves you can make. Early in the game avoid big flips that open easy paths to corners for the other side. Steer play toward the center until you can claim a corner or force a pass. Near the end count empty squares in each area and try to take the last move there to gain extra disks.