Reversi, also known as Othello, is a board game with roots in the 19th century. It was later modernized in the 1970s and renamed Othello. It is a game which is easy to learn, with simple rules and one type of piece, which has a different color on each side. Nevertheless, it is a game of great strategic depth and mastering it takes a lot of study and practice.
The game is played on a board with 64 squares, arranged as 8 columns and 8 rows. The game pieces have the shape of discs which have a black side and a white side. Black always put the pieces down with the black side up, and White with the white side up. Black must always go first. Pieces can only be played on empty squares, and stay on the same square until the end of the game. To make a legal move, the played piece must bracket one or more of the opponent's pieces in any direction between two pieces of the played color. All the pieces bracketed in every direction are then flipped to show the played piece's color. If a player cannot make a valid move he or she must pass. If both players cannot make moves the game ends. The player with the biggest number of pieces wins.
Usually novice players try to maximize their number of disks with every move. But the number of disks is not really important in the beginning and in the midgame. After some practice players realize that not all squares are not created equal, and some are more valuable than others, such as the corners and the edges. Later, they perceive the value of mobility and piece stability. Reverso tries to mimic these three stages with its several levels of difficulty.
Some Reversi/Othello resources: