Othello or Reversi

Objective

Objective of the game is to have the greater # of pieces at the end in your color.

Rules

Figure 1: Starting Position

               
               
               
               
               
               
               
               

1. Black always moves first.

2. If on your turn you cannot outflank and flip at least one of your opponents disc, your turn is forfeited and your opponent moves again. However if a move is available to you, you must play.

3. A disc may outflank any number of discs in one or more rows in any number of directions at the same time(horizontaly, vertically, diagonally). A row is defined as one or more discs in a contiuous straight line.

Figure 2A: Row example.

               
               
               
               
               
               
               
               

Figure 2B: Discs flipped after Figure 2A.

               
               
    >          
    >       <  
    >     <    
               
        ∧ ∧    
               

4. You may not skip over your own color to outflanck an opposing disc.

Figure 3A: Placing a white disc on the red square only out flanks the black squared being pointed to.

               
               
            ∨  
               
               
               
               
               

Figure 3B:

               
               
            ∨  
               
               
               
               
               

5. Discs may be only outflanked as a direct result of a move and must fall in the direct line of the disc placed down.

Figure 4A: Red square is where a black disc is placed

               
               
               
               
               
               
               
               

Figure 4B: Pointed at discs are the ones that flipped.

               
               
               
               
               
    ∧ ∧ ∧      
               
               

6. All disc outflanked in any move must be flipped, even if it is to players advantage not to flip them at all.

7. A player who flips a disc which should not have been turned may correct the mistake as long as opponent has not made a subsequent move. If the opponent has already moved, it is too late to change and the disc(s) remain as is.

8. Once a disc is placed on a square, it can never be moved to another square later in the game.

9. If a players runs out of discs, but still has an opportunity to outflank an opposing disc on his or her turn, the opponent must give a disc to use.(This can happen as many times as the player needs and can use a disc.)

10. When it is no longer possible for either player to move, the game is over. Discs are counted and the player with the majority of his or her color discs on the board is the winner.

NOTE: It is possible for a game to end before all 64 squares are filled.



Strategy

Corners are special and can never be outflanked.

Bad idea to place a disc next to empty corner.