Changes

*'''"Double-filing"''' - placing two Rooks in line with each other creates a very powerful vertical or horizontal force along that line.

*'''"Double-filing"''' - placing two Rooks in line with each other creates a very powerful vertical or horizontal force along that line.

*'''Forking''' - attacking two undefended pieces simultaneously with one piece of your own.  This forces your opponent to, essentially, choose which piece to sacrifice.  Forking between rooks is a common strategy, especially with a knight.  Forking between a rook and a king is common, too, since the player obviously cannot surrender his King!

*'''Forking''' - attacking two undefended pieces simultaneously with one piece of your own.  This forces your opponent to, essentially, choose which piece he will lose.  Knights are especialy adept at Forking because their method of movement allows them to attack any other kind of piece without being under attack from that piece.  Forks in which the enemy King is one of the pieces under attack are especialy effective because they force the opponent to move the king, leaving no choice as to which piece to move. While the knight is the most adept at forking, all of the other pieces are capable of it.

*'''Pinning''' - this strategy involves maneuvering your piece, so that there is an enemy piece in between your attacking piece and another more valuable enemy piece. This creates a situation in where the opponent cannot move the piece in question without losing the more valuable piece behind it, effectively "pinning" the piece.  A pinned piece can be easily taken.

*'''Pinning''' - this strategy involves maneuvering your piece, so that there is an enemy piece in between your attacking piece and another more valuable enemy piece. This creates a situation in where the opponent cannot move the piece in question without losing the more valuable piece behind it, effectively "pinning" the piece.  A pinned piece can be easily taken.