Instructions
Let your opponent be white, thus having the first move. If your opponent is a beginner, this may give him a false sense of security and make it easier to lure him into the trap.
Wait for your opponent to make the first move. If she moves her king knight pawn two spaces up or the king's bishop pawn a space, you're in good shape.
Move your king's pawn ahead. Most players move it two spaces, but one will work just as well.
Wait for your opponent's second move. If he makes the other of the two moves mentioned earlier (king's bishop pawn up a space or king's knight pawn two spaces), you have him.
Move your queen four spaces diagonally (to king's rook four on the board). White is in checkmate because your queen is directly attacking the queen, the king cannot move out of the line of attack and no other pieces can move to block the queen.