The Lock Grip is about the first move a cheat learns.  The idea is to hold and shake two dice convincingly without them turning in the cheat's hand.  Study the diagram and see how they are held.  The two dice rest in the bend of the two middle fingers.  The forefinger and the smallest finger stop them rolling back and forth, while the thumb stops them turning along the other axis.  The sound of the rattle produced is known as cackle.  The knuckles of the two middle fingers may look a bit awkward because they are protruding, but this can be hard to spot when the hand is in motion.  Try and detect this move by watching how the cheat picks up the dice.

For information on which way the dice should be held in the hand, see Dice Setting.  Controlled throwing techniques (like The Blanket Roll and Rhythm Rolling) use the Lock Grip and setting techniques in combination to affect the roll.