Abstract: There is a lock for a gaming machine or other device. The lock has a plug 3 rotatable in a cylinder 1 between latched and unlatched positions. There are rolling members 9, 9A which at the latched position are radially displaceable within aligned plug and cylinder recesses 10, 11 between an outer locking position wherein said rolling member extends across a shear face 10A separating said plug 3 and cylinder 1 to hold the plug in the latched position and an inner unlocked position wherein the rolling members 9, 9A are substantially within the plug recess 10. There is a plunger movable axially within the plug 3 between a first position wherein the rolling members 9, 9A are retained in the locking position and a second position in which the rolling members 9, 9A are movable inward from the locking position to the unlocked position to allow rotation of the plug 3 from the latched to the unlatched positions.