What is Wrist Lock in BJJ?

A wrist lock hyperextends or rotates the wrist joint beyond its natural range of motion. Wrist locks can be applied from many positions and are often surprising because opponents do not expect them. They are legal at blue belt and above in IBJJF. Wrist locks are sometimes considered "dirty" or sneaky, but they are legitimate submissions. Common setups include catching the hand during grip fighting or when the opponent posts.