Exotic Hand Strike is found on MA71 of GURPS Martial Arts
It somewhat resembles Lethal Strike in that it can make an attack potentially more damaging in exchange for a skill penalty.
In this case however it is +1 to damage (stays crushing) for -1 to hit, whereas lethal strike actually took a damage penalty (and -2 to hit) for the benefit of converting to piercing, which could better target the vitals, eyes, and had the benefit of a minimum damage of 1 (crushing is 0)