GURPSよろず

Ear Clap
Average
Defaults: Boxing-3, Brawling-3, or Karate-3.
Prerequisite: Boxing, Brawling, or Karate; cannot exceed prerequisite skill-1.

This is an attack on your foe’s ear using a cupped or open hand. The goal is to pop his eardrum, stunning and deafening him. You must be in close combat and have at least one free, empty hand.
Roll against Ear Clap to hit. Your opponent may use any active defense. If the attack succeeds, it does thrust-3 crushing damage plus skill bonuses. In addition, roll a Quick Contest: Ear Clap vs. the victim’s HT. If you win, your target is physically stunned (p. B420); he’s also at -1 DX and deaf in one ear (treat as Hard of Hearing) for 1d seconds. On a critical failure on the HT roll or critical success on Ear Clap, the victim must roll as if for a crippling injury to see how long he’s partially deaf; see p. B422. Permanent harm is possible!
Ear Clap works best if you box both ears simultaneously. To do a double Ear Clap, you must have two free, empty hands and use All-Out Attack (Double) or another form of multiple attacks. Dual-Weapon Attack with the appropriate unarmed combat skill is one option; add the penalties for that technique to Ear Clap to determine effective skill. If only one hand hits, resolve it as above. If both hit, roll one Quick Contest. If you win, your victim is deaf in both ears (treat as Deafness) for 2d seconds. Once again, a critical failure on HT or critical success on Ear Clap indicates a crippling injury that could become permanent.