GURPSよろず

Elbow Strike
Average
Defaults: Brawling-2 or Karate-2.
Prerequisite: Brawling or Karate; cannot exceed prerequisite skill.

You can jab an elbow into an enemy behind you in close combat. Roll against Elbow Strike to hit. There’s no modifier for not facing him, but add an extra -1 if you target a specific hit location. A hit inflicts thrust-1 crushing damage, plus skill bonuses. Treat an elbow to someone in front of you as a punch.
Elbows are short-ranged and hard to hurt. You may not select All-Out Attack (Long) (pp. 97-98). Hurting Yourself (p. B379) applies, but damage is 1/10 of what you roll – not 1/5 – and both it and injury from enemy parries affects the arm, not the hand.