[vicky_molokh]

Q: Under Basic rules, which unarmed skills / attacks suffer from off-hand penalties / need OHWT?

A:

Originally Posted by Kromm

Just to be clear: There is no "off" hand in unarmed combat in GURPS. The Basic Set failed to make this as clear as it could have, hinting at it in a few skill descriptions but not generalizing it. Martial Arts makes it far clearer. Claiming that there is an "off" hand for the purposes of unarmed combat is fine as a house rule, but definitely not what the entire body of rules published to date supports.

Originally Posted by Kromm

The Karate skill states "Roll against Karate to hit with a punch (at no -4 for the 'off' hand)." When using equipment of some sort, read the description carefully. If that gear is a glove (e.g., cestus, myrmex, or sap glove), or explicitly enhances punches (like brass knuckles or anything with the "Hilt punch" note), you're throwing punches and may ignore the off-hand penalty. Otherwise, the item deals a weapon blow – not a punch – and attacks and parries are considered armed. In effect, you can claim either the benefit of no off-hand penalty (because you're punching with Karate) or the benefit of no risk to your hand (because you're using a weapon, not your hand), but never both. The Karate damage bonus has nothing to do with where this line is drawn; that bonus applies "when you calculate damage with Karate attacks," which is simply any attack that rolls against Karate to hit.