OOC: I updated the maneuvers to include the full description of Head Lock since Jade is doing this maneuver. See the Rules UPdates thead to read it:
link to a message in "GURPS - Masters of the Matrix"
Here it is again:
Head Lock (Hard) Def: Judo-4 or Wrestling-4
Prereq: Judo or Wrestling; cannot exceed prereq lvl
This attack consists of putting the target's head in a lock, similar to a choke hold, but holidng it in such a way that the target can be thrown while using the neck as the axis of the throw - which will almost certainly break the target's neck. After Grappling the foe, the attacker must roll against Head Lock to grab the neck (the target can make any Active Defense against this; PD does not protect). On a success, the target's head has been put in a lock.
The following round, the attacker can try to either Choke the victim (treat as normal Strangling roll), or he can throw him; the throw is resolved as a Quick Contest between the attacker's Judo or Wrestling skill and the defender's ST, DX, Judo or Wrestling, whichever is highest. If the attacker wins,the target takes swing damage (plus a bonus equal to 1/8 Wrestling or Judo skill) to the neck, which is multiplied by 1.5. If defender wins or ties, no dmg is taken and the victim can try to Break Free.
See Neck Snap maneuver for lasting effects of neck damage.