Over on the SJG Forums, I had a very productive interchange with Gef, a poster who wanted to know more about how grappling works using Technical Grappling, and asked for an introductory paragraph something like this:
Grappling generally consists of an attack to establish a hold (which need not be an actual grasp), with a roll analogous to a damage roll (and based on thrust damage) to establish how good a grip the grappler achieves, expressed as Control Points. These Control Points do two things: First, they impose a penalty on the target’s ST and DX, and second, they may be spent to cause damage or pain, or to force an opponent into an unfavorable position. Unlike damage, Control Points persist until spent, continuing to penalize ST and DX, unless modified by the action of the attacker (attempting to strengthen his grip) or his target (attempting to break free).–Gef
The first thing you do before you even use the rules in TG is you have to attack someone with a grappling skill and hit. This is an attack, using DX, Judo, Sumo Wrestling, or Wrestling. You can also use Armed Grapple, a technique that defaults to any appropriate melee weapon skill-2. Some weapons such as lariats or (I think) nets attack to entangle at full skill.
Referred Control and Whole-Body Actions: Always use the most severe penalty from any body part involved in an action. Using both arms or both legs always involves the torso, so apply the harshest penalty from any of those locations. For skill use, apply the worst of the whole body penalty or that of any limb used to perform the skill.
Note that this paragraph has been changed since my original post, and I’ve updated it. It was clarified as a drive-by making an errata to this section on pp. 5-6, and I took the opportunity to clarify that yeah, skill use suffers the worst of the whole-body penalty or a penalty to a grabbed limb. Much nastier and more believable that way.
Step Three: Do More Stuff
Once you have that initial grapple, you have a choice. You can try and do something fancy with it, or you can do moar grapple! You can grapple again, to rack up more Control Points and improve your situation. This is an attack, but this time, the rules for fighting in Close Combat apply. Your foe will have a harder time using Block, for instance. He’s also penalized by whatever control you have achieved, and his movement and dodge are extra-hampered.
You can do all sorts of stuff with this, including shifting grapples around, or even trying to trap his limbs under yours, good for representing a good side mount or triangle choke.
In any case, once you have that grapple, you can then start to do techniques with it. Most of those are Quick Contests of a combat skill, DX, or Trained ST (ST with a bonus like that given for Wrestling, but bigger if you’re more skilled) vs. the defender’s best of several options, depending on the technique. This can be DX, ST, a combat skill, even Acrobatics or Breakfall, and sometimes, HT.
If you’re rolling vs. HT, you’re probably rolling to not get injured. One neat trick, though, is that to have a big injury, you must have lots of Control in most moves. Your injury is limited by the CP you have, and you must spend those CP when causing injury. Damage by delayed gratification.
The most common one for Wrestlers or Sumo Wrestlers (and some Judo and weapon guys too) will be the generalized version of Takedown (p. B370), now called Force Posture Change.
When doing grappling Contests, you may spend your Control Points to make it harder for your foe to succeed in his roll. You may not spend them to make your own grappling skills better, and this is important. Your skill, after penalties, matters. You have to perform some moves correctly and beat your foe’s ability to resist in order for them to work. Others, you just have to win the contest.
It’s really not as complicated as it may sound.
Step Four: Finish Him!
The last step(s) are really just situation dependent. Do you want to kill your foe? Cripple him? Does the match end when someone’s taken down (like Sumo)? Are you just trying to touch his shoulders to a flat surface like in Collegiate Wrestling (see p. 45!)?
How you finish will depend on your goals. A GURPS “Pin” (p. B370) is gone from the rules. You do that by accumulating enough Control Points to render all of your foe’s rolls moot, easily foiled by his failure and your own defenses.
There’s lots of detail and rules in the book. But the basics are exactly the same as regular GURPS combat. Make an attack (and “breaking free” is now also an attack, so that’s not something unusual), your foe defends, and if he fails, you roll “damage” in the form of Control Points. If you want to do something fancy, this will almost always be resolved as a Quick Contest of skill, where margin of victory and Control Point spend will tell the tale.
In the words of Laufey: “I . . . accept.”