Once again, my creativity is roused somewhat by a thread on the forums. This one’s on snakes and grappling.
One might imagine that I have something to say on this, being the GURPS grappling guy. One would be right.
The Raw Way (mostly)
If you have a snake that attacks by constriction, you have a snake that wants to make grappling attacks. While RAW I believe can be construed to allow a torso-based grapple if you have Constriction Attack and Double Jointed (see Martial Arts, p. 116), I would smack such legalisms on the nose with a rolled-up newspaper.
The snake first bites to grapple. This is a grappling attack with the mouth. You have to look for it, but a bit is a one-handed grapple (MA, p. 115 in the box for Teeth). You attack at full location penalties. If your foe fails to defend, you have him by the mouth with the equivalent of one hand. You also do thrust-1 damage. The foe is, technically, “grappled” at this point, and at -4 to DX . . . but the one-handed nature of the attack makes it easier to break free.
The next chance you get, you can follow up with the body grapple, and this one is at full ST, considered a two-handed grapple. I don’t know offhand if real snakes let go with the mouth once they have constricted the prey, but in any case, I’d just treat the snake as having its full ST.
Once that grapple occurs, the snake will apply his Constriction Attack, using the Bear Hug technique (MA, p. 117) to crush the foe to death. If the foe is too large to simply crush, the snake will suffocate if it can.
Seems to me that many snakes will actually buy a Combination (MA, p. 80) to bite and grapple with the torso as a bought-off Rapid Strike. I’ve seen video of ball pythons doing their thing, and that “bite and wrap it up” thing is fast.
There’s actually an entry on p. 44 for Constrictor Snakes. Bite to grapple and do thr-1 Control Points (1d-1 for the python in the Basic Set). Follow up with another grapple (using the snake’s inherent Wrestling skill, which is not bad) using the body, but Constriction Attack does double the usual CP for that creature’s ST. Since a python is ST 13, that’s 2d CP, which will get even a reasonably strong adventurer in trouble in a few seconds.
Once enough CP are accumulated, the snake will begin the process of spending them to crush the victim, then re-acquiring them through a grapple, then spending them for more crushing.
This is not the most elegant mechanic, though it does the trick. +Peter V. Dell’Orto and I did come up with a better one. Hopefully one day it will see daylight.
I introduced a quick-and-dirty alternate for using Control Points but not bringing in all of TG late in July called Condition-based grappling, which took a concept that could have been done better in the DnD Basic Rules (5e) and did in GURPS what I thought could have been done (and maybe will be or has been in the PHB and DMG; we’ll see when they come out) in that system.
In any case, it’s easy. Roll for the bite. Assess CP. As soon as you can, roll for more CP by attacking with the torso. When you have your foe Restrained, start crushing.
The condition-based grappling could use some expansion for stuff that’s not just holding on and applying penalties. The Control Point mechanic can be leveraged in a few easy ways to execute various grappling techniques without the detailed tracking that the full system has.
But all in all, snakes and other grappling monsters – such as something with, say, ST 21 tentacles with gripping mouths on them! – can and should be terrifying in GURPS. Right now they can be somewhat meh.
I think that TG really shines for such critters. That ST 21 bite will do 2d CP right off the bat, and that tentacle with Constriction Attack will accumulate 4d CP with every attack (and it may well AoA(Double) for 8d CP each turn; an average of 28 CP per second), which is enough to hit the max CP threshold for most creatures. With the right skills, that is a huge amount of crushing damage every turn.
Anyway, the rules are a bit scattered for both RAW and TG; you have to look through three books (or at least two, Campaigns and Martial Arts, with the third being Characters) even in RAW.