Picking unarmed combat skills in GURPS

 In GURPS, picking weapon skills is fairly easy—figure out what weapons you want your character to use, then buy the skills for those weapons. Occasionally you'll have a weapon that can be used with multiple skills, making the choice less obvious, but most of the time it's very straightforward. With unarmed combat skills, though, the choices get a bit confusing, especially for grappling skills.

In picking unarmed combat skills, it helps a lot to know what tactics are game-mechanically favored. One tactic that works quite well is a grapple followed by the Knee Strike technique. To do this, you need at least 1 point in Brawling or Karate (Knee Strike doesn't default to DX), but you don't actually need a grappling skill—you can just roll against DX for the grapple. For this and other reasons, putting even 1 point in Brawling goes a long way for characters who mostly fight with weapons but want to be prepared for the possibility of an unarmed scrape.

In contrast, following up a grapple with what GURPS calls a "takedown" is usually a bad idea, because if the defender wins the Quick Contest, the attacker falls down! In expectation, this is a waste of a combat turn unless you have a big advantage in ST or skill, or for some reason you really need your opponent on the ground. GURPS Dungeon Fantasy 10: Taverns sneaks in a variant rule where the attacker in a takedown only falls if they lose the Quick Contest by 3+, but this still isn't a great deal compared to attack options that are unlikely to backfire except maybe on a critical failure. Because of this, if you care about being able to put opponents on the ground without hurting them, Judo is vastly superior to Wrestling.

Thankfully, justifying giving a character the Judo skill is easier than you might think. GURPS Martial Arts includes Judo as a mandatory component of, among other things, Late Medieval Knightly Mounted Combat, Longsword Fighting, Fairbairn Close Combat Training, MCMAP, Pankration, Shortsword Fighting, and Combat Wrestling. It's also in the list of optional skills for Masters of Defense Weapon Training, and the description of Italian School Fencing mentions some schools might teach Judo instead of Wrestling. There's a reason I included Judo on my Bow Master template for GURPS Dungeon Fantasy (though in a fuller treatment I would've made a point to strongly recommend Armor Familiarity there, to make Judo useful in heavy armor).

Though I suspect many players avoid it due to the stereotypes involved, from a game-mechanical perspective Sumo Wrestling is a solid alternative to both Judo and Wrestling. Notably, like Judo and unlike Wrestling, it offers the Sweep technique as a non-damaging way to put opponents on the ground. In terms of justifying why a character knows it, any sport involving a lot of shoving and tackling could probably do the trick: Martial Arts mentions "rugby-players-turned-action-heroes", and ice hockey has come up at least once on the SJGames forums. Honestly I would not be surprised if the basic concept of "combat sport where you try to either make your opponent fall, or else force them out of a ring / off a platform" has been independently invented multiple times in human history.

Of Judo, Sumo Wrestling, and Wrestling, Sumo Wrestling is also probably hampered least by No Fine Manipulators, making it a good choice for animal companions. You may not like it, but a paladin's celestial steed having 8 points in Sumo Wrestling is what peak character optimization looks like. (And if it makes you feel better, uplifted police dogs with Sumo Wrestling are canon for GURPS Transhuman Space.)

At first glance, the big selling point of Wrestling is the bonus to certain ST-based rolls, but this only kicks in at the DX+1 level. It doesn't help if you're just looking to buy a grappling skill at DX to expand your combat options a bit (similar to that 1 point in Brawling mentioned above). Plus, this niche can be invaded if the GM allows characters with Judo or Sumo Wrestling easy access to the Power Grappling perk.

The one place Wrestling does shine is if the main draw of grappling skills for you are the Arm Lock, Head Lock, Finger Lock, and Leg Lock techniques. Judo gets these too, but since Judo is a Hard skill while Wrestling is merely an Average skill, Wrestling may be the better choice if you don't mind missing out on the techniques that have no Wrestling default. Unfortunately this means missing out on Judo Throw and Sweep, but you can still use Throws from Locks (Martial Arts pp. 118-119) if you need an effective (if not exactly non-damaging) way to lay someone out flat using your grappling skills. In other words, contrary to what those familiar with collegiate wrestling might assume, Wrestling in GURPS isn't at all about merely making your opponent's shoulders touch the mat!

There are a handful of techniques that are actually exclusive to Wrestling (like Scissors Hold and certain cinematic techniques), so in some sense a well-rounded grappler is "should" have both Judo and Wrestling. Unfortunately, the way GURPS skills work tends to discourage this, much as it tends to discourage putting a lot of points into multiple very similar weapon skills. If you want to play an all-around grappling master, you'll most likely be fine with a high Judo skill combined with Power Grappling.

(As an aside, yes Power Grappling is an amazing perk for many builds. It can be tempting to think it can't possibly be meant to work by the exact letter of the rules, but on the forums Kromm has confirmed that it "works exactly as the written logic suggests".)