This page assumes that the reader has GURPS Martial Arts, Second Edition; if you only have the first edition that should be adequate. If you have neither book this page is likely to be very unhelpful to you!
Semi-Off-Topic Disclaimer: In daily life I am not particularly expert in unarmed combat - my stepsister Kim Messer is the real martial artist of the family - so some oddities may have crept in during the design process. Errata will be fixed as discovered.
Bloody Hand is a martial art style originated by Reptile Men; it is unlikely to be taught to any of those annoying mammals, who don't even have claws. It may not fit in some campaigns.
Some of the more fractious bands of Reptile Men developed highly sophisticaed combat arts in their various dominance rituals; they tended to be stylized and nonlethal (contrast Boxing with Brawling). In time some Reptile Men saw the utility of a scientific fighting art and developed the Bloody Hand style.
It is not the most sophisticated style but it is an effective one, particularly since it's used by Reptile Men! In a cinematic game the lack of mystic abilities will show, but in a realistic one a human martial artist will likely find out why going hand to hand with a Reptile Man is a bad idea...
The more artistic Fighting Hand style is still taught; simply replace Karate and Judo with Karate Art and Judo Art.
The War Claw style has some historical connection to Bloody Hand but is more vicious.
Primary Skills: Karate
Secondary Skills: Judo
Optional Skills: Acting, Psychology, Tactics
Maneuvers: Back Kick, Hit Location, Hook Kick, Kicking, Elbow
Strike, Ground Fighting, Jab, Riposte
Cinematic Skills: Blind Fighting, Immovable Stance
Cinematic Maneuvers: Roll with Blow
This is the hand-to-hand combat art of the Ichinohei Ninja Clan. In all likelihood, there were as many branches of ninjutsu as there were ninja groups; one reference claims that once over 70 families were practicing the profession. The style of taijutsu (meaning 'body combat art') presented here is one plausible variation, as adapted to the 20th Century -- for another ninjutsu style, see GURPS Martial Arts.
Acquiring this martial art will not make a person a ninja; he would just fight like one. Guns are not mentioned here, nor are explosives; modern weapons are another subject entirely, and one a proper ninja would investigate thoroughly. (Everybody uses firearms, and tasers, mace and other recent developments are within the ninja's realm of interest.) Acting, Forgery, Fast-Talk, Disguise, Detect Lies, Sex Appeal and Savoir-Faire are all skills used by ninja but not taught in the dojo.
Medititation is taught to interested students, but is considered a normal skill here. The Trained by a Master advantage is available to clan members.
Ninja, of course, have spent hundreds of years lying to people about what they can do. Anything on this list might be false!
Primary Skills: Karate, Judo, Stealth and either Knife or Staff.
The student must also take two from Climbing, Jumping, Running and Swimming.
Secondary Skills: Whichever weapon was not taken earlier, and
at least two of Blackjack, Blowpipe, Garrote and Knife Throwing. The two
non-weapon skills become Secondary. Three from should be chosen from
Acrobatics, Body Language, Breath Control, Camouflage, Escape, First Aid,
Tactics, Throwing.
Optional Skills: Any of the skills above. Fast-Draw (any),
Hypnotism, Meditation, Off-Hand Weapon Training (any of the above
weapons), Parry Missile Weapons, Philosophy (Confucianism or Buddhism),
Yin/Yang Healing. Any of the following weapons (although they are of
limited use in the modern day): Axe/Mace, Bow, Shortsword (for Ninjato),
Flail (for Nunchaku), Jitte/Sai, Katana (go join a Kendo school), Kusari,
Short Staff, Shuriken, Spear.
Maneuvers: Aggressive Parry, Arm Lock, Back Kick, Breakfall,
Disarming, Ear Clap, Elbow Strike, Feint, Ground Fighting, Head Butt, Hit
Location, Knee Strike, Kicking, Sweeping Kick
Cinematic Skills: Body Control, Breaking Blow, Invisibility
Art, Kiai, Light Walk, Mental Strength, Power Blow, Pressure Points.
(Meditation is classified as a normal skill and is on the Optional Skills
list.)
Cinematic Maneuvers: Dual Weapon Attack, Roll with Blow