Like most things in life, rapidity is often advantageous. In combat, speed is almost all that matters. Put bluntly: Speed kills. In GURPS, if you are fast enough, skilled enough, or coordinated enough you can pull off some amazing things. The Basic Set combat system gives you several “standard” methods of attacking (All-Out Attack, Attack, and Move and Attack), while GURPS Martial Arts gives us a few more (Committed Attack and Defensive Attack). Of course, there are several combat options too: Dual-Weapon Attack, Rapid Strike, and Flurry of Blows. And let’s not forget the various traits you can buy to enhance the number of times you can attack: Combinations, Extra Attack, Trained by a Master, and Weapon Master. So what’s the best way to go? Well, I’ve got a few ideas.
Extra Attack, Revisited
Extra Attack costs 25 points per level and for human(oid)s you usually need the Multi-Strike enhancement to get the full use out of levels higher than the first. What’s more, it’s usually better to invest in high skill and take a penalty to your attack roll. So something like Extra Attack 1 (Multi-Strike, +20%; Single Skill, Broadsword, -20%)  has a high point disparity when compared against a technique for buying off the -6 penalty to Rapid Strike . Now, you might consider comparing it to a +6 to skill , but that level of skill lets you do a lot more than just attack. Were I redesigning the Single Skill limitation I’d probably use something closer to the following than what’s listed in the Basic Set.
[Text is as per Single Skill from GURPS Powers (p. 49)],
At the GM’s option, if a particular form of attack is more limited than it appears, add another -10%, while if it’s broader add +10%. For example, “All Unarmed Attacks” might be worth -10% because while it does limit your options, it’s still quite useful.
• Broad: Your advantage only applies to a particular skill of your choosing or related forms of attack (e.g., Karate or all sword attacks). -20%.
• Moderate: Your advantage only applies to a particular type of attack or a subset of a skill (e.g., bite only or Wrestling Grab). -40%.
I’m Better When I Move
Speed kills, but so does tactical advantage. Being able to maneuver or outmaneuver your opponent(s) can often be as deadly as attacking faster than your target can defend against. To that end Move and Attack is highly useful and stacks with most advantages, options, or techniques. Actually being able to buy off the penalty is best represented as a technique.
Prerequisites: Any Melee Weapon or Unarmed skill and Trained by a Master, Weapon Master, or Unusual Training.