The Joker, Jack Sparrow, Murdock...you ever wanted to play that guy, the crazy bastard who comes up with quirky schemes in the middle of combat and then some how pulls them off? Besides buying a lot of Luck there are a couple of other ways you might be able to pull it off.
The Big Crazy Plan That Should Not Work
"You and I remember budapest very differently" - Deceptive Attack allows a character to take a -2 to their attack roll to give their target a -1 to defend against that attack, but what about planning for a larger battle? Allowing a "Deceptive Plan" option for Tactics or Strategy might be a way to go. If the GM allows then each -2 penalty accepted on a Tactics rolls gives the opposing side a -1 to their roll. If using the rules from GURPS Martial Arts (p. 60) each -2 penalty you accept on your roll gives you either one reroll using the abstract rules or one move if using the mapped rules - even if the character with the Deceptive plan fails the contest overall, he can use these rerolls/moves. He's essentially trading away victory (assuming he has a high skill) for some surety thanks to his tricky methods.
New Character Trait
Reaction Bonus and Alternative Benefit: None.
Notes: This trait's point cost was calculated as follows per level: DX +1 (Only for deceiving others, -70%) [6/level]; IQ +1 (Only for deceiving others, -70%) [6/level]; HT +1 (Only for deceiving others, -70%) [3/level]. As the IQ increase raises Will and Per, it affects skills based on those scores, too.
I didn't come up with Deceptive Strike, but it sure does belong in this post, The_Matrix_Walker over on the forums posted this technique in this post of this thread. I've modded it a bit for my campaigns - but it was his idea, not mine - though Quicksilver Strike is one I came up with for use in my campaigns.
Statistics: Opponent's Defenses; Dodge -2 Penalty (-4 to default), Parry -2 Penalty (-2 to default), Block -2 Penalty (-2 to default) with the drawback "Must Roll vs DX or fall on a miss. (If a combined with a maneuver (ie. kick) that has this drawback already, apply a -1 Penalty to the existing DX Roll)."
Prerequisites: Any melee weapon or unarmed combat skill; cannot exceed prerequisite skill.
Use this technique, instead of your skill when making a Move and Attack (p. B00) with it; ignore the skill cap of 9. This is a cinematic technique.