Back in my 3e days, I was unsatisfied with GURPS combat as written. I didn't dislike it, but I felt like it could be streamlined and improved to be a better combat system. I gave it a go.
I bring this up because Jeffro said
"If you haven’t designed a completely new combat system because you knew you could do it better, then you’re not old school."
I'm pretty old-school, I guess. I didn't design a completely new system, but I did say, "This system could be redone from ground-up principles to make it all smoother." That and I'm old school because I was old*, and played D&D at school on lunch break.
The system I came up with I saved in a document called, "UCS" for "Unified Combat System for GURPS." Here are some highlights:
- Multiple Attacks were -4 per additional attack, with a -1 to the defender if you used two different attacks instead of the same one twice. There wasn't any hard cap to multiple attacks that I can recall (or find in the document.)
- I had a basic tradeoff system implied by the rules as written:
"Universal Modifier – the basis of all modifiers in combat is +4/-4.
+4 to hit = 1 attack = 1 feint = +2 to defend = +2 to damage.
All Defenses together – regardless of total – can be traded for a net +4 bonus. All attacks together – regardless of total – can be traded for a net +2 bonus to defend.
+4 to hit or +2 damage = +2 to ST rolls as appropriate. +4 to skill = +4 to DX/skill rolls as appropriate."
- There was "All-Out Move" for people willing to trade their defenses for movement. Usain Bolt doesn't think about Dodging, which is why he gets to move faster than your guy.
- I cut down a lot of the options available to single mechanics.
- I cleaned up those awful, awful, awful 3e Manuevers (now called Techniques) which broke turn order or implied you could attack or move on an opponent's turn or split up your turns. Riposte, I'm looking at you.
- I cleaned up Spinning Strikes, too, and made them into exactly what you see in GURPS Martial Arts. Not a mistake. I went to this document, I'm sure, for my draft look.
We ran a big playtest battle once with a subset of my players. We used their PCs from our regular GURPS-based fantasy game. I distinctly remember one of my players ran his wife's fencer in the system, and cleaned house with her. He stacked up attacks and feints and turned her dominant DX and skill into a fight winner. Overall, I remember being very pleased with how it went. We didn't immediately adopt it, but we talked about it and we started to use little pieces of it.
We only did the one test, but it went well. As I was tinkering with it, though, I got the fateful email from Sean Punch asking me, "Do you want to write a book?" That book was GURPS Martial Arts, and I got a peek at GURPS Basic Set fourth edition. Having seen 4e, I realized two things:
1) I needed to play with those rules immediately, to help me writing GURPS Martial Arts, especially since I decided to move to Japan even as this all went on.
2) My rules were remarkably close to 4e's rules. I still think I did bits of it better, in the sense of "better for me." But I missed a few tricks that 4e included, like Deceptive Attack.
It was a lot of fun doing that document. I won't share it because it contains a lot of block text copied from GURPS Basic Set (3e), since I wanted a one-stop document for rules during our testing and playing. Circumstances altered the need for it, but the idea of "boil it down to only a few tradeoffs and modifiers" really stuck with me. It's why so many of the rules I helped contribute to GURPS seem to have legs, I think. They work because they're just clear statements of a combination of tradeoffs based on fundamental principles that underlay the whole. This is as much a rough draft of my 4e thinking as it was a real combat system, looking back on it from 13 years after I last modified and hit "save" on that document.
* I'm younger than that now.