Remember when I said it had been decades since I ran GURPS? It is entirely possible that I unintentionally duplicated their system. Hell, I may have unconsciously used some of their ideas, since it was a year or so after I left the group that was running GURPS that I started building my system.

I'm looking this up as I'm typing here, and it seems the difference in resolving an encounter via dice is exactly the same as contests.

Yeah, I use different traits and skills, and the 100 scale on everything is different, along with a lot of homebrew magics and the world itself. But that mechanic is the same, and it's the core mechanic of the system.