I know that I cannot write Adventures for Star Trek, or Dune, or Fallout, etc., because none of these lines are included in the World Builders programme.
But am I correct, assuming that I can use any mechanic of any 2d20 game and use it with my own creation – despite they’re not included in the SRD? Can I introduce “extended consequences” (as introduced in the Star Trek Adventures Gamemaster Guide), or use Dune’s duelling or intrigue systems, or STA’s scientific method?
I can, as long as I re-phrase explanations (and maybe also technical terms?) to fit my system/world – right?
As far as the debate on game licencing goes nowadays the consensus seems to be that you can’t license a game mechanism so it seems that you can use any mechanism you want. But as they say it isn’t a legal advice.
LegalEagle on Youtube made a video on it (but he also say it isn’t a legal advice)
Since it’s about another game license I will not post a link here