Ruin Explorer
Legend
I don't think that's as much the system as the characters, though.But we also know their numbers go down when they play one/two shots in other systems.
The people follow the actors building up specific characters, and when you play a one-off, you get the actor but the familiarity of your beloved and emotionally-connected character they play.
If, and obviously this is a huge if, they are at odds with WotC (unlikely I think), and WotC decides to go full self-immolation (also unlikely) by trying to push OGL 1.1 with general deauthorization, all CR would really have to do would be to say "Oh we're actually going to do Critical Role Season 4 after all, and it's in this system", and I think 90%+ of their audience would be some busy getting excited about another season that they wouldn't care about the system.