Bill Zebub
“It’s probably Matt Mercer’s fault.”
Yup.
It uses the core D20 system mechanic of d20 + mods vs a DC, but that originated in 3E. Same with the ability score bonus scale. Which I think Kelsey chose over the B/X bonus scale very deliberately as part of her advancement system, for how it works with Talent rolls and enables a bit of "2-for-1" advancement at lower levels.
Just about the only things it lifts directly from 5E are the rolling with advantage/disadvantage concept, and HP not going below 0 (the game has no negative HP, like 1E, 2E, 3.x, and 4E did).
...and I believe Mike Mearls has acknowledged that he got the idea for Advantage/Disadvantage from The One Ring. I can't cite a source for that, but TOR did pre-date 5e.







