Cubicle 7 explains why its fantasy RPG based on Warhammer: The Old World will be a separate game and not a line of supplements for its existing Warhammer fantasy RPG, which is called Warhammer Fantasy Role-Play

pcgamer.com:

Games Workshop's return to its original setting The Old World in the tabletop wargame Warhammer: The Old World seems to be working out. They've dropped a hint about adding Cathay as a future army—a plan they'd previously backed out on—and last year Cubicle 7 announced a tabletop RPG to accompany the wargame.

Players of Cubicle 7's Warhammer Fantasy Role-Play 4th edition were a bit surprised by this, given that it's an existing and well-supported tabletop RPG set in Warhammer's Old World. But while that's been hovering around the Old World in the year 2512 by the Imperial Calendar, the Old World wargame is set hundreds of years earlier in the setting's timeline. Still, that's something you could cover with a supplement to the existing game that describes how things were different in the preceding period, right?

Wrong, according to Cubicle 7's CEO Dominic McDowall. In an interview with streamer Great Book of Grudges on YouTube, McDowall explained that, while they considered publishing expansions for WFRP that covered both time periods, they soon figured out it wouldn't work. «I think very quickly we realized that, certainly in the Empire and Bretonnia, any human city has burnt down, what, 17 times?» he said. «There's no people in common. The geography's changed completely, so you'd have to do two books in one anyway.»

Senior producer Pádraig Murphy added that a new RPG presented an opportunity to make something more accessible than WFRP's infamously crunchy 4th edition. «The Old World's a fantastic wargame and it's bringing in new fans who aren't necessarily gonna know who Karl Franz is,» he said. «We want our books to be really welcoming to those people.»

Murphy described the rules as based on a dice pool of d10s, and made them sound low on complexity, but high on danger. «This is a grim and glorious era as we're calling it,» he said. «You're still down in the mud and blood of the Old World, and accessible doesn't mean less lethal, for example. It's still very