Originally Posted by Merry Mayhem

Grease is flammable (From Sage Advice, JC states it is not)

I mean, if we're talking about differences between BG3 and the PHB, which is the title of this thread, then this one doesn't count. The PHB absolutely does not say that Grease isn't flammable, it historically has always been flammable, and many people disagree with the Sage Advice. If I had to guess, between the DMs that don't know/care about Sage Advice and the ones who think this particular one is wrong, I'd venture that at least 3/4 of tabletop 5e games play with flammable Grease.