Morkus from Orkus
Then why wouldn't they just say that the editions are compatible with one another instead of the new one being backwards compatible, and not backwards compatible with the older books, but rather just with the 2014 adventures?Why wouldn't it? We've seen basically zero actual rules changes. The basic math of the game isn't changing. None of the combat mechanics or skill mechanics are changing. Why wouldn't you be able to run a newer module with a 2014 core set?
I expect we will have to do work to make the new adventures work with the old rules. Perhaps not much(or maybe there will be a lot), but we will have to do it so there isn't forward compatibility.