Felon said:Yeah, someone please elaborate. I'm really not getting how slapping the label "zone" on a pool of acid is in any way adding content to my game that didn't exist before. It sounds more like general advice than an actual codified rules subset ("add interactive elements to your battlefield like falling rocks and pools of lava").
I don't actually have time to expand on this today but there are specific rules for each zone -- and guidelines for designing new zones. It's certainly a lot more than just hazards or weather conditions as described in the DMG.
Maybe Mike Mearls will swing by and give a detailed description. Or you can ask at the Iron Heroes website.