View source for BlizzCon 2009 Diablo 3 Official Preview

==Environmental Interaction==

Diablo III will present players with dynamic, interactive environments and set pieces such as crumbling walls or collapsing bridges. What kind of cool stuff should players look out for in the BlizzCon demo?

'''Jay Wilson:''' There are about a dozen randomized events that players can stumble upon in the demo. We like to do some foreshadowing, dropping some clues about what's waiting for players a little ahead of time, but with randomized environments that's not always possible. We do have a lot of cool scripted sequences in the demo though. To give you an example, in one of these encounters you'll find a man in the desert who's trying to warn you of Dune Threshers in the area...mere moments before one of the creatures bursts through the sand and devours him.

There is also another fun sequence where you're in this underground dungeon that's starting to collapse, so you have to make your way out in time -- but there is a lot of treasure down there, so you have to make a call whether you want to risk getting crushed for some sweet loot or play it safe and pass on some potentially awesome treasure.

In terms of quests, there is a main quest and 12 to 18 side quests in this demo, which is a lot. There's also a storyline in there that ties into a piece of lore you can find on the Diablo III website, "Encounter with Burrowing Death." I think players who read the piece will get a kick out of finding this story in the demo.