Diablo III Interview

While it's billed as an interview, this piece on Complex Magazine is technically a smattering of twelve comments made by Diablo III lead gameplay designer Kevin Martens about the game's classes, skills, and overall design. Still, it's an interesting read if you're willing to flip through all the images:
Martens said Diablo 3's combat will be even more tactical than in the previous games in the series. "Primarily because the classes are completely different, we did want the combat to feel very much the same, but we wanted it to have a higher level of tactics," he said. "So we spent a lot of time working on the monsters not just the monsters themselves and their abilities, but the way that they work together."

That'll require players to think on their feet especially when coupled with the game's high degree of randomness.

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Diablo 3 will add even more randomness than the previous games in the series. "We don't place a lot of things by hand in groups that are pre-planned," Martens said. Monsters will rarely work as a team that's not in their AI design.

"We don't need that," Martens continued. "We look at a zone holistically and make sure all the monsters that appear in it can work together in interesting ways, and then we tweak the random possibilities to maximize those interesting ways without making it repetitive by actually placing them down in the same sequence every time."