Do you work primarily on the multiplayer or single-player environments, or do you just mix them up?

MZ: Personally, I'm primarily focused on Campaign, but during the main title release, I tend to pinch-hit occasionally in multiplayer, with just a quick collaboration and to check it out. Sometimes I'll hop over and finish out a space. The time I really focus on multiplayer is in downloadable content construction. On Halo 2 and 3, I actually got to make a map, which was really fun. I'd love to work on multiplayer full-time as well, but I can't do both necessarily.

Well, the scope at which a game like Halo is at, it's difficult to even own a large chunk of anything.

MZ: It is, and it's becoming more collaborative at every step.

So let's move on to the interplay between design and technology - they're each limited by each other in a lot of ways. How did you reconcile those? 

MZ: Absolutely. We're constantly evolving those targets and the development pipeline... evolving the art bar, is what I mean by "target", and that art bar is defined by budgets that we're engineering now. Especially with the 360 and the GPU and the CPU and the complexity of current-gen shader systems and physics and so many things going into the game. There's no simple answer.

When I started in the industry, it was pretty much, "What's my poly count? What's my texture budget?" Now, I can't even get a straight answer from the programmer, because there is no straight answer. They have the most elaborate profiling tools and are constantly tweaking performance based on, like, "Are you throwing a lot of grenades?" That's very different if you were driving six Warthogs, or if it's just you and a sniper rifle.

So do you sit down with the design team?

Brian Jarrard: It's like trying to wrap your head around this problem of... you have the engine. The engine can support either a lot of things like Warthogs or rocket launchers or something, and you have to design a map.

What kinds of things you put in the map are influenced by the design of the map, and vice versa. So if you're making a map for Warthogs, you'll have hills you can jump off of or whatever. But at the same time, the technological limitations might be based on how many Warthogs might be in the level. They're so interdependent that it might be difficult to find that spot.

Bungie/Microsoft's Halo 3

MZ: Absolutely. Again, we had the benefit of... in Halo 3, we had a pretty good idea of what our sandbox was. Certain things were more clear than others. The Warthog behavior was pretty similar, but the Scarab, for example, became a pretty different beast. In Halo 2, it was not really real. We faked it in a way that... in Halo 3, in the environment, it's AI-driven, it's stomping around, and if it stomps on a Warthog, that Warthog has physics and explodes.

And you can get on it and ride it while it's moving around. That's not something that you necessarily know what the target's going to be early on, so you prototype spaces and test that stuff early if you can. Some things come on late, but you can proceed with a lot more certainty with a space that's using Warthog combat that you've done for two games, whereas the Scarab is crazy and scary. And then you decide to throw two of them in the level and you're like, "Wow! Even crazier!"