TR: Does how you build the creature affect anything in the game beyond how the creature behaves?

LB: One of our original visions . . . was to do procedural music, [which we achieved with help from electronic musician Brian Eno]. So, as you create your creature in the editor, if you're putting on a more aggressive part, the music starts to turn a little more ominous. If you're putting on a more socializing part, it turns a little more perky and happy. And that happens throughout the game, in fact.

TR: One goal of the Creature Creator was to make it relatively easy to use, while also giving people a lot of range in what they could create. How did you pull that off?

LB: The Creature Creator's interface is probably the single item that we spent the most time on. To make it something that feels as simple as shaping clay, allowing players to easily add parts, stretch them, or rescale them, we taught the computer to respond to what the player was doing. If the creature is facing the player, it will manipulate the limbs differently than if the creature is to the side. We created methodology like symmetry, so that if you're dragging on a leg and you put it to the side of the creature, it's going to have two of them.

TR: Because so much of the behavior of these creatures is procedurally generated once the game is running, my understanding is that the files for the creatures themselves turn out to be much smaller than for a 3-D model, for example.

LB: What you're doing with your Creature Creator is creating a recipe for a creature. Because the computer builds the creatures up procedurally, the file that stores [the creatures] gets reduced down to about 8 K. We're talking about kilobytes, not megabytes or gigabytes [as you might expect for most 3-D models].

TR: Since the file sizes are so small, are you making mobile versions of Spore as well?

LB: We have a version of Spore called The Beginning that will be available on the mobile phone, but, in the full game, the underlying technology to do procedural animation and some of the AI that we're doing definitively takes advantage of the PC platform's computing capability. While procedural generation gives you a tremendous amount of creativity, and it gives you this ability to reduce files down to a very small size, the way that we're putting procedural generation into action for the full game is using quite a bit of computing power.

TR: What kind of computing capability will a player need to be able to run Spore?

LB: We are actually running on a system spec for computers that shipped about three years ago, and we'll also launch [the full version] simultaneously on the Mac and the PC.