GAME THEORY; For Game Maker, There's Gold in the Code

COMPUTER games, like cars, are praised for their exterior styling: the landscapes; the lighting; the number, size and relative intelligence of the monsters. Less attention is paid to what's under the hood. But that is where the real technological advancements are made.

In the case of Unreal, the hit first-person shooter of 1998, the game's engine -- the underlying software -- has become a cottage industry. The game took three years and $3 million to make, and the vast majority of that time and expense went into the engine. The programmers created the whole tool set from scratch. It was the software equivalent of designing your own hammers, ladders, power saws and paintbrushes before you begin construction on a house.

Unreal was a spectacular gamble for its developer, Epic Games, and a nail-biting investment for its publisher, GT Interactive, but it paid off. Unreal was the most gorgeous game anyone had ever seen. It sold more than a million copies and made $10 million for Epic -- not bad for a company with 13 employees.

All of a sudden, those custom power saws and paintbrushes started looking really attractive to other game developers, and Epic was in the tool business. To date, 16 projects include a licensed version of the Unreal engine, for which Epic charges $250,000 to $350,000 up front and gets royalties of 5 percent to 7 percent.

These projects run the gamut, from the swaggering Duke Nukem Forever to The Wheel of Time, a fantasy adventure based on Robert Jordan's novels, and TNN Outdoor Pro Hunter, which combines bucolic scenery with Doom-style game play. The Unreal engine purrs beneath the dark and sophisticated Deus Ex, the forthcoming title from Ion Storm, as well as the candy-colored corridors of Nerf Arena Blast, published by Hasbro Interactive's Atari label.

''There are games that look and feel a bit too much like Unreal,'' said Mark Rein, Epic's vice president and engine evangelist. ''And there are some that you can't even recognize. Our engine is really just the paints, and anybody can go out and buy a set of paints. What's more important is the painter.''

Of course, Epic has been painting on its own canvas as well -- Unreal Tournament promises to be a hot seller for the holidays. But the company has also employed programmers to work full time on the engine. In an industry where costs continue to spiral upward, reusable code is the holy grail. The reason Unreal can license its engine in the first place is that few people can afford to write their own anymore, with the notable exception of Id Software, which developed Doom and Quake and licenses the Quake 3 Arena engine for a half-million dollars.

''As technology marches on, it gets harder and harder and more and more expensive to write an engine from scratch,'' Mr. Rein said. ''Even at Epic, our next-generation engine, which we're starting on now, will use existing technology. Sure, the things that become obsolete, like the rendering code, will be thrown out and completely rewritten. But the infrastructure and the architecture will move forward from the Unreal engine because it was designed for that in the first place. There's no question, it's a huge leg up.

''People who create awesome content can save themselves a couple years and a lot of money, especially as we get more and more multiplatform-oriented. Right now the Unreal engine runs on Windows. It runs on Unix. It runs on Linux and Mac, and we're looking at getting it going on certain console systems. You want to put out a Mac version of your game, you've got compatible code already done. You want to do Linux, it's the exact same source code.''

As stakes rise in the game industry, developers have to spread their costs and risks across multiple platforms. Licensed engines are a shortcut and a hedge. As 3-D engines themselves become increasingly expensive to design, a few underlying technologies gain critical mass. (In that respect, first-person game engines increasingly resemble their steel-and-piston counterparts.)

But even as uber-engines coalesce in the game industry, they are starting to compete in other arenas.

In the case of Unreal, that means real estate. There is a company on Long Island, Perilith Industrielle, whose sole business is building architectural fly-throughs for business clients using a customized version of the Unreal engine, a k a Unrealty (www.unrealty.net). Unrealty allows architects and developers to model an existing building or a concept in 3-D, explore it in real time and interact with multiple users on a network.

If far-flung financiers want to inspect the layout and disagree about the size of the windows or the carpet colors, they can save themselves some air fare. Perilith has also engineered a virtual tour guide to usher visitors through the property.

So far, Unrealty has been used to model the Heartland Business Center, an office complex in Deer Park, N.Y., and a virtual bank in Germany, as well as the Long Island Technology Center developed by Rudin Management, the property developer responsible for Manhattan's first wired-to-the-gills dot-compound, 55 Broad Street. Budding start-ups will be happy to know that their future office space has so much in common with Klingon Honor Guard.

Aside from combat and real estate, the engine has applications of genuine cultural value. Witness the Virtual Notre-Dame project, a fly-through model of the famed cathedral (www.vrndproject.com).

For Gothic architecture in cyberspace, it doesn't get any better than this. You can soar up to the ceiling and look down from the arches, basking in multicolored sunlight that streams from 40-foot stained glass windows. You can see other visitors flying, like yourself, as small transparent orbs of pulsing light. (An elegant metaphor for the human soul, the glowing lights make online avatars seem like crude paper dolls.)

The virtual cathedral is 9.4 megabytes. But even on a 56K dial-up modem, it's worth the wait. As you survey the structure, you have to give credit to the game engine that holds it up, just as you acknowledge a socialite who started her life as a showgirl: In prestigious company, she can hold her own. She cleans up really well.