ALAMEDA, Calif. -- The best-selling game, where players must manipulate geometric shapes that fall rapidly down the screen, is also one of the best-known Soviet imports to the United States, and its publisher thinks the time is ripe for a new version.
But the two principal programmers responsible for the game have decided the best way to cater to the U.S. market is to understand it firsthand. So Alexey Pajitnov and Vladimir Pokhilko, his partner, have moved with their families to the San Francisco Bay Area for an extended stay, perhaps as long as three years.
Many of the programmers who are working on projects directed by Mr. Pajitnov and Mr. Pokhilko are still in Moscow. They get their instructions from the pair, who are working with their U.S. publisher, Spectrum Holobyte.
The problem now is deciding just what to tell the programmers back home to do.
"It's very hard to improve Tetris, but it's very easy to spoil the game," Mr. Pokhilko says, noting that ideas for changing it are considered and discarded every day. It's easier for the men to say what they won't change.
"We've definitely decided not to add some new kinds of figures. There should be seven figures and no strange new ones," Mr. Pajitnov says.
"And we've definitely decided to leave the principle of the deleting of lines, and against deleting other [areas] like squares or areas of one color."
One thing that will probably be added is some kind of "trace" or replay feature so players can review their moves and mistakes.
Mr. Pajitnov says coming to the United States was a key part of improving Tetris -- and developing other software. One reason is that the two are closer to their business partners, allowing them to iron out deals more easily.
Another is the comfort of U.S. copyright laws, which afford them protection for their work that is effectively absent in the Soviet Union. While there are Tetris arcade machines in their country, for example, neither man earns one kopeck in royalties.
And software copying of anything, especially U.S.-made software, is widespread there.
"Symantec was going to sell Norton Commander in the Soviet Union, but we told them not to bother," Mr. Pokhilko says. "Everybody already has it."
But the principal reason for their move is to become familiar with the subtleties of American culture they feel they must incorporate into their games.
While Soviets know about a few major American cultural icons such as Mickey Mouse, Mr. Pajitnov says, "People don't know about the Simpsons, about Ninja Turtles. There is no 'Star Trek' and no comics. Our imagination about you is very limited."
The two are hard at work on their favorite project at the moment, one that's not a game but what Mr. Pajitnov describes as "human software." It's a program called "Elfish," short for Electronic Fish.
Elfish is a computerized aquarium, but one unlike any sort of desktop fish tank on the market. It is not meant as a screen-saver or conversation piece, Mr. Pajitnov says, but as a "tool for creativity" where users can spend hours designing their individual tank, from "growing" beds of seaweed (some generated with "fractal" mathematics), to scattering rocks about the bottom, to stocking it with their choice of tropical fish.
The result is a realistic-looking aquarium where the fish seem to swim naturally in all directions.
If you don't want to pick your fish directly from the supplied database of sea creatures, you can call up a map of the world's oceans and go fishing anywhere you want. What you catch, you can put in the tank -- including sharks.
The fish are also unique. Each has its "genetic code" that the program interprets to generate the physical appearance and characteristic movement of the fish. To boot, you can breed the fish, and just as in nature, breeding two particular fish together doesn't give you identical offspring each time. Color, shape and size vary, although all the characteristics come from the parent fish.
Just to make things more lively in the tank, breeders can irradiate their fish eggs to create "mutant" fish that can be bred later.
"We call them Chernobyl fish," Mr. Pokhilko says with a smile.
Elfish has been almost two years in the making, with 15 programmers toiling on it in Moscow. And the working version is massive. It needs a 386-based, IBM PC-compatible computer and the little-used OS/2 operating system, and requires 8 megabytes of RAM and a Super VGA screen -- as rare a breed of computer as some of the pair's Chernobyl fish.
The principal remaining task for the programmers is to shrink Elfish so it will work on a more ubiquitous machine.
It's clear the pair understands the basics of capitalism. Mr. Pajitnov envisions a brisk trade among fish "breeders" to sell their creations for other users to put in their tanks.
Mr. Pajitnov says such opportunities to make money are beginning to attract Soviet programmers to the United States, even though it can take months for them to adjust to life here.