Throw something at the white-armored troopers, and they may toss a grenade back. Or they might just put their hands up. Or they could do something completely new, each time the game gets played.

Video games used to come preprogrammed with canned movements that expert players eventually could anticipate and figure out. But recent advancements in video game design -- and new game consoles with dazzling computing power -- have endowed computer-controlled characters with a sense of self-preservation and unpredictability not seen even a year ago.

The "Star Wars" game is just one of the games offering this advanced degree of realism. Game designers say this increasing sophistication is helping to put their medium on par with movies as a form of mainstream entertainment.

"I think you connect to these characters much more," said Torsten Reil, co-founder and chief executive of Britain's NaturalMotion Ltd., the company that developed technology used to breathe life into characters in the "Star Wars" game.

Called "euphoria," the technology generates animation on the fly, so each moment in a game is unique. The first game to feature it was Take-Two Interactive Software Inc.'s "Grand Theft Auto IV," whose April debut rivaled -- and in dollar terms bested -- blockbuster movie openings.

NaturalMotion's technology creates 3-D character animation in real time, simulating the way the body moves so it looks authentic.