The early sales were no real surprise. Retail embargo dates for video games get broken about as often as eggs at an all-you-can-eat omelet festival.

But here's the twist. Given the game's prior problems with piracy, developer Valve built a verification system into "Half-Life 2," requiring buyers to authenticate the game online before they could play it. Anyone attempting to do so this weekend, however, was out of luck.

Vivendi Universal Games, which holds the publishing rights to "Half-Life 2," refused to allow the developer to activate purchased games, Valve charged in a news release.

"Vivendi is insisting that the game has not yet been released, and has threatened that Valve would be in violation of its contract if we activate the Half-Life 2 ... authentication servers at this time," said Valve spokesman Doug Lombardi.