E3: 3D Realms plans Steam-style online distribution for Prey

US game developer 3D Realms is set to follow in the footsteps of Half-Life creator Valve and offer its forthcoming PC first person shooter Prey over an online distribution system from day one.

The game, which is being showcased at E3 on the ATI stand and is heavily promoted around the show, will be available online over the Game xStream system, which is not dissimilar to Valve's own Steam system.

3D Realms plans to allow users to download the full game ahead of its launch day, and then unlock the content at the moment of launch - but taking the technology a step beyond Steam, Game xStream will also allow players to purchase the game after launch and begin playing within minutes, as it intelligently streams content across the network while the game is being played.

"Gamers will be able to pre-order and pre-load Prey onto their hard drives, ready for instant activation and play upon the official release date," explained 3D Realms' CEO Scott Miller.

"Or, after the official release, players will be able to buy the game and begin playing in minutes, as if the full game was already downloaded. This is what sets Game xStream apart from anything else the industry has seen."

The firm's partnership with Game xStream isn't just for Prey, though - it's described as the beginning of a long-term partnership with the company which will also extend to future games, which implies that the long-delayed Duke Nukem Forever may also be distributed on the service when it finally appears.