For those lucky gamers who managed to nab themselves a Halo 3 beta key over the last couple of months, the wait is almost over to test-drive the new first-person shooter. The multiplayer beta will be going live on May 16 on Xbox Live globally, Microsoft announced today.

　　The announcement also scotched rumours that there would be two different beta start dates for those who had got their beta keys either through the Rule of Three promotion or through purchasing a specially marked copy of Crackdown. Access to the beta will be rolled out simultaneously worldwide at 1 p.m. GMT (5 a.m. PDT) on May 16, and will end on June 7 at 7:59 a.m. GMT (June 6 at 11:59 p.m. PDT). Those who have not yet obtained a Halo 3 beta key can still sign up by buying a copy of the Xbox 360 game Crackdown.

　　There will be three maps available to play--Snowbound, High Ground, and Valhalla--which will "represent a mixture of large- and medium-scale combat environments." New vehicles will include the nimble Mongoose all-terrain vehicle, and new weapons will be available, such as the "new and improved" Assault Rifle, the Brute Spiker, the Spartan Laser, and Spike Grenades.

　　On Bungie.net, community liaison Frank O'Connor makes the disclaimer that the Halo 3 multiplayer beta isn't completely indicative of the final product that is releasing this fall. O'Connor says there may be some "quirks, a couple roughedges and all that jazz," and that testers' focus should be on gameplay rather than snazzy graphics.

　　Even though the beta will include the aforementioned new vehicles and weapons, Bungie isn't pulling out all its tricks until the fall. "...a lot of secret features are hidden in this Beta," says O'Connor. "We're keeping a lot of our powder dry for fall."

　　But for those who can't wait for May 16 to see the game in action, Bungie has released a "Vidoc" titled "Is Quisnam Protero Damno" that shows off the multilpayer portion of Halo 3 in action. The video is now available at Bungie.net, Xbox Live Marketplace, and GameSpot.

　　In the short, several new features of the game are shown off, including the Spartan-launching man cannon (and the inevitable sniper picking helpless players out of the air), the shield grenade first shown off in the Halo 3 TV ad, and instant replay, complete with customizable camera angles and freeze-framing for recounting pure ownage.

　　O'Connor also says that the mysterious function of the X-button is also revealed in the video, but doesn't explain exactly what it does in the announcement on Bungie.net. However, on the Bungie.net forums, he says "X Button is DEPLOY EQUIPMENT" (emphasis in original) and that it is shown three times in the video. Halo fans are assuming that the Shield Grenades and Trip Mines (explained in the video) are two of the instances, and the third may be a portable gravity lift (watch the blue Spartan on the left side of the screen 23 seconds into the video) which allows players to boost up to higher ground with ease.

　　For more information on Halo 3, read GameSpot's previous coverage.