Konami has said the European Metal Gear Online beta will run from 21st April to 6th May.
The client will be available to download from 17th April, as Sony told us earlier.
Two of the five maps from the full game will be available to mess around on: Blood Bath and Groznyi Grad.
The former is two-tiered scenario, while the latter is that big (and fantastically named) Shagohod complex from MGS3 that has human catapults to throw you around.
The other three joining these at launch are Ambush Alley with its trenches and sandbags; Midtown Maelstrom with its Middle Eastern alleyways; and Urban Ultimatum with its rooftops.
Metal Gear Online will be released alongside Metal Gear Solid 4: Guns of the Patriots on 12th June around the world.
It lets 16 of you fire bullets at each other online, in the hope that one will penetrate and cause massive internal bleeding and lead to death. And then respawn.
There are Deathmatch, Team Deathmatch, Capture Base and Sneaking missions. It's plenty of fun, too, as you can find out in our first impressions of Metal Gear Online.