The beta test will take place like this:

1) A registration website will be launched for people to go and apply. This will last for approximately 2 weeks (although it is subject to change)

2) After applications close, a representative cross-section of applicants will be selected - according to location, pc spec etc.

3) The selected applicants will be notified and will receive key discs - a personalised disc that will allow them to play the builds. They will also be informed of their "obligations" - to regularly play, to submit feedback etc. If people are not playing or not submitting feedback there is a possibility that their key disc will be deactivated remotely.

4) The selected applicants will then download regular multiplayer builds and will send in feedback. This may or may not be implemented according to whether it is a genuine bug or merely a question of gameplay taste / balancing.

5) There will be regular builds for people to download so there will be quite a few versions that they will have the opportunity to test.

Interestingly, there will also be an open beta trial LATER. At that point anyone can install a beta client and play S.T.A.L.K.E.R.. The only information still missing is the exact period for the closed beta test. The dates have yet to be confirmed.