Killzone 3 has gone gold, with the retail version due in just under a month. Plus, gamers who buy it on launch day will get another treat.

Those clever enough to pick up a specially marked copy of Killzone 3 will get access to the SOCOM 4 Multiplayer Beta.

“If you want to experience SOCOM 4’s 32-player multiplayer battles first, buying Killzone 3 is the easiest way to get access”, says Sony on its US PlayStation blog.

“To get early access to the beta, look for the SOCOM 4 callout on the front of all eligible copies of Killzone 3 (including both the standalone and Helghast Editions)".

“Inside the box you’ll find a PSN code that you’ll be able to redeem for your early access as soon as the beta goes live".

Killzone 3 is due out in February, while SOCOM 4 has yet to get an official launch date.