The Call of Duty: Black Ops III multiplayer beta will be available exclusively on PS4 for five days, from the 19th of August to the 23rd of August, Activision revealed. However, Treyarch and Activision haven't announced an end date to the beta, so we don't know how many days players on other platforms will have to play and enjoy the beta.
In order to get access to the multiplayer beta, all that players have to do is pre-order Call of Duty: Black Ops III on PC, PS4 and Xbox One. Unfortunatelly, Activision still hasn't revealed anything for PS3 or Xbox 360, which most likely means that the beta won't launch on either console.
Call of Duty: Blacks Ops III releases worldwide on the 6th of November on PS4, PS3, Xbox One, Xbox 360 and PC.