http://www.pcgamer.com/fortnites-controversial-battle-royale-mode-is-now-live/

Fortnite Battle Royale, the 100-player last-man-standing mode that caused such consternation and heartache at PUBG studio Bluehole, is now live and free for everyone. The 1.6.3 update released today also brings Duos and Squad match types that enable players to square off in pairs or groups of up to four, three new weapons, and an array of tweaks and bug fixes. 

Four-player Squad matches are live now, while the two-player Duos will be activated once there are enough players to support matchmaking in both modes, Epic said. Teams can be filled by inviting people on your Friends List, or through the "Fill" option, which will automatically top it up. Other relevant points: