Epic has announced its third annual Epic MegaJam to kickoff on November 2nd at 2pm ET, when the theme will be announced over livestream through Twitch, Facebook, and YouTube.
The event lasts seven days with submissions due on November 9th and accepts teams anywhere from a single developer to 5 developers. Prize details are coming soon, but current sponsors include Intel, Falcon Northwest, Allegorithmic, SpeedTree, and SideFX. You can view games that have been created in the past at the Hall of Fame on the UE forums.
Learn more from the event announcement at https://forums.unrealengine.com/unreal-engine/events/1363542.