The multiplayer survival game uses building as its core, as players have to work together to scavenge gear and building materials, create fortified structures and then defend their base from waves of monsters.
Players will have deep control over the structures they build, placing fences, stairs and multiple levels. The example was given of placing holes in a fort's roof tiles to use as a lookout and for sniping enemies.
It is being developed exclusively for PCs at this time, and will be the first title from Epic Games to use the studio's Unreal Engine 4.
Fortnite will also be supported after its release with updates similar to titles like Minecraft and Team Fortress 2. When asked during the panel if players could create Rube Goldberg-like traps in their forts design, director Cliff Bleszinski said the feature wouldn't be available at launch but is "kind of a no-brainer" to add in future updates.
No release date was given during the panel, although Epic Games has previously said that its first Unreal Engine 4 game would not release until 2013.
Screenshot gallery - first images of Fortnite below:
Copyright: Epic Games