The Gears of War 3 studio unveiled its new property at this year's Spike Video Game Awards, describing it as a building and survival title similar to Minecraft.
"We've had amazing success with games like Gears of War and Infinity Blade this year, but we decided it was time to switch things up a little bit and do something different and fun," said Epic's Cliff Bleszinski.
"Imagine a world where you explore, you scavenge, you build and ultimately you survive."
Fortnite will feature different mechanics depending on the in-game time of day. Players gather materials and build structures during the day to ward off the enemies that attack during the night. Resources can be shared with other members of the community.
The game switches to a third-person perspective at night when zombies attack, and takes on shooter mechanics.
Fortnite is yet to be assigned a release date, launch platforms or a publisher.
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