Zero War is a Marvel Fortnite Loading Screen from the Iron Man Zero set. Zero War was first added to the game in Fortnite Chapter 3 Season 4.What is Fortnite ?Fortnite is a survival game where 100 players fight against each other in player versus player combat to be the last one standing. It is a fast-paced, action-packed game, not unlike The Hunger Games, where strategic thinking is a must in order to survive.