Armada

Armada is a science fiction novel by Ernest Cline, published on 14 July 2015 by the Crown Publishing Group, a division of Penguin Random House. The story follows a teenager who plays an online video game about defending against an alien invasion and then discovers that the game is a simulator intended to prepare him and players around the world for an actual invasion. The game the players are good at turns out to have been a selection process rather than a pastime.

The premise depends on the overlap between a hobby and a real event. Zack is a high school student who has spent his life on the fiction he loves, and the appearance of a ship that matches his game makes the boundary between the two the novel's problem rather than its joke.

Wil Wheaton, who had narrated the audiobook of Cline's previous novel, Ready Player One, narrates this one as well. The book received mixed to negative reviews, but it was a New York Times bestseller. The world of the novel has been prepared for the invasion without knowing it, which is why the players' skill is treated as a resource rather than a hobby.