Gears of War: E-Day campaign length and acts

How many acts are in the campaign?

The official Xbox achievement list names story achievements in Acts 1, 2, 3, 4 and 5, and completion achievements refer to finishing all acts. That supports a five-act answer. Chapter lists on guide sites differ in how they count the prologue and epilogue; this page does not present a numbered chapter total until it can be matched against the launch game's chapter-select screen.

How long does a playthrough take?

There is no single official campaign duration. A GamesRadar reviewer reported 16 hours for a run that included most side objectives. Treat that as one documented playthrough, not an average or a time guarantee. Higher difficulty, exploration, collectible hunting and co-op pacing can change the result.

What makes completion longer than the story?

Xbox lists distinct achievements for all secondary objectives, all Hard Cases, all collectibles, co-op completion and Insane difficulty. A story finish does not automatically meet those goals. Use the completion checklist to decide whether you need a story run or a full campaign cleanup.