There are a total of four chapters and a prologue in Fort Solis, which mark different points of the night as tension and events escalate through the story.
Each chapter varies in length, and how long they take to complete will depend on how much you explore, since objectives are rather easy to complete.
They chapters are:
The chapters all vary in length, and how long they take to complete will depend on how much you explore.
During my playthrough, the prologue took me just over 15 minutes to complete, while the first full chapter took me just over an hour due to the high levels of exploration.
I finished the second chapter within around 40 minutes, while the third was finished in just over half an hour.
The final chapter took me around 30 minutes to complete, combining for a total playtime of around three and a half hours for the game’s main story.
Although I explored a lot throughout those chapters, I found that I was still missing a good chunk of collectables, so I spent another hour or two fully exploring the mining facility to grab the remaining flags, posters, messages, research notes, audio notes, and videos.
Any achievement or trophy chasers will be glad to hear that there’s free roam after completing all chapters, giving you a chance to find any missing collectables and trophies.

Selecting the ‘Continue’ option from the start menu after finishing the game sends you back to a late section of Chapter Four, with all five keycard levels on you.
That’s it! Now you know how many chapters are in Fort Solis. Make sure to check our other guides on the game as well as our review if you’re thinking of grabbing the game!
Recommended guides:
How to solve the server room puzzle in Fort Solis
Where to find all keycards in Fort Solis
Fabio Crispim
A writer and cat lover who started gaming in the late 1990s and hasn't stopped gaming since. In the meantime, contributing to online publications like Attitude Magazine, WeekendNotes, and more. His favourite games include Elden Ring, The Last Of Us Parts 1 and 2, Red Dead Redemption 2, and Resident Evil 4.
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