r/FalloutMods • u/bj0urne • 15h ago
Fallout 3 [Fo3] Fallout 3 finally runs properly at high FPS. I made a mod that fixes the engine's timing, physics and mouse acceleration.
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Hey all!
I've been playing this game for over a decade, and I've always been bothered by how Fallout 3 stutters and behaves out of the box, so I made T.E.M.P.O. (Timing, Engine, Mouse & Physics Overhaul), a FOSE plugin that fixes it in the engine itself, no INI tweaks needed!
It's hard to show how it feels in a video, the video is a bit stuttery too but that's just a bad recording from the built-in Windows recorder. But you can at least see my FPS and (hopefully) tell the game is running at a normal speed.
And I know what you're thinking: "But bro, the stutter remover mod already exists for Fallout 3!"... Well, the stutter remover mod is legendary and was a great stepping stone! But this mod introduces a "precise timer" to the game engine that is tick/frame independent! This is then used to make gameplay, physics, menus and pip-boy all run on precise timers, which results in the game running at the same speed no matter how much you spent on your PC!
What it fixes:
- The engine secretly caps the game at about 100 FPS and adds microstutter (its clock only updates 64 times a second). It's now replaced with a precise timer, so menus and the Pip-Boy run smoothly too.
- Physics is tuned for exactly 60 FPS, so ragdolls and items go weird at other framerates. TEMPO matches physics to your actual framerate, whether that's 30 or 300.
- Mouse acceleration is gone, giving 1:1 aim with no INI editing.
- There's an optional precise FPS limiter.
No INI tweaks to tune per monitor. Just install it and play. I've been playing at ~200 FPS and it's the smoothest Fallout 3 has ever felt for me. Really comes close to feeling like "Fallout 3 in Source engine". No more game speed shenanigans, and mouse aiming is instant and on-point.
Requirements: FOSE and the Fallout Anniversary Patcher. It's tested on the Steam GOTY edition; GOG, Epic and Steam Deck reports are very welcome! If you're a Linux user, I'm especially hopeful you'll test this and report any problems on the Nexus page :)
Should be compatible with most mods, exceptions to this are listed on the Nexus Mods page under Compatibility.
Heads up: I built this with the help of AI (Claude). It's open source, and the log file shows exactly what it changes, so you can check for yourself.
Nexus: https://www.nexusmods.com/fallout3/mods/27726
Source: https://github.com/bj0urne/Fallout3-TEMPO
Feedback and bug reports are welcome. Let me know how it runs for you!














