How to Run Faster in Fallout 3by Jared Newman ; Updated September 22, 2017
While roaming the nuclear wasteland of Fallout 3, players are likely to cover a lot of ground. The open terrain makes for fun exploration, but it can also be tedious. There is a legitimate way to run faster in all versions of the game and a command line cheat that PC users can use to greatly improve the main character's speed.
Holster your weapon by holding the "Reload" button. This is "X" on the Xbox 360 version, the Square button on the PlayStation 3 version and "R" on the PC.
Wear light armor, or just regular clothing, as opposed to heavier Power and Tesla armor.
Run as usual using the WASD keyboard keys on the PC game and the left thumbstick on the PlayStation 3 and Xbox 360 games. The main character should move noticeably faster.
With PC Console Commands
Open the command console by pressing the tilde (~) key during play.
Type "setgs fmoverunmult 8" (without quotes), then press Enter. Note that the number at the end may be changed to alter speed.
Press tilde again to close the command console.
Move as usual, and the player should be significantly faster.
Setting the run speed in the command console also changes the run speed for enemies, potentially making them difficult to kill. Reduce the speed for these confrontations.