Fallout New Vegas Mouse Acceleration Guide and How to Disable It

Playing Fallout New Vegas on modern PC setups often highlights the age of its underlying Gamebryo engine. One of the most noticeable issues players encounter immediately upon starting a new game is erratic camera movement caused by built-in mouse acceleration. Removing this unwanted feature is essential for achieving smooth, predictable aiming across the Mojave Wasteland.

Understanding Mouse Acceleration in Fallout New Vegas

Mouse acceleration dynamically adjusts your cursor sensitivity based on how quickly you physically move your mouse. While this feature was originally designed to aid desktop navigation, it heavily disrupts muscle memory in first-person shooting games. When active, moving your mouse across the same physical distance at different speeds results in drastically different camera rotations.

In Fallout New Vegas, this setting is enabled by default deep within the game configuration files. The resulting movement feels floaty, inconsistent, and unresponsive during intense combat scenarios. Disabling it restores a true 1:1 ratio between your hand movements and your in-game crosshair.

Modifying the Game Initialization Files

To turn off mouse acceleration completely, you must edit the game configuration files stored in your installation directory and documents folder. Navigate to your Fallout New Vegas main directory and open the file named Fallout_default.ini using any standard text editor. Locate the Controls section within the document to begin tweaking the input variables.

Under this section, you need to add specific lines of text that force the engine to ignore acceleration curves. Adding parameters such as fForegroundMouseAccelBase=0 and fForegroundMouseAccelTop=0 directly disables the scaling algorithms. Be sure to save the file after making these modifications to ensure your updates take effect.

Updating Additional Configuration Files

Modifying the default file alone is often not enough because the game reads settings from your user profile directory. You should navigate to your Documents folder, locate My Games, and find the FalloutNV folder containing Fallout.ini and FalloutPrefs.ini. Open both files and insert the exact same controls parameters to maintain system-wide consistency.

If you use a mod manager or custom script extender, these tools might create isolated configuration files for separate player profiles. Check your manager settings to verify that your modified INI files are not being overwritten when launching the game. Taking this extra step guarantees that mouse acceleration remains disabled during every play session.

Optimizing Additional Mouse Settings

Beyond disabling acceleration, tweaking horizontal and vertical sensitivity helps establish a comfortable control scheme. By default, vertical aiming sensitivity in Fallout New Vegas is significantly slower than horizontal sensitivity, creating an uneven feel. Adding matching scale values to your configuration files balances axis movement for uniform control.

You should also check your operating system settings to ensure Windows pointer precision options do not interfere with raw input. Disabling pointer enhancement in your system control panel provides cleaner raw data directly to the game client. Combining these adjustments creates a modern, responsive aiming experience across the entire wasteland.