Inertia - Physics Motion Response System - F4SE (Updated)

This mod adds weight-based movement inertia and realistic cornering deceleration to Fallout 4, making heavy equipment feel more stable, acceleration smoother, reverse stronger, and combat more immersive.

Original address:

Prefix:

Fallout 4 Script Extender (F4SE)：

Mod Configuration Menu：

Mod Configuration Menu - RD (optional):

Runtime Database：

Updated on September 12th:

Version 2.3.0

Overview

->Increase NG compatibility

->This mod now requires a runtime database

->Added MCM

Updated on July 29th:

Version 2.2.0

Bug fixes

-> Fixed an important game hook

Updated on June 28th:

Version 2.1.1

• Adapted to the latest game version

The OG version (applicable to version 163) and AE version (applicable to anniversary upgrade version) files have been uploaded. Choose one of the two to install according to your own game version.

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Introduction

In the original Fallout 4, player movement felt very responsive and game-like, but lacked a sense of physical weight and momentum. Characters can accelerate, stop, and reverse in an instant without ever feeling grounded.

This creates a subtle break in immersion. Carrying heavy gear should affect how you move, how quickly you change direction, and how stable you are during tight turns.

This module directly introduces weight-based motion inertia at the engine level. Acceleration and deceleration are adjusted smoothly, and the load-to-weight ratio dynamically affects the response.

Even

Heavier gear will slow down acceleration, create more resistance in reverse, and make momentum more noticeable. Sharp turns can cause real deceleration, especially when carrying a heavy load.

Inspired by modern tactical shooters known for grounded controls and weight simulations, the system brings a more realistic sense of movement to Federation without sacrificing responsiveness.

The goal is not to make movement clunky or artificially difficult, but to restore logical physical behavior and believable player momentum while keeping controls smooth and responsive.

Configuration

The mod is fully configurable via the INI file included in the F4SE plugin folder.

All game parameters such as acceleration, deceleration, weight effects, reversing behavior and cornering deceleration can be adjusted to match your preferred movement style.

in the INI file

Each setting is clearly described so you can fine-tune the balance between responsiveness and realism. Whether you prefer delicate momentum or a heavier, more tactical feel, the system can be customized to fit your play style.

Custom INI override

The mod supports a flexible INI override system, allowing additional configuration files to modify the main settings without modifying the base Inertia.ini.

Overlay files can be placed in the Data\F4SE\Plugins\InertiaCustomINI folder. The mod will automatically load every .ini file found in this directory and apply their settings on the main configuration.

Files are processed in alphabetical order, meaning that subsequent files can overwrite values ​​from previous files. This allows mod lists or patches to adjust specific parameters without leaving the original configuration unchanged.

start up

, the mod will write detailed information to the log file, including which override files were detected and which settings were overridden. This makes it easy to verify that custom configurations are applied correctly.

Multiple overlay files can be used simultaneously, making it easy to separate different tweaks, patches or balance changes into separate configuration files.

Compatibility and additional information

Debugging only works with WASD keys.

Install

Install the mod using your favorite mod manag …