# Game Physics Systems
Status: public
Confidence: medium (0.725) (verified)
Last verified: 2026-05-28
Generation: ai_assisted


## TL;DR

Game physics systems simulate collisions, rigid bodies, forces, and constraints so objects move and interact believably.

## Core Explanation

Physics middleware gives designers reusable behavior for motion and collision, but game teams still tune parameters, constraints, and collision modes for feel and performance.

## Source-Mapped Facts

- Unity built-in 3D physics is documented as an integration of the NVIDIA PhysX engine for object-oriented 3D projects. ([source](https://docs.unity3d.com/Manual/PhysicsOverview.html))
- Unity Rigidbody documentation says a Rigidbody lets the physics engine calculate movement from simulated forces, torque, collisions, and gravity. ([source](https://docs.unity3d.com/Manual/class-Rigidbody.html))
- Box2D documentation identifies Box2D as a 2D physics engine for games. ([source](https://box2d.org/documentation/))

## Further Reading

- [Unity Manual: Built-in 3D Physics](https://docs.unity3d.com/Manual/PhysicsOverview.html)
- [Unity Manual: Rigidbody Component Reference](https://docs.unity3d.com/Manual/class-Rigidbody.html)
- [Box2D Documentation](https://box2d.org/documentation/)