Academic Game Engine (AGE) is developed in HCI laboratory. Its purpose is to aid in teaching of game development courses. The goal of the thesis is to extend the engine by a physics module, providing rigid body simulation. The student will study the theory of rigid body simulation and also solutions in available game engines, like Godot, Unreal Engine, and dedicated physics-based libraries, like Bullet physics. Based on the acquired knowledge a suitable implementation of rigid body simulation will be designed and implemented to AGE. More specifically, the student will implement simulation of motion of rigid bodies including reaction to collisions, external forces, and joints between rigid bodies. Rigid body "sleeping" technique must be provided as well. The implementation will further be evaluated on scenes of varying complexity. Collision detection algorithms are not subject of the thesis as they are already available in the engine.