The Blender Game Engine was a free and open-source 3D production suite used for making real-time interactive content.

The game engine was written from scratch in C++ as a mostly independent component, and includes support for features such as Python scripting and OpenAL 3D sound.

Key code in the physics library (SUMO) did not become open-source when the rest of Blender did, which prevented the game engine from functioning until version 2.37a.

Version 2.42 showed several significant new features, including integration of the Bullet rigid-body dynamics library.

During the 2010 Google Summer of Code, the open-source navigation mesh construction and pathfinding libraries Recast and Detour were integrated; the work was merged to trunk in 2011.