Havok Physics

Havok Physics is a physics engine used in Fallout 3 and Fallout: New Vegas.

Gameplay
It is designed for computer and video games by allowing interaction between objects or other characters in real-time and by giving objects physics-based qualities in three dimensions. By using dynamical simulation, Havok allows for more lifelike worlds and animation, such as ragdoll physics or intelligence in massive falling objects. The company has also released a Havok Animation. Havok was purchased by Intel in 2007. On October 2, 2015, Microsoft announced it had acquired Havok.

During the development of Fallout: New Vegas, Obsidian Entertainment had to upgrade from an older version of Havok physics to meet compliance, which Joshua Sawyer stated was one of the biggest technical issues during development, as it was a very disruptive and resource-intensive process.