The UnrealScript was the scripting language used by the engine UnrealEngine , and all games based on this engine, before being supplanted by the C ++, used today on Unreal Engine 4.

Originally created by Tim Sweeney  (in) , this scripting language is intended to enable the high-level manipulation of the concepts provided by the UnrealEngine engine with a simple and robust language.

The main source of inspiration in the creation of this language is Java and, like it, is compiled by bytecode . UnrealScript is approximately 20 times slower than C ++ , in favor of much lower CPU utilization .