Anyone can download the engine and use it for everything from game development, education, architecture, and visualization to VR, film and animation. When shipping a game or application, developers pay a 5% royalty on gross revenue after the first $3,000 per product, per quarter. Epic succeeds only when creators succeed.
This is the complete technology Epic uses to build their own games. Unreal Engine 4 scales from indie projects to high-end blockbusters; it supports major platforms; and, it includes 100% of the C++ source code. Epic’s goal is to give developers everything, so they can do anything and be in control of their own schedule and their own destiny. Whatever is required to build and ship a game can be found in UE4, sourced in the Marketplace, or built and shared it with others.