Unity, available in free and pro versions, is one of the most popular third-party game engines available. It is a cross-platform game engine, making it easy to write your game once and then port it to PC, consoles, and even the web, making it a great choice for both indie and AAA developers. Building an FPS Game in Unity takes readers on an exploration of how to use Unity to create a 3D first person shooter (FPS) title, leveraging the powerful UFPS framework by VisionPunk and Prototype/ProBuilder 2.0 by ProCore3D. After some setting up, you will start by learning how to create custom weapons, prototype levels, create exterior and interior environments, and breathe life into our levels. We will then add polish to the levels. Finally, we will create a custom GUI and menus for our title to create a complete package.