Serious Engine was developed by Croteam and incorporates the latest state of the art 3D technologies. Serious Engine is main power behind FPS games "Serious Sam: The First Encounter" and "Serious Sam: The Second Encounter" for PC and "Serious Sam" for Xbox, published by Gathering of Developers / Take 2 Interactive / Gotham Games.

The engine is suitable both for indoor and outdoor scenes and allows very complex architecture and scenery. It is also specifically optimized to allow large spaces and large numbers of entities in the game and on the screen at the same time. That enables an arcade action feel never before felt in  3D gaming.

The Engine is suitable for both first and third person games, and can be largely customized to suit specific needs of a game.

The Engine is designed to work on all of today's Win32 platforms:  Microsoft Windows 95/98/NT/2k/XP . That way, game development can be done on a professional operating system like Win2k or WinXP which is usually more comfortable for developers than using the average consumer operating systems.

The choice of APIs used was guided by the criterion of simplicity, stability and portability. In that spirit, both DX8 and OpenGL Are used for 3D rendering what enables high compatibility with all OpenGL and DX8 compliant 3D cards (every usable 3D accelerator nowadays).

TCP/IP is used in network system, allowing both LAN and Internet gaming.

Microsoft Visual C++ is used as a compiler of choice. Game content programming boils down to creating game DLLs which dynamically link to engine and editors, enabling direct interaction of the custom game code with editors and edited data right from the start. This is similar to plug-in system used in most of modern graphics applications, just that it is much easier to use.

Game content creation is done in two tools: Serious Editor and Serious Modeler. Serious Modeler is used to create game models from 3D files imported from standard 3D object editors (like Lightwave or 3D Studio). In Serious Editor, worlds are created and populated with entities. Both editors are designed to be highly efficient in terms of efforts and time needed to create any desired result, and to shorten the development cycle. The editors are made to satisfy the usual 'What You See Is What You Get' needs as much as possible. Also, every task was simplified as much as possible using existing paradigms like 'drag-and-drop', 'multiselection property editing', 'multi-document interface' etc.

Major improvements in usual 3D game editing that are unique to Serious Engine editors are embedded game testing and interactive CSG and lighting. Embedded game testing enables you to quick-test the game-play of your new level directly from any editing window in Serious Editor in a matter of seconds. Interactive CSG and lighting allows you to edit or move a light source in the editor, and the shadows it casts are updated as you move it. Also as you add new primitives to the world architecture, they can cast shadows immediately, so your level is always in the finished state. No need to compile it before running. That is possible because Serious Engine uses a completely new approach to CSG and lightmap calculation.

Entity code and AI is developed directly in the Microsoft Developer Studio integrated development environment. Same source code editor and debugger is used as if developing a usual C/C++ project. Language used is based on C++ and extended to provide syntax constructs for coping with common game programming issues. AI compiler, which is executed as a custom build rule, takes source code and generates C++ code which is in turn compiled by the built-in VisualC++ compiler. Generated executable code can therefore be optimized for performance or debugged with the built-in VisualStudio debugger.