Hi, I hear a lot about game engines and using pre-made engines and making your own engines, but often used in different context. What exactly defines a game engine? I''ve written small breakout and space invaders type games... are these considered to contain a "game engine". Obviously I know games like UT or Q3 have very complicated game engines. My real question is... does every game have it''s own game engine, or could a game not have a game engine at all? Is a game engine something that makes the directx code invisible to the user of the engine? Any info or links about the subject would be appreciated. - Free Your Mind -

A propper game engine handles the following:

Rendering the graphics to the screen.
Physics, possibly kinematics, particle systems, and inverse kinematics.
Input.
and Sound.

Usualy the game engines come with their own level editors and animation utilities and converters.

With a game engine the only thing left for the programmers to write is the actual game code; such as AI, triggers, weapon fx, the menu systems, save games, load games and so on.