ABSTRACT
Most game engines provide a suite of runtime soft ware components that together provide a framework upon which a game’s unique rules, objectives, and dynamic world elements can be constructed. There is no standard name for these components within the game industry, but we will refer to them collectively as the engine’s gameplay foundation system . If a line can reasonably be drawn between the game engine and the game itself, then these systems lie just beneath this line. In theory, one can construct gameplay foundation systems that are for the most part game-agnostic. However, in practice, these systems almost always contain genre-or game-specifi c details. In fact, the line between the engine and the game can probably be best visualized as one big blur-a gradient that arcs across these components as it links the engine to the game. In some game engines, one might even go so far as to consider the gameplay foundation systems as lying entirely above the engine-game line. The diff erences between game engines are most acute when it comes to the design and implementation of their gameplay components. That said, there are a surprising number of common patt erns across engines, and those commonalities will be the topic of our discussions here.
