This is the Decision-Action-Response (DAR) Theory.
Element: An Element is a discreet DAR section of a game that involves a significant decision by the player and/or provides a significant, specific response by the game, whether positive or negative.
Game elements are hierarchical; an entire game is an element composed of many sub-elements, each of which can have sub-elements. This hierarchy continues until the loss of significance of the three parts of DAR. Analysing an insignificant DAR element into a game is pointless.
NotesAfter spending some more time thinking about my initially proposed DAR theory (Decision-Action-Reward), I decided to make some small modifications to it.
The principle change is that we define DAR as Decision-Action-Response, thus preserving the term "Reward" for positive responses, and semantically allowing for negative or neutral responses to decisions and actions.