The MDA framework is a critical attempt to formalise game design. It takes the three main components of what makes a game – rules, system and ‘fun’ – and translates them into design terms – mechanics, dynamics and aesthetics.
Mechanics are the core workings to the game as described in code, or in objects such as dice or spinners in a board game.
Dynamics are the way the mechanics interact with player input as the game progresses, the connection between the player and the game world.
Aesthetics are the emotional responses desired (and to a certain extent, expected) from the player whilst engaged with the game.
The core idea of MDA is that the designer experiences things mechanics end first, whereas the player’s view is the opposite – aesthetics first, then dynamics, then mechanics. Each of these categories is not static; it flows and effects the next, so designers have to be aware of how minor mechanic adjustment may affect play aesthetics.
Aesthetics fall into these (see image) broad categories, and while most games will engage a selection of these there is usually one core aesthetic.
REF: Hunicke, R., LeBlanc, M., & Zubek, R. (n.d.). MDA: A formal approach to game design and research[online article]. Retrieved from http://www.cs.northwestern.edu/~hunicke/MDA.pdf