Interactivity is closely linked to the concepts of design, systems, and meaningful play. When a player interacts with the designed system of a game, meaningful play emerges.
There are many valid definitions of interactivity. Cutting across all of them are four modes of interactivity: Mode 1: Cognitive interactivity; or interpretive participation; Mode 2: Functional interactivity; or utilitarian participation; Mode 3: Explicit interactivity; or participation with designed choices and procedures; Mode 4: Beyond-the-object-interactivity or cultural participation.
These four modes are not distinct categories but are instead overlapping ways of understanding any moment of interactivity. They usually occur simultaneously in any experience of a designed system.
Not all interaction is designed interaction. When an interaction is designed, it has an internal structure and a context that assign meaning to the actions taken.
An interactive context presents participants with choices. Choices can be micro-choices of moment-to-moment interactivity or macro-choices, which concern the long-term progress of the game experience.
The basic unit out of which interactive meaning is made is the action > outcome unit. These units are the molecules out of which interactive designers (including game designers) create larger structures of designed interaction.
Within each action > outcome event is a series of five stages that help construct a choice in a game. These stages are expressed through the following questions:
What happened before the player was given the choice?
How is the possibility of choice conveyed to the player?
How did the player make the choice?
What is the result of the choice? How will it affect future choices?
How is the result of the choice conveyed to the player?
Each of these stages represents either an internal event, in which the system of the game processes and receives the choice, or an external event, in which the choice is represented to the player.
The space of possibility of a game is the space of all possible actions and meanings that can emerge in the course of the game. This concept ties together meaning, design, systems, and interactivity.