Game design ideas gain value, sophistication, and meaning only when they are playtested. The hard work of the process, the actual game design itself, happens during the iterative process, not the concepting process that proceeds it.
Quotes by Eric Zimmerman
Play. Games. Narrative. Interactivity. What a motley bunch. Honestly, have you ever seen such a suspicious set of slippery and ambiguous, overused, and ill-defined terms?
In other words, the important thing to ask is not What is painting? or What is game design? Instead, the real question is: What is gained and what is lost when we define it in a particular way?
Rules might not seem like much fun. But once players set the system of a game into motion, play emerges. And play is the opposite of rules. Rules are fixed, rigid, closed, and unambiguous. Play on the other hand is uncertain, creative, improvisational, and open-ended. The strange coupling of rules and play is one of the fascinating paradoxes of games.
Games are not interactive stories; they are not formal systems of rules; they are not the personal expression of the designer—they are all of these things simultaneously and many more.