...Play is an activity which is essentially...
1. FREE: in which playing is not obligation; if it were, it would at once lose its at- tractive and joyous quality as diversion; ( in your project is observation simply enough? Or are you striving for a more active participation?)
2. SEPARATE: circumscribed within limits of space and time, defined and fixed in advance (how to you ascribe your magic circle? What are its bounds? What is the temporal experience? How do the two relate?)
3. UNCERTAIN: the course of which cannot be determined, nor the result at- tained beforehand, and some latitude for innovations being left to the player’s initiative (uncertainty here does not mean you create without intention; uncertainty refers to the outcome of the system you have created into which the audience freely interacts)
4. UNPRODUCTIVE: creating neither goods, nor wealth, nor new elements of any kind; and, except for the exchange of property among the players, ending in a situation identical to that prevailing at the beginning of the game.
5. GOVERNED BY RULES: under conventions that suspend ordinary laws, and for the moment establish new legislation, which alone counts; (by this we mean a departure from the everyday, but not breaking or disregarding laws of safety or respect. Secondly, consider the rules of the system you create: how does someone enter your circle, what do they do there and how do they know what to do?)
6. MAKE-BELIEVE: accompanied by a special awareness of a second reality or of a free unreality, as against real life.
from Roger Caillois,The Definition of Play, The Classification of Games