Mihály Csíkszentmihályi ("Chick-send-me-high") identifies nine factors that accompany the experience of flow in a practice or process, i.e. a "game":
1. You are clear about the rules of the game and your expectations of it—and your goals are achievable.
2. You find the game neither too easy nor too difficult (= a balance between skill and challenge).
3. During the game, you focus closely, i.e. intently and narrowly, and . . .
4. . . . adjust your behaviour immediately in response to moves in the game (= an uninterrupted feedback cycle).
5. As a result, you experience a merging of action and awareness, that is, . . .
7. . . . in control.
8. Thus, the game feels timeless and . . .
9. . . . effortless.
Flow is thus ecstatic (ek-stasis: "outside-standing," i.e. standing outside, or rather, to one side of the everyday world and your everyday concerns) and engaged (en gage: "under pledge," i.e. fully committed to a task, knowing exactly what to do and how to do it).
Csíkszentmihályi conceives of flow as developmental: all going well, you can stay in the "flow channel," in which challenges and skills increase together by increments. This diagram is adapted from Flow (1990, 74):
See "Play and Intrinsic Rewards," Journal of Humanistic Psychology 15 (1975) 41-63 and Flow: The Psychology of Optimal Experience (New York: Harper & Rowe, 1990).