Game Design
[http://www.ted.com/talks/stuart_brown_says_play_is_more_than_fun_it_s_vital.html Importance of Play TED talk] by Stuart Brown. Read Theory of Fun [http://www.gamasutra.com/view/feature/2173/book_excerpt_a_theory_of_game_.php 1]
State of flow: characterized by increased focus
Caillois' forms of play
[http://www.ted.com/talks/mihaly_csikszentmihalyi_on_flow.html “Flow” TED talk] by Mihaly Csikszentmihalyi.
Flow conditions: