Eric Zimmerman spoke eloquently on games as the second day keynote at DevLearn. In it, he talked about how systems thinking was important, how games are systems of rules and consequently develop systems thinking. He talked about how our play brings meaning to the rules, and that creating spaces of possible outcomes allow us to explore.
He ended up advocating that we design for possibilities of unexpected outcomes to create meaning for our learners. Cammy Bean has blogged the presentation too.