A game is strongly emergent if its frame permits a high degree of discovery, especially of the kind that the game’s designers never foresaw. Unusual strategies, innovation and creativity are enabled, and in some ways the game maker feels as much a participant in the discovery of the game as the creator of it.
The objective of developing an emergent frame is a system in which a limited set of actions and rules produces a near infinite set of outcomes. Emergence is therefore a key trait of tetrist and simulationist games, although each approaches it differently. In a tetrist game emergence comes from from a few highly extensible actions, whereas in a simulation it comes from the interactions of complex and authentic rule systems.
The opposite of emergence is experience.