Applications
Understand whether you're in one-shot or repeated game. In one-shot interactions, cooperation is risky. In repeated interactions, cooperation becomes rational because reputation matters. Structure relationships for repetition to enable trust. This applies to business relationships, partnerships, and communities.
Build reciprocal relationships by cooperating first but retaliating if betrayed. Be nice, be retaliatory, be forgiving, be clear. This combination of traits outperforms pure niceness (gets exploited), pure nastiness (prevents cooperation), and randomness (creates confusion).
Recognize when strategic interaction requires coordination rather than competition. Many situations are positive-sum where cooperation benefits everyone. Don't reflexively compete when cooperating produces better outcomes for all parties. This requires trust but generates surplus to share.
Use commitment devices to enable cooperation when trust is lacking. If both parties worry about defection, mutual commitments solving coordination problem allow beneficial exchange. Escrow, contracts, and staged agreements are commitment devices making cooperation possible between distrusting parties.