sooner or later, it is necessary to adapt the rules for using a common property resource because of changes in the social system or the ecosystem, changes that often originate from the ‘outside world’. The mechanisms for adapting rules should be simple and inexpensive.
Changes should usually be incremental so that large mistakes are avoided.
It is important to monitor carefully what happens after new rules are put into effect, so the group can decide whether to make further changes.
Trial-and-error evolution of rules is an example of self-organization in the social system.