From BrWiki
Anarchy is an unusual state of affairs. When people are in frequent contact, they make rules to govern interactions, starting with who is in charge. This could be as sophisticated as forming a common assembly or as fundamental as acknowleding the fellow with the big sword as the leader.
For a period of anarchy to last more than a few hours or a few days one or more conditions need to be present.
Rivals
When there are two or more powers competing to be the authority in a place, they may produce a zone of lawlessness between their two camps. This is possible because no one can agree about which law to use to solve problems, because everyone cleves to the law which favors their case. For certain, this kind of anarchy is accompanied by violence between factions, as the only way to settle problems in the absence of law is by force. This situation might be described as civil war if it visits itself on a large enough scale. Otherwise it is probabaly described as a feud.
Irresponsible Master
Another possible cause of anarchy is a leader who takes no responsibility for the welfare of his people. A ruler who does not wish to be bothered solving the problems of his people, which they cannot settle themselves, is leaving them to feud.
Recent Loss of Authority
People become accustomed to authority. If everyone expects a certain outcome to a legal issue, even if the authority that once guaranteed such results is gone, that result is pretty likely. At some point however, the especially bold, greedy, or anti-social will defy tradition and test what remains to back up its expectations. When this begins, anarchy has replaced the decline of the old order. It will last as long as no new authority challenges those willing to defy the law. An especially long anarachy can be produced by having this state of affairs followed by Rivals or the Irresponsbile Master.
Anarachy is not a happy state. A dying man has no way to pass on his lands to his heirs. There is no way to prevent them from fighting amongst themselvs, or from preventing outsiders from simply comming along and taking what was his. Criminals are free to act, because no one restrains them. The strong are a law unto themselves, and may protect their followers, but prey upon everyone else. Force and violence is the only defense against the force and violence of those who would do you harm and take what is yours.
Freedom is a happy state, but it is quite different because transfers of property and other interactions can happen without force or immediate threat of force. This is because there is always some threat of force, but it comes from a distant authority instead of the two parties attempting to interact.
