We recently released the Kingdom server. The point of the server is to give power to the people to decide how the kingdom will be run; a roleplaying server.
The default rank is the peasant. The peasant has to toil and gain money in the dangerous world. PVP is enabled everywhere so without order all peasants would kill each other. To gain more power and to lower the tax rate (taxable blocks disappear and get converted into money for the king, for peasants the max tax rate is 50%) the peasant can rankup to resident for $10,000 at spawn. The area outside of spawn and away from the roads has building enabled.
The resident can be upgraded to a higher rank by the king and has a lower tax rate (a max of 25%). They can also rent protected land in the castle.
There is one player who is a king. The king has a lot of power over the other players of the server. In particular the king can set the taxrate for peasants and residents. He can also activate server wide bonuses, set builders (to improve the area around spawn) and set knights to enforce the rules and to maintain his own power. Both the king and the knights have more health. The king and the knights can also make normal players wanted - on death a wanted player will be sent to prison, where they have to mine a certain amount of diamonds to get out.
If a player is against the king or doesn't want to pay the tax rate they can desert the kingdom via /desert. By doing so the player gets a red name and on death will be sent to the prison with the maximum reward. The current standing king can pardon anyone in the prison (/unwant).
The Church is the only area in the entire map with no pvp (/coords). The Town (/coords) has goods that you can buy low and sell high at the spawn castle. The town is near the rebel base so it is fairly dangerous to go there (rebels are usually not nice). However a good trek and up front investment can lead to $15,000 in profit per trip.
There are no rules on Kingdom; only the rules set by the king. If the king wants to enforce them he has to send the knights to do his bidding. However, if players dislike the reign of the king, they can take matters into their own hands and fight for the throne. There is a KOTH at the coordinates 0,0, in the center of the castle, that lasts for 15 minutes. If a player manages to stay on the throne for that long they will become the new king and all previous knights, builders and bonuses will be reset. In this way there is a balance of power.
Have fun! We don't know what the server will lead to yet but it will be interesting to watch. If you have any suggestions / bugs, please let us know!