An alliance costs 10,000 gold to start. It has 20 members by default but can have members added by purchasing space with gold and gems. Alliance members will be able to send resources to each other. Whenever a member of an alliance purchases 125 or more gems all at once all members will recieve a gift. The gift depends on the package purchased. There is one leader, and when a member is recruited they are called "general". You as leader can appoint them at minister.
General's rights/responsibilities: The general class of the alliance is the rank you get when you first join, and the lowest class. General players can donate to the alliance and post a topic on forum every hour. The general players have no set responsibilities, but can contribute to the alliance by donating.
Minister's rights/responsibilities: The minister is the higher class of the alliance. The minister can do everything a general member can do, and more. The minister can see the troops of all alliance members (including the president's), so make sure you can appoint one you can trust. Next, the minister can change the alliance bulletins and kick any general player they want. The last thing a minister can do is change the alliance recruitment status and points required to enter.
Alliances can support, or wage war with one another, as well as fight for capitols. Alliance score is approximately one tenth of it's members total score, but does not always mean they are the most powerful alliance, as alliances are constantly brushing up against each other, and one failed capitol battle can deplete more than half the alliances total troops.