In case of a war, an official declaration of war should be made up, stating some basic rules of combat. Representives from both Kingdom/Guilds with the right to agree or change some of the things in the declaration and should be able to work with the authority of the GCs and have the power to change some of the items without having to consult the GCs. Yet the Representive should inform the GC of the changes and also supply the GC with a copy of the log from the meeting between the representives of both Kingdoms/Guilds.
There are two types of war, conventional and guerrilla. Each will be discussed. War can be declared for about any reason you can think of. It might not be approved but it can happen.
When one Kingdom/Guild or person does something to insult, humiliate, or anything else to another person or Kingdom/Guild, any of the following actions can take place: an HM, take it to the Forum to try and have justice done, declare war, or something else that works.
War can only be declared by a Kingdom/Guild and has to be declared on another Kingdom/Guild. So if only one member is the cause, look for other means.
Once war is declared the Kingdom/Guild declaring it must write up a Declaration of War and present it to the Forum and to the other Kingdom/Guild. From then on it can go two ways:
The Forum can approve the war and the Kingdoms/Guilds can also approve it. If that happens then either conventional and/or guerrilla war can be fought. If the Forum or the other Kingdom/Guild doesn't approve then only a guerrilla war can be fought. If both the Kingdom/Guild and Forum disagree with it then another way to settle the problem will be decided. War like tactics are not recommended then.
Conventional war is simple. Once the Kingdoms/Guilds are ready to fight, 10 members from each Kingdom/Guild meet in a room with one witness for each side and have a mass DM. Once you die you leave the room. When a Kingdom/Guild member is killed another one can come in and take their place. At the beginning of the battle a member from each side rolls to see which side goes first. After that each side takes turns attacking. How they decided the order is up to them.
Guerilla war is a lot different. There is no set meeting place or groups of people. This kind of war is filled with AA's. Mass AA's are allowed at this time and are recommended. Also normally what would get you in trouble would be allowed, such as jumping someone. This type of battle can go on until one side decides they have had enough and surrenders.