I would have used this concept for my own MUD, but I'm bad at runnings servers and all that computer-based stuff, so I guess I'll just hope some MUD coders and builders will see this idea and start a cool MUD.
I would like a MUD where you play as a the ruler of a kingdom. Basically you start in your Homeland, which is a safe little place where no uninvited ruler can enter. Pretty similar to the home planet in Gods War II. At your Homeland, you can build structures such as Farms (produces crops, which can be harvested if you ask your Agricultural Minister to harvest it), Barracks (turns Citizens into Soldiers if you ask your General to train new Soldiers), Theatres (Increase the kingdom's population satisfaction, lowers employment rate), Shops (increase your kingdom's wealth periodically, depending on how high your tax rate is, but remember that a higher tax rate will result in lower population satisfaction, resulting in the exodus of several citizens) et cetera, as well as interact with your unique court ministers and give them orders. The Ability of these ministers will affect how well they perform the orders, so sometimes you will have to fire ministers and hire new, better ones.
Meanwhile, there will be a huge Realm that is open to all kingdoms, and which will also be the site for many massive battles. Kingdoms can conquer parts of this Realm through warfare. Every grid in the Realm has an x and y coordinate, and are used to determine which grid your soldiers will attack. Meanwhile, DIPLOMACY commands are just a sign that you won't attack the certain kingdom, but can be broken as long as you send your soldiers to that kingdom's territory in the Realm.
deploy <amount of soldiers> to <realm coordinates>
withdraw <amount of soldiers> from <realm coordinates> to homeland
The server will know if your deployments are for attack or for defense by checking if the soldier's destination is owned by your kingdom or by another kingdom.
Grids on the Realm possess different benefits, such as increased wealth gain or faster troop production. There will also be several Special Grids which possess HUGE amounts of benefits, and will probably be the location of gigantic battles between rival kingdoms. Besides that, there is a Kingdom Ranking where kingdoms are ranked according to the amount of land owned in the Realm. Also, to prevent kingdoms from monopolizing the entire Realm, if a Kingdom owns more than 1/100 of the entire Realm, their future attack power is reduced to 1/3 of the original attack power. So basically 3000 of their soldiers will be equivalent to 1000 of other kingdoms' soldiers.
LOL it sounds like I'm advertising my own MUD. Well I'm not
Just a note to the future creator of this game: Remember to give me in-game benefits as well as entrance to early beta. Yeah. *laughs*