Space game in futuristic feudal society, there are several organizations, each player belongs to one (obligatory). Designed to work with 100-300 active players (probably for hardcore players only, but who knows...)
Organizations:
4 noble houses (military)
3 corporations/guilds (commerce)
The struggle is on 2 layers: military (houses) and commercial (guilds). Players of different layers do not compete. You have a military control of a planet, fine, someone else took the biggest market share on it, it is not your problem and it does not concern you. The same goes for guilds, you just make business, wars made by noble houses is of low interest to you (unless you can make a profit from it).
There are separate rankings for houses players and guild players. Players from other layers are never perceived as enemies or competition (but could be perceived as friends in some cases).
Players from the same house can not fight (some exceptions?). Players from the same guild can compete (they just have more deadly options available for competitors that are not from their guild).
Planets are the focus point of the game. These are "owned" by house players. Guild players can build their commercial facilities there. House players set taxes, these are paid by guild players on that planet. House player can give exempt from tax to any guild player.
Offices are the second focus point. These are again completely separated into house/guild player offices so no competition between layers. There are 3 types of offices:
- shared among all players (but 2 separate pools for houses & guilds)
- shared among players of the same house/guild (like "Head of the Noble House", "House Elder")
- given to whole organizations (like one house can earn "Imperial House" title if one of their members got elected to be an emperor)
Competition & interaction:
- players compete for the best score within their layer (houses/guilds), which is the ultimate goal of the game
- players compete within their house/guild for position and priviliges (it is best to be in small organization since the amount of these is equal to all houses/guilds but the competition is lower in smaller ones)
- players want their house/guild to be stronger than other organizations (it would give them some bonuses, maybe like top 10 players from a house add their fleet power to the common house orbital bonus), especially they would prefer someone from their house to hold a precious office than the other house (of course it would be better if they hold it themselves, but if you don't have what you like you like what you have...)
- players from other layers can support the other layer somehow (like tax, services, trade... need ideas here)
- maybe house could make an agreement with a guild, which would affect all players in both organizations?
- guild players collectively affect prices of military units that are paid by houses (if they collectively do good and have a lot of factories then houses pay less for the purchases (the money do not go to guilds, these are just price changes))
- from time to time there are alien invasions, houses try to stop these collectively. If failed then houses suffer minor penalties, but guilds suffer heavy penalties (so guilds will root for the houses success and would very eagely look for invasion news even though they could do absolutely nothing themselves

)
Questions:
- where are the weak points in this design?
- ideas for more non competitive interaction between houses and guilds
- ideas for competitive interaction of houses/guilds within their layer
- maybe players should be allowed more than 1 account?
- and your other thoughts...