Is there a point to having more than one domain?

Question

My group was using the rules to create our own house which includes determining Land Holdings. In the example given they state that it is unwise to invest all your points into a single domain.

However, I see no reason not to. It is clearly stated that there is no limit to the number of features you can add to a single domain and you can also have any number of defense and wealth holdings in a domain. This also makes having a single domain easier to defend.

The only benefit I can think of is having access to different types of terrain but in our case, with the the realm being the Reach, the only available kind of terrain is plains.

Did we miss something or is there really no point in having more than one domain in this case?

Answer 1

Yes, there is: Warfare

Your house is in deep trouble if you have no domain left after being defeated on the battlefield.

If you cannot afford to invest in a domain, your holdings are smaller than a league and extend out around your primary stronghold.

Without lands, your defenses are also gone (except for the primary stronghold):

To gain a defense holding, you must have at least one land holding.

There is also another advantage of owning more than one domain, such as having more than one type of terrain available (you are limited to one type of terrain per land domain - core book, page 107).

For instance, if you have a domain in Dorne, you are limited to Hills, Mountains, Plains terrain types. If you decided to create your first domain without a coastline (or it was decided for you by the GM), there would be no way to build a Port without acquiring a domain that has a coastline first. Similarly, without Hills or Mountains, it's impossible to build a Mine, which is the case for the houses with domains on The Reach or King's Landing (both only have Plains terrains available).

Even if your initial domains are in The Reach, which only have Plains terrains available, nowhere in the setting says you are limited to only obtaining new terrains on that same kingdom. Yes, you could attack adjacent domains and move your way out of The Reach, or send troops to attack distant domains and claim ownership of them.

Also, though not really important to the house, it matters when travel speed is important. Owning terrains on Wetlands, Hills or Mountains are actually a hindrance to characters who must travel at half speed (for Wetlands and Hills) or slower (for Mountains) while getting anywhere within your domain. Which means that Plains terrains are the best for traveling. Roads do make this slightly better though.

Mountains without roads also do not allow you to use Cavalry units on the battlefield without spending Destiny Points for each order given, which is ok if you are defending your communities, but maybe not if you are defending other areas. Mountains also do not allow you to use any Siege Weapons, regardless of their position in battle, meaning that defensive structures are much easier to defend.

Other than that, there is really little point in owning more than one domain, or even having more than one community within your domain. Smaller domains are much easier to defend aswell when troops don't have to travel around. But all that is something that is affected more by narrative than game mechanics.