On page 6 of the tournament rules, there are rules for using existing 3D terrain. Our locals love this, and the store has plenty of suitable terrain, so we've been using these rules.
Many of the coolest terrain pieces we have are buildings. Unfortunately, I've found them very difficult to make appropriate rules for. The tournament rules are very vague on this subject: "The organizer should also assign each piece of terrain no more than two keywords based on its physical appearance, clearly labeling the terrain for the tournament. (Terrain keywords can be found in the “Terrain” section of the Runewars Miniatures Game Rules Reference.) The organizer may also need to set X values for these keywords." Looking at what keywords are available, it seems like a building should provide protection against both ranged and melee attacks; it should provide more cover than trees and at least as much fortification as a wall. So my first instinct is to set it at Cover 2, Fortified 1.
Unfortunately, this makes it really overpowered. We've tested buildings in that range, and if someone like a high-armor Hawthorne build with a Shield of Margath gets in there, there's no way to do anything to him. In a scenario like Bounty, where all the scenario points are on one model, this feels really bad for a tournament setting.
If I could make up a new terrain keyword for buildings, one that would be both flavorful and help with balance would be something along the lines of "Cavalry and Siege units cannot occupy this terrain, nor can units with a Heavy upgrade." This would represent only being able to get in through doors (as riding a horse into someone's house isn't happening, not to mention trying to get your Rune Golem in with you) but also disallow every powerful unit I can think of from ever entering and gaining the powerful advantage.
However, the tournament rules do not allow for this. For one thing, you can only use keywords from the book (so you can't even grant abilities that aren't keywords, like on many of the terrain pieces that have come out since the core set) and for another, even if this keyword existed, it would bring this terrain up to 3 keywords. Obviously if the locals are all cool with it, I could bend these rules for small tournaments here, but when we host store championships and (hopefully) regionals, I'll need to stick to the rules in the tournament pack.
So we're left with this; what keywords should we use for buildings? Or should we just avoid using them, even though they look great? Any thoughts?