One thing that excites me about 6th edition is adding fortifications to my armies. Specifically, I would very much like to have a Chaos Bastion converted into a Word Bearer Cathedral to the Dark Gods. So, I've been looking into the rules for them. And, the rules seem... Well, they seem rather incomplete. Just getting started seems to require making rather more assumptions than I'm comfortable making with bare rules (weird interactions between special rules, I don't have a problem with), yet without some basic assumptions you run quickly into direct contradictions.
Okay, I'm getting ahead of myself, here.
1. Does a Bastion even have Battlements?
Nowhere in the datasheet for the
ImperialChaos Bastion is there anything about the battlements. And yet, they're clearly present on the model, and indeed they're specifically called out in the image thereof on a nearby page! So, I'm going with "Yes, there are battlements."
2. Do the Battlements count as a separate building?
This one is actually pretty simple, the rules say it does. I'm not even sure it should be a question. I thought it might make more sense if it only counts as a separate building in that you travel to and from them in that manner, but it doesn't have any such caveats. Still bugs me to have a whole second building tacked on just because I'm assuming the thing has battlements despite the datasheet.
3. What's the Battlements armor value?
If it's a separate building and can take damage (there are specific rules for that, so apparently it's a valid target if you really want to), then it must have an armor value. I'm going to assume that armor value is the same as the rest of the building, because nothing says otherwise, and bastions in general have a listed armor value, so maybe that's good enough.
4. What cover save can models in the Battlements take?
This... This is where it starts getting difficult. Once again, they datasheet says nothing. The Battlements rules themselves are even less helpful, suggesting that they might provide some sort of cover save without elucidating what the cover save, by default, might be. Anyway, the battlements will pretty easily provide 25% obscurement from most angles, so there's clearly a cover save involved. I've got two guesses: first, it could count as "fortifications", which are 3+, because it's essentially the very definition of a fortification. But... Aegis Defense Lines are also practically the definition of a fortification, and only provide 4+ (2+ for GtG), and the Battlements of the Bastion model look an awful lot like an Aegis Defense Line. On Meriwether's old rule of "when in doubt, assume the rule that benefits you least", I'm going with the Aegis Defense Line rules.
5. Can you shoot at the roof gun emplacement?
So I'm probably going to put an Icarus Lascannon or Quadgun up on the roof, for that nice free shot against incoming Stormravens before their contents fill the bastion with grenades (which, BTW, is brutal). But Gun Emplacements, despite being eligible to get destroyed from damage to their building, are apparently separate models with their own statlines, and if it's on the roof - i.e., in the battlements - then I assume that it's both part of the "battlement building" and a target in its own right (per the rules and statlines for Gun Emplacements). Conversely, it is counter-intuitively not a gun emplacement in the very building it was purchased for, so damage to the main body of the Bastion won't hurt it unless you bring the thing crashing down! Hopefully it'll get a cover save from the battlement, whatever that is.
...Heck, I'm not sure you can't shoot at the heavy bolter emplacements. I'm not at all sure if anything can/will happen to those when you throw grenades in the fire points.
6. Can units disembark from the Battlement?
A fairly large portion of the Battlements rules is given over to models embarking to the battlement. As far as I could tell, no mention whatsoever was made of disembarking from said position. By RaW, it seems to me that only the rules for moving to adjacent buildings and bloody well jumping off directly apply. On the other hand, it seems very reasonable to me that the embarkation rules should be inversable, such that models on the roof can exit the building so long as the intervening interior of the Bastion is not in enemy hands.
If there's anything I've missed, if you can shed more light on these situations, or more darkness on related situations. it would be appreciated.