Cheexsta wrote:By that argument, there are no codices that have been specifically made redundant and so all printed codices are legal. Yay, Squats still live!
Not quite true. Previous
FAQ's have rendered certain codexes or lists redundant over the years, particularly in the case of the 3rd edition sub-dexes that were designed to work with a 3rd edition parent codex.
While there's no RAW argument for it, it's hard to justify using a codex that is no longer in print.
That would stop people from using Daemon- or Witch Hunters, and most likely Necrons as well...
There is nothing (outside of tournament or league play that lists exactly which books are in use) that says you have to use a codex that is still in print, or even that you have to stop using a codex when a newer version is released.
However, using any of the 3rd edition sub-dexes is going to run you into some issues, largely because both their parent codexes and the core rules have changed, so they will require a certain amount of tweaking in order for them to work with the current rules. If you and your opponent are happy to do that tweaking, I see no reason to not use whatever codexes you want to use.
So to return to the original question, if the asset makes a terrain feature Dangerous, and Catachans treat that terrain as clear, then the asset will have no effect on Catachans.
Note though that the Catachans' terrain rule actually only allows them to treat woods and jungle terrain as clear for movement. Other types of terrain (ruins, for example) are not affected.