[MaxWilson]

I happen to agree with Sombre, not because I mind site-searching but because horror marks are incredibly weak (which is why the B9 bless is awful). If your mages at some fort have a 5% chance each turn of getting +1% chance per turn of a horror attack (likely to result in a horror attack in about 70 turns), you may lose a couple of mages over the next 40 turns (gcost: 500 or so), which isn't enough to bother relocating a fort for. I made those 5%/1% numbers up but IME they're ballpark-accurate; horror marks are more frightening than deadly unless they're STRONG or you like to cast Call Horror in battle. Of course if you lose a PRETENDER (as opposed to research mages) to Horror Marks that's a different level of pain.

-Max