So i'm in a world gen where there's multiple necromancers wandering around, in my first fort it took less than a year to be attacked by a necromancer and being sorely unprepared, got destroyed. I.e i had two decently trained hammerdwarves who crushed every bone in 4 of their bodies and then they got tired and basically got killed cos of that.
So i decided to relocate nearby, this time, plan is, is to use water to push them into a drop and hopefully hurt them/drown them.
Facepalm #1, i selected a region which was 37 z levels deep, the cavern taking up most of around z11-z13. So max drop i had was about 10.
Facepalm #2, Whilst digging the hole, the miner got stuck. I decided this was somewhat easily fixable, he can just tunnel his way to the surface away from the fort itself, so that if invaders really wanted they can keep doing a circuit of being pushed down a hole and walking back upto surface.
Facepalm #3, A giant Toad wanders into my meeting hall. i was like WAT? trogoldytes completed ignored the stairs. Giant Toad runs into my meeting hall like a freaking immigrant! thankfully my hammerdwarf took care of it in 3 hits.
Facepalm #4, A GCS now runs into my meeting hall, and kicks the flying heck out of everything.
Facepalm #5, I have a trapper and could have simply placed 1 single trap on the way up to avoid this sort of thing, and would then have a GCS to fight against the zombie hoard. Oh well.