The other night, when I tunneled out from behind my butcher's shop to setup a couple of grates so that miasma wouldn't completely fill up my corpse locker, and lo and behold, the moment I breached the outer wall 'A Vile Force of Darkness has arrived' wtf, like 10 squares from the hole in the back of my fort.
Lots of people died, tantrum spiral, bad things.
Similar incident happened to me in a fort last night- luckily I survived.
Except I didn't realize I had the 'hole' until some orcs made their way through it! (dig deeper)
It was a 1-wide wall they could walk on top of from a cliff. I was in the process of removing the ramps that provided access to the the hill that touched the wall but that was more so they could not shoot down from that hill- I didn't realize they'd walk on the wall. The wall lead to the roof of my main fortifications and then a staircase down into them. From there a bridge across to the mountain my fort was built into or a set of stairs down into a lower level of the fortifications many connections to some access tunnels.
It was a 4 or 5 squad siege and thank god I had my archers in the fortifications- they had killed all but two of the orcs before that squad got on the wall. My other troops took care of the last two before they caused too much trouble but I was all aware of the 3 more orc squads on their way to my design flaw.
I sat paused for literally 5 minutes trying to plan what to do... At first I designated a mason to build a single wall section to block access- but I (thank goodness) realized it would take way too long and he would get scared off by the nearby orcs anyways. So I rushed my miners to the fortifications with some random dig orders in the area while I positioned my troops in the fortifications as a last defense. The miners got there quick enough that I was able to dig a two tile channel blocking the bridge that made connection to 'my hill' (It was not set up to any levers- never thought I'd need to raise it- it was mostly just a cheap/fast way to construct a floor over a couple tile gap).
At the same time I ordered my army out of the fortifications and
tried to keep everyone else out- but for some reason the stupid miner that dug the channel decided to stay, and a peasant came into the area to drop off some ammo in a stockpile... sucked to be them... I had another miner dig out (thank god it was a mined staircase and not built) the stair that lead down another level in the fortifications just as the orcs started swarming down from the roof into the level above. The miner and peasant were quickly swarmed by the orcs and killed- one sent flying 15 or so tiles to land next to my army on 'my' hill that were standing watching (which conveniently let me bury him- the other guys body is still in the fortifications).
So I was able to successfully recover from my design flaw (which would have ceased to have been a problem had the orcs waited another half minute or so before coming) at the mere expense of a miner and a peasant... Problem is that it left me with no defensive positioning besides my flood chamber... Those fortifications were essentially my last line of defense (I only realize that after the fact, of course) because once past them there are like six different ways into my fort- and once in my fort its like being in the EU, you can get anywhere from anywhere.
Oh well.. tonight I'll return to the game to see if I can drive the siege back.
And had they made it past the fortifications and into the fort and killed everyone? no save scum for me... that's part of the fun:-)