Undead pathing is badly broken. If you're lucky they will drift aimlessly for a season before running away, and if you're unlucky they will drift for a year. I had one group that never came more than 15 tiles from the corner the entered at for the season they spent milling around before leaving.
There are two passive ways for them to stumble upon your fortress:
- Some of them chase some local wildlife and happen to come close enough to you to catch the smell of dwarfs. Those who catch the smell will charge your fortress, but undead do not seem to communicate, so they won't bring any buddies with them.
- Their drifting accidentally bring them close enough for some of them to smell dwarves and those proceed as per the above.
Note that "close enough" is very close. I've had them up to my walls and even one step into my entrance corridor without them reacting. Two steps in, though, and they run.
There are a number of active ways to draw them in (I haven't practiced any of them, though):
- Tie up some sacrifical animals in a chain from close to them all the way to your fortress entrance. If the animals are close enough the drifting should cause some undead to smell them and thus slaughter their way along the chain. It's entirely possible that the whole sacrifice will net you a single undead, though.
- Send your militia out. That will usually lead them to be slaughtered, since the undead probably outnumber the militia significantly.
- If the undead split up into groups, send out the militia to attack a small isolated group. A very high risk venture, since your militia may easily get too close to other undead groups and get slaughtered. Militia dorfs have no sense of self preservation and ignore all orders to retreat once the see an enemy they think they can reach (Xbow dwarves generally think they can't reach any enemies they can fire at but cannot reach physically if it involves moving a single tile).
- A proposal is a bunker chain, where little huts with fortifications and access from below only allow you to entice the enemies to approach. By using drawbridge shutters and bunkers close enough to each other you might be able to lead them to you. There's a high risk that the dorfs in the bunkers get shot by arrows and/or bolts, though. Double fortification walls might reduce the risk.
- If you know where they enter the embark (which you probably don't since by the time you detect a pattern they've run out of steam and won't be seen any more) you can build retracting drawbridges along the edge the enter to drop them down either into a sea of traps or just to get hurt from the fall and to split them up into groups small enough for the militia to handle. I've actually used this method, and it works well against the regular goblin attacks (the undead haven't shown up for 20 years, though).
- Send a sacrificial civilian out on some errand to get the undead to chase it. That's very hit-and-miss, because running undead are fast, undead use missiles, and panicky civilians will run away from the threat, not towards safety. Thus, a very high risk of losing the civilian without bagging any undead.
- A rather safe method, given the pathing ineptitude of the undead, is to build an array of ballistae on the other edge of the map (or halfway across) to try to fire in the general direction of an undead horde group. You may hit some, and possibly even score a kill, which would allow you to pick up some goblinite and underwear after they've left. Very unlikely they'll react to being attacked (campers can be shot down this way, without reacting to getting hurt), but I haven't actually tried it with undead (who aren't EXACTLY camping, just almost). Fortification walls one tile away from the ballistae will provide some protection from missile fire and will protect the ballistae from building destroyers (such as trolls used by goblins), provided, of course, that the wall is complete and there is a roof. Access should be from below (building destroyers smash doors...).
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Topic: Zombies doing nothing (Read 422 times)