Finally managed to put a recent discovery to use in a defense. A goblin axe lord was making his way into the fortress, blocking effortlessly every bolt sent his way, he's running down the final road into the fortress to slaughter the elf traders. The ballista is poised, it is on the other side of the depot, putting the elves in the line of fire, but who cares about them, if he gets any closer the operator is told to fire anyway. The military is underarmored, that lone axe lord could decimate the fortress.
Then this happened.
The Goblin Axe Lord jumps away from The flying {*donkey bone heavy bolt*}!
The Goblin Axe Lord slams into an obstacle!
The spinning -menacing birchen spike- strikes The Goblin Axe Lord in the upper body, bruising the muscle and bruising the right lung through the ({*small copper mail shirt*})!
The Goblin Axe Lord is having trouble breathing!
The axe lord dodged into one of the the 2 z level pits on each side of the road landing squarely on top of the upright spikes placed there for just such an occasion. I had expected the wood to do nothing to armored opponents, the metal ones were in the pit closer to the trap line, the wood ones were mostly just there to look nice and fill the rest of the hole.
I'm just imagining this epic godlike goblin, shield raised high charging the gate as elves flee before him blocking bolts like some matrix movie badass to
ominous Latin chanting, dodging into the air over the pit with a flip, then doing a Whil-e Coyote thing as he hangs in the air for a second realizing he screwed up.
In other news, fortifications no longer seem to protect defenders from goblin arrows.