Now I have always felt that the best part of !!Science!! is in the monstrously dangerous constructions we devise to outwit, outprepare, or just outsmash our enemies (or non-useful friends).
I didn't see a thread for general discussion of these marvels of dwarven ingenuity, so I present a design I have never tried and I ask that you guys try to think of why it might not be viable. It's for the clowns.
Green is retracting drawbridges; I aim to close one to make the labyrinth the only way from mine to fortress when the time comes.
The labyrinth on the right has only one path and will be full of bears to slow clown progress a little to allow stragglers to enter before the quicker ones reach the fort.
Yellow is supports whose activation will produce "results".
Pink boxes show where a tunnel will have constructed roof and floor, but raised drawbridges instead of walls (because walls don't break so well when you drop stuff on them.)
The ideal result is that the labyrinth falls, smashes everyone in it, and breaches a container of water and a container of magma to encase all the resulting mess and give my dwarves something to engrave afterwards. Then I might drop hammers on it all, but it might be dead bodies, eggs, children, more bears or whatever. Then I'll drop the that container onto it all for good measure.
I would be grateful if anyone could identify flaws in this design (other than FPS death when they all try to path through the labyrinth), and I'd love it if others could submit their own interesting designs for special weapons in this thread also.