That's good to know and definitely deadly, but for the sake of mass murder I feel I must still try to make a case for negacaps (name subject to change
). Before the save got corrupted, I was building this:
If the pic isn't clear, you make the moat a road into your base that's a few z levels down and ~3 across, then you dig a tunnel underneath it 1 tile deep and ~5 wide, run raisable drawbridges length-ways down the middle 3 tiles and connect them to levers. Fill the tunnel with magma and then the bottom z level of moat with water. Bridges up atom smashing magma = water frozen, bridges down = water melted by returning magma causing everyone on the ice to start drowning, bridges up again = drowning baddies get encased in ice instantly.
The downsides to it were that it required a constant magma flow, water source, with
many magma-safe mechanisms and bridges, and that it had to be outside and uncovered (a freezing volcano made it easy). No pumps or anything required, you can even do it in vanilla, just a lever pull to make a path at any length/width you like kill anything on the ground, by either drowning or getting encased in ice. You'll need to drain the water to a safe level if you want the drowned goblinite, but not 0/7 so you can refreeze it to 7/7.
In theory it should have worked, as I know others have done similar stuff, and I'll probably try again in the future - but I'd love to kill flying baddies in similar ways and see what other people come up with, like pressurised vetical variations. Pretty please give it some thought?