Bay 12 Games Forum

A menacing spike trap should also work, and is a bit easier to set up than a cave-in since you don't need more than 1 Z-level to work with.

how many mechanical systems would it take to hook up 5 cages to a lever?

Building a lever requires 1 mechanism, and linking a lever to a triggerable object (in this case, a cage) requires 2 mechanisms - one for the trigger, and one for the lever itself. I'll let you do the math.

In the beginning, all stone. After a few decades, though, I'm considering replacing them with metal (have over 700 iron bars, and an entire patch of magnetite I mined out and haven't smelted yet) or green glass (yay unlimited building materials). Important doors get made out of more valuable materials, such as clear glass or valuable metals (artifact museum has platinum doors).

Maybe it's just me, but the icons for happiness are rather difficult to tell apart (though in my current fort, nearly everyone is ecstatic with only a few that are less happy). Having different colors (in addition to the different facial expressions) would allow telling them apart more easily, perhaps starting at green or blue for ecstatic and working toward red for miserable.

Was construction actually completed on the wall?

One bar makes 25 bolts, and melting stuff down generally gives significantly less than what you used to make it.

Fire imps do not respawn, nor do any other creatures inhabiting a magma pool/pipe (excluding fire snakes, which are vermin and follow their own rules for movement). Personally, I got rid of mine by dropping a large stone pancake through the top of the vent while they were hanging around directly beneath it (see video here).

Actually, magma pipes refill gradually by "bubbling" magma up from the bottom (thought it really fills from the top) - every so often (at least once per in-game day), a column of 7/7 magma several tiles tall (up to 3 or so, but not beyond the top of the pipe) will be spawned at the current magma surface where it will then spread out.