Bay 12 Games Forum

Enemy units will not step into magma, but they won't avoid it much beyond that (i.e. they'll stand right next to a tile of 2/7 magma even though it's about to spill onto them).

From my own experiments with magma entrance traps, this is how it works out:

 * Enemies enter your trapped area
 * You lock them into the area, and start releasing magma at one point.
 * Enemies haven't realized they're trapped inside yet, continue running down their path to your (now-locked) entrance
 * Enemies realize their next steps would land them in magma, and stop, confused.
 * Other enemies realize the way forward is blocked off, and just stand around aimlessly.
 * Magma eventually encroaches and burns them all down.

Only civilians will be frightened by dangerous creatures - soldiers and guards (and invaders) aren't afraid of them

That would be the "permanent effect pressure plate" system in the wiki article I linked above.

1. Fall damage varies by creature size, and is also based on a significant random modifier.  I'll use elves as an example because of a delightfully successful experiment I had with a bridgeapult yesterday.

1 z-level only rarely causes a broken bone, but seems to always stun the creature.  This was true for all elves who were flung through the air, their goods scattering to the four winds like popcorn, and then dropped 1 z-level.  2 or 3 causes significantly more damage, as demonstrated by one of the elves' mules which fell 2 z-levels into my dry moat - it sustained two broken legs, a broken ear, and several brown and light-grey wounds.  The poor fella was left for dead by the disgruntled elves, even though it was perfectly capable of hopping about on two legs.  It probably didn't hear them calling, since its ear was broken.

2 and 3. Caged creatures do not act as wards... though this is a pretty neat suggestion!  You could, however, cage a bunch of bears or something and use it for building-destroyer deterrent.  A troll smashes your terrarium only to find himself confronted with 20 grizzly bears... *jots that one down*

Another alternative is restraining an animal, though in my opinion they aren't that useful.  The animal will only be able to move one square away from the restraint, meaning it's toast if enemies shoot at it.  You could build some walls against its vulnerable side forcing the enemy to get close to it, but even then it's risky.

Enemies can and will shoot into barred cages (wooden or metal).  I don't know about glass ones.  But you could leave some barred cages outside with spare animals so that the enemies waste their ammunition on the cage instead of your dwarves!  *jots that one down too*

4: What you're envisioning won't work because pressure plates, like levers, are like on/off switches.  You can't have the same pressure plate turn one mechanism "on" and the other "off" at the same time. 

I've tried this before with floodgates, and it didn't work.  I have a waterfall with two exits, so you can toggle where the water spills out with levers.  I wanted these on one lever, so when one pair was "on" the other would always be "off."  So I connected the first two, pulled the lever so that the first two gates were "off," connected the other two, and tried it.  Unfortunately, the first two turned "on," leaving the second two "on," and pulling it again set both to "off."  I had to deconstruct the lever and start over using two separate levers.

Something else to keep in mind about pressure plates... they automatically reset after 100 steps if nothing else has activated it.  So you might want to rethink your defenses.

It sounds like you want the goblins to walk back and forth between the two bridges, changing paths to the other as the first closes.  The best you could do is dig a long, snaking path that acts as another way around the bridge.  It's longer, so the goblins will prefer the bridge over that path, but when the bridge rises they're forced to recalculate and take the longer path.  Along that path you could add traps, other pressure plates to change paths again, etc.