How to build one-way door for dwarfs in Dwarf Fortress

Question

How to build doors, where dwarfs can enter ant can not out through?
I want to use it for 'siege time entrance' - put in end of long one-cell-width corridor with a lot of traps.

Answer 1

If you are using a current version of DF, you may just want to use the burrows mechanic, other wise this is really the only way to do it.

Answer 2

Assign a room to be a burrow. In the military screen (m), hit 'a' for alerts. Create an alert -- call it "Red Alert" or something. Build a retracting drawbridge outside the safe room's only entrance/exit. Build the lever for the bridge inside the room. May as well put some food and drink in the room and maybe a table, chair and even a bed or two as they may spend some time in there. I like to build a statue in my panic room and designate it as a statue garden. That way, idle dwarfs are already in there in case of a siege. When it's time to panic, go to the Red Alert alert (make sure you assign your safe room burrow to Red Alert). Wait for dwarves to all get in the panic room. Have one of them pull the lever. Now sit and watch as that one straggler who didn't make it into the room in time gets devoured by a giant hairy toad with an elephant's trunk!

Answer 3

I just stumbled on this ingenious trap on the wiki. I haven't done it myself, but it looks like exactly what you need. As long as you set the pressure plates to not trigger on citizens, your dwarves and friendlies can stroll through this hallway at their convenience, admiring the art and so on, while any (non-TRAPAVOID, that's an important caveat) enemies will be stuck lurching back and forth over the weapon traps and not being able to leave. Can you tell I'm excited about this? Thanks to Fenwah for this trap, which is James-Bond-level epic as far as I can tell.