Mass pitting

Warning!

There have been multiple reports of hostile creatures escaping confinement while pitting. In previous versions, only "thief" type creatures, flyers, or large creatures like titans would escape using this system. The 0.40 behavior is still being investigated. If in doubt, build the cage manually or have sufficient military hanging around the top stockpile area.

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v50.14 · v0.47.05 This article is about the current version of DF. Note that some content may still need to be updated. More Info · V

Mass pitting refers to pitting many caged creatures at one time without having to build each cage and link it to a lever. This allows you to recycle many cages quickly, freeing them up for reuse in cage traps in minimal time.

Mass Pitting System

Also called the Mass Cage Recycling System.

Here's a simple design that keeps you from having to build cages before releasing hostile creatures from them. This is safe for most hostiles, but see warnings below.

Building

1. Dig out a room and another room of at least the same size directly below it.
2. In the upper room channel out 6 openings into the lower room which are spaced exactly 2 tiles away from each other.
3. Build floor hatches and place them over all of the openings.
4. Mark each hatch forbidden and tightly closed (In experiments this has shown to stop normal creatures in 40.x from escaping)
5. Place one big animal stockpile over the room such that every tile in the stockpile is adjacent (orthogonally and diagonally) to one of the hatches. Disable empty cages on the stockpile.
6. Create one large pit zone that covers all of the openings such that all of them are part of the same pit zone. This is critical to prevent hostiles from being led around and spooking your civilians.
7. Disable all other animal stockpiles except for one empty-cage-only stockpile somewhere.
8. See below for some suggestions on what to drop your invaders into.

The top room should end up looking like this:

=	=	=	=	=	=	=	=	=
=	¢	=	=	¢	=	=	¢	=
=	=	=	=	=	=	=	=	=
=	=	=	=	=	=	=	=	=
=	¢	=	=	¢	=	=	¢	=
=	=	=	=	=	=	=	=	=

= is the stockpile

¢ is a hatch cover

The bottom room can look like whatever you want as long as all of the openings you channeled out lead into it from the ceiling.

Obviously you can scale up the top part with more or fewer hatch openings to get larger or smaller stockpile areas, but with six hatches you can empty out 48 cages very quickly, without spooking dwarves, which is enough for many people.

Variations of this design exist, but they all use the same basic principle, that is, all hostiles must be no more than one tile away from a suitable pit. Dwarves must not be ordered to haul the hostile across any distance or else they will become startled and release the dangerous creature.

Use

Before pitting your captives, you may wish to disarm them -- depending on what you've built for them to fall into.

Now, wait for the stockpile above to fill and assign creatures to the pit all in one shot. Being pitted through the hatches will keep dwarves from being spooked by hostile creatures below and with all cages directly adjacent to pits creatures can be dumped in instantly without having to be led around.

A mass of dwarves will pile into the room, pit the creatures at the about same time, and haul the empty cages off to your empty cage stockpile. The poor pathetic creatures they pitted will then be left to the mercy of whatever is at the bottom of the pits.

The Pit

After your dwarves have dumped out the cages the inhabitants will be dropped into the room below. Here you can find some suggestions on its construction:

Drowning chamber

Fill up the room below with water and watch as the invaders drown. Requires only some buckets and a water source. May be difficult or troublesome to recover anything dropped into the waters below. Consider a filling and draining method using floodgates bordered by fortifications. Ensure that the hatches over the openings are permamently set to forbidden, otherwise things can and will swim back into the room above resulting in fun. Dwarves will not have an issue dumping things through the forbidden hatches.

EX

This is a possible drowning pit where water flows through a tunnel to the right and drains out the left. Be sure they are hooked to separate levers, and remember the fortification keeps dead things from flowing out, not live things from swimming out. A door along the bottom of this design allows dwarfs in to loot the spoils, and or clear out any unwanted buildup of bodies ETC.

        ░░░░░░░░░░░░
        ░          ░
  ░░░░░░░          ░░░░░░░░
       FX          X       
  ░░░░░░░          ░░░░░░░░
        ░          ░
        ░░░░░X░░░░░░
            ░ ░

X=Floodgate F=Fortification

Lava Pool

Alternatively you can fill the room with magma and watch as the hostiles are instantly incinerated! Requires an aqueduct and/or magma safe materials.

Weapon Trap Hallway

On the level below the pit opening place weapon traps in a 1 square wide hallway. The dumped creature will run for the exit through the weapon traps until dead. You can put a cage trap at the end just in case the creature successfully escapes with his life.

Level 1

            ░░░░░
            ░nnn░
      ░░░░░░░npn░
           cDnnn░
      ░░░░░░░░░░░
       

Level -1

            ░░░░░░░
            ░TTTT ░
            ░T░░░ ░
            ░T░T░ ░   <-- align p  n Lvl 1 with center T  n this level.
            ░TTT░ ░
░░░░░░░░░░░░░░░░░ ░
        cD        ░
░░░░░░░░░░░░░░░░░░░

p=Pit opening D=Door c=cage trap T=weapon trap n=cage staging area

Empty Room

Leaving the room down below empty has its benefits. When your melee military has nothing better to do then beating unarmed goblins will train fighting skills quickly. Be sure to haul off corpses before miasma begins forming. If you are planning to kill your goblins by pitting them into an empty room, remember that height alone is not a reliable method of enemy disposal. Even if your empty room is 10-15 z-levels below, you will still get a high number of survivors and some will escape unharmed - especially when falling on top of enemies pitted previously.

Goblin Training

Through the use of spike traps, goblins can be trained in the same manner as a standard danger room. Uses for these master goblin fighters include extended target practice, an expendable military addition to be dumped on particularly nasty forgotten beasts, or a last resort contingency plan against non-goblin invader-induced fun.

Fortifications

Marksdwarf training room

By lining the pit room with fortifications you are able to safely train your marksdwarves. This provides a feasible and quick alternative to the slow process of using archery targets. By ordering your military to use bone bolts and leaving your hostiles fully armored even a small group of goblins will live to be used as target practice for months. Miasma produced during this time may give dwarves unhappy thoughts. To avoid this stagger fortifications with solid walls in such a way that diagonal gaps are between you and the rot.

Remember that goblin marksmen will still be able to shoot through fortifications if they are armed sufficiently. To avoid this exclude or disarm them.

Also remember that you must keep civilians out of sight of the fortifications. Despite blocking the pathing of the hostiles, it does not prevent civilians from canceling jobs when they see the baddies through your fortifications.

Long Term Maintenance

In order to protect frame rate, spread of miasma if you are using this for melee training, gather any remaining loot that was not removed before pitting the creatures, or simply a desire for fortress cleanliness, you can make a bridge as part or all of one wall to the pit. When retracted it acts as a wall and removes any danger of escaping prisoners, but when all are dead or sufficient military is waiting, you may lower this to retrieve any bodies or valuables. If you do not like having a pit unavailable during this time, you may consider building a second to alternate uses between which one is being filled and which one is being emptied. Another alternative is to build a raising (instead of a retracting) bridge and use it to atomize all of the miasma producing corpses instead of hauling them topside.

Alternative Minecart Design

It is possible to automate a mass pitting system with minecarts. Minecart "shotgunning" is when a minecart traveling at significant speed encounters an obstacle and "launches" its contents. Cages which were in the minecart, and which encounter an obstacle while traveling at significant speed will similarly "shotgun" their contents, launching their inhabitants. This can empty an entire minecart full of cages simultaneously, without fear of escape. Note, however, that flying creatures may still be problematic.