Editing v0.31:Trap

{{quality|Masterwork|21:10, 26 April 2011 (UTC)}}{{av}}


'''Traps''' are a comparatively quick and easy method for defending a fortress. Unlike [[soldier]]s, they're always on duty, and, once set up, need less management. On the other hand, they are immobile and can only lie in wait for foes to walk over them. To build a trap, go to the {{k|b}}uild->{{k|T}}raps/Levers menu. You'll generally need one [[mechanism]], a dwarf with the [[mechanic]] labor designated (ranks in this [[skill]] reduce the time to place a trap), and at least one other component depending on the type of trap - a stone, a cage, or one or more weapons. They can be built indoors or outdoors, and require a level ground square with no other constructions in them.

Stone-fall, weapon and cage traps will be triggered by most hostile entities entering their tile, with the possible exception of [[thief|thieves]], flying creatures and other occasional nasty surprises.  Any unconscious creature will trigger traps, including your own dwarves.

Note that only dwarves with the mechanic labor enabled will reload traps (cage, stone or weapon). In combat situations, [[mechanic]]s have a nasty habit of wanting to reload (or clean) traps when they are triggered, regardless of who or what might be out there as well. [[Forbid]]ding traps after they are built will keep [[Main:Urist|Urist McSuicide]] from deciding to reload a trap in the middle of a [[siege]]. Just remember to unforbid them when things calm down, so the traps are all ready for next time. Note that forbidding a trap after it has been triggered doesn't help, as the job to refill the trap has already been issued in that case, so a Mechanic will carry a stone out to the trap anyway. Alternatively, simply order your dwarves to stay within a safe [[burrow]] until any threats have been dealt with.  If a cage trap has captured something while forbidden and left alone for an extended period of time (nearly a year or longer) the caged individual escapes and and you will get the announcement "Something has emptied a cage!" Once put into a stockpile or claimed this will prevent the captured individual from escaping.

It is possible to determine the state of a trap (loaded/unloaded) and the components it contains using the {{K|t}} query.
Deconstructing a trap leaves the components used in its creation on the ground around the tile.  Traps destroyed by hostile action may return damaged objects.

==Stone-fall Trap==
The simplest trap to construct, a stone-fall trap is essentially a [[stone]] suspended up in the air which is dropped on intruders when the trap is triggered. These are a popular defensive measure early on, as the components needed are readily available as soon as you start mining. A single stone trap will usually '''not''' severely wound or kill most animals and enemies, to the extent that this may be a bug. After being used they need to be reloaded with another stone by any [[dwarf]] with [[mechanic]] [[skill]] enabled, a task which your dwarves will see to automatically. The dwarf will generally not use the stone that just dropped, but a new one (would you want to put your hands on that gory mess?). Being that stonefall traps do <em>not</em> alert you of ambushes when triggered by hidden invaders{{verify}}, this can frequently lead your mechanics into peril.  The weight of the stone used in the trap affects the amount of damage the trap does, but it's quite difficult to get your dwarves to use heavier stones, like galena, when loading the traps.

:*Shortcut {{k|b}} {{k|T}} {{k|s}}
:*Components used: [[mechanism]] and an ordinary [[stone]]

==Weapon Trap==
Weapon traps are similar in nature to stone-fall traps, and are triggered when any hostile creature stands on the trap. They contain between one and ten weapons, and tend to be much more reliable for outright killing or critically injuring invading creatures. Before you write off stone-fall traps as worse versions of weapon traps, note that weapon traps require you to have previously made [[weapon]]s, making them more of an option somewhat later in the game. Any weapon can be used, including human weapons, training weapons, bows, traded weapons and weapons recovered from dead goblins. Think of it as fair retribution when goblins are sliced to pieces by their own axes!

You can also use the corkscrews that are normally used in [[screw pump]]s, or menacing spikes that are normally used in spike traps, or any of three specialist trap only weapons:

[[Metalsmith's forge]]
*menacing <metal> spike
*large, serrated <metal> disc
*spiked <metal> ball
*enormous <metal> corkscrew
*giant <metal> axe blade

[[Carpenter's workshop]]
*menacing <wooden> spike
*spiked <wooden> ball
*enormous <wooden> corkscrew

[[Glass furnace]]
*menacing <glass> spike
*large, serrated <glass> disc
*spiked <glass> ball
*enormous <glass> corkscrew
*giant <glass> axe blade

Don't know which to make? -> '''Detailed [[Trap component]] information'''

These weapons have all the material property advantages and disadvantages that normal weapons have. It should be noted that the trap weapons are larger than normal dwarf weapons, meaning they should be more effective than normal weapons made of equivalent materials. When triggered, this trap will "attack" the creature with all the weapons available to it, normally doing massive damage.

Weapon traps do not cause slightly suicidal mechanics to reset them after each triggering but instead reset automatically after an unknown period of time. However, there is a 50% chance that the victim will get stuck in the mechanism and cause the trap to jam (use {{k|t}} to check the trap), requiring a dwarf to remove the body. When the trap jams, the mechanic will automatically attempt to clean it, so forbidding the body (or forbidding the trap's mechanism in advance) may be necessary to save him from the victim's friends.

When placing the trap you will be asked for a type of mechanism as normal, then asked to select weapons to use. The quality of your chosen mechanism matters[http://www.bay12games.com/forum/index.php?topic=14461.msg131214#msg131214]. At this point you will get a list of all stockpiled weapons in your fortress. {{k|+}}{{k|-}} will select different weapons and pressing "Enter/Return" adds 1 of the selected weapon to the trap; you can e{{k|x}}pand the selection to choose more carefully. Up to 10 weapons can be put in each trap and all weapons in the trap will attack at once when it is triggered (10 large serrated disks normally results in the unfortunate triggering creature leaving with fewer limbs than it came in with). When happy with your weapon selection press {{k|d}} to set the trap.

The triggering creature will defend from the trap's attacks just like from a dwarf's, by jumping away, dodging and blocking. This can be used in your favour if the trapped tile happens to be surrounded by pits.

:*Shortcut {{k|b}} {{k|T}} {{k|w}}
:*Components used: [[mechanism]] and 1 to 10 weapons.

==Cage Trap==
Cage traps are different to the other trap types in that they do not directly kill or injure invaders. Instead, they capture the unfortunate creature that triggers them in a [[cage]]. Despite the unfortunate lack of violence, this is still very effective as it completely neutralizes the target so that it can be dealt with later. After a creature is captured, it's stored in an animal [[stockpile]] if the current standing order is set ({{K|o}}-{{K|a}}). The trap will then be reset by hauling an empty cage to the trap's location. This is done ''automatically'', as in, during a siege, by any dwarf with the [[Mechanic]]s labor enabled. Cage traps will also alert you to ambushes when triggered by hidden invaders, making them a useful forward defense mechanism.

'''Most''' captured creatures do not require any nourishment and will survive being in a cage indefinitely; in fact, even submersion in water or magma appears to have no effect on caged creatures.  It is possible for dwarves to bring [[water]] to cages, but this will only occur if you have someone friendly also locked in the cage - like a dwarf child snatched by a goblin. See below for how to remove things from a cage.

'''Cage traps will not capture every creature in the game''', so you ''will'' need alternative defenses - [[titan]]s and [[forgotten beast]]s (as well as certain other types of creatures) are immune to traps entirely and will waltz right past all of your carefully placed cages unless the cage has a giant cave spider web on it.  A webbed cage trap '''will''' capture absolutely '''anything''' in the current version.

Cage traps are also useful for catching wild animals. This can be done by simply placing traps in areas where wild animals roam (this does '''not''' require a dwarf with the [[trapping]] labor enabled). The captured animals can be tamed (and sometimes trained into war animals!) at the [[kennel|kennels]]. See [[dungeon master]] for current bugs related to training animals.

In the process of taming a wild animal, there is a chance that seeds will be left in the cage. Dwarves ''only'' load empty traps.  One way to remove the seeds and make the cage usable again is to {{K|d}}ump them. First loo{{K|k}} at the cage in your Animal [[stockpile]], then highlight the seed and press {{K|Enter}} to look at the seed, then press {{K|d}} to dump the seed.

Merchants, especially Elfs, will bring cages that on the trading screen look empty. However, if you {{k|v}}iew the item, you will often see that it contains a tame vermin like a frog or squirrel.

:*Shortcut {{k|b}} {{k|T}} {{k|c}}
:*Components used: [[mechanism]] and a [[cage]].
:*If the trap is a Dark Green, then it does not have a cage in it.
:*If the trap is a Light Green, then it does have a cage in it.
:*Note that cage material has no effect (beyond weight for hauling, value of finished trap, and the fact that [[elf]] merchants will get pissy if the cage is wooden).  A glass terrarium is just as strong as a steel cage. 

To release a creature from a cage, build the cage ({{k|b}} {{k|j}}) and use {{k|q}} to unassign it.  You can also simply assign the creature to a pasture or pit. To release a hostile creature (or wild animal) safely from a cage, build the cage and link the cage to a [[lever]] that can be remotely triggered. If you have many cages you need to empty out quickly see [[Mass pitting]].  Cages have no current limit to the amount of beasts you can put in them, so you can build one cage and assign all the beasts to that cage.  Typical caveats of dealing with wild/hostile animals apply.

==Upright Spear/Spike==

A variation of the weapon trap, the Upright Spear/Spike itself requires no mechanisms, and can be fitted with up to 10 [[Weapon|spears]] or [[Trap component|spikes]].  However, it requires an external trigger to actually impale things.  Either a [[pressure plate]] or a [[lever]] must be connected to this trap for it to be operated.  An advantage of this trap is it doesn't require a mechanic to set it up - just to link it to a trigger.  

An often overlooked ability of an upright spike trap is that it also inflicts damage on a creature that falls onto it while it is deployed.  And since they are built in the deployed state they can be quickly built to make a pit trap more lethal, without the need for extra mechanisms.  However, you will still need the mechanisms that cause your victims to fall onto the spike from above in the first place, and the pit must be more than 1 z level deep for the spikes to cause damage.

:*Shortcut {{k|b}} {{k|T}} {{k|S}}
:*Components used:  between 1 and 10 spears or spikes.

==Mechanism Quality==

All of the above traps other than Upright Spear use mechanisms in their construction.  The quality of the mechanism used impacts weapon traps beyond their value however, in weapons traps the mechanism quality seems to act similarly to weapon skill in an entity and will play a part in determining whether a strike lands.  Code analysis suggests that mechanism quality also impacts the effectiveness of stone fall traps, though it has no effect on cage traps.

==Other Traps==
You can create even more elaborate traps with imaginative use of pits, [[pressure plate]]s, [[lever]]s, [[grate]]s, [[support]]s, [[water]], and/or [[magma]], creating sacrificial altars (blood for the Blood God!) and whatever else you can think of.  Watching those goblins try to find a way out of your drowning chamber as it begins to fill is really quite satisfying.  These are best made in a large, repeatable mass killing way. If you make a trap that kills 10 or so goblins that only works once and you have to rebuild it, wasting time you don't have during a [[siege]], then you're not trying hard enough.

==See Also==
*[[Trap design]]
*[[Mass pitting]]
{{buildings}}
{{Category|Traps}}