Editing v0.34:Fortification

{{Quality|Exceptional|00:42, 8 May 2013 (UTC)}}
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'''Fortification''' is a construction that allows the passage of [[ammunition|projectiles]] [in and out] and liquids, [[mist]], [[steam]], [[web|webs]], [[fire]], [[miasma]] and [[smoke]], but not [[creature]]s, making them an important part in a fortress's [[defense guide|defense]]. An archer must have a skill level of accomplished or higher to shoot through fortifications from a distance; otherwise they must stand directly next to the fortification to shoot through it. 

Fortifications allow liquids to pass through in any direction except vertically -- they implicitly include a floor (even when constructed over empty space) so liquids will not fall out their bottom.

Fortifications ''constructed'' as such are open on top (until a floor or something else is built one Z-level above). Fortifications ''carved'' out of a wall (whether natural and constructed) retain most properties of the wall, including a non-construction floor one level above.

== Building Fortifications ==

Fortifications can be built one of two ways. Firstly, they can be carved from [[construction|constructed]] walls or [[smoothing|smooth]]ed natural walls by pressing {{K|d}}esignation and then C{{K|a}}rve Fortifications. The second way is through the [[construction]] [[menu]]: First press {{K|b}}, then {{K|C}} followed by {{K|F}}ortifications. As with most [[building]]s, this will require one unit of [[wood]], [[stone]], [[metal]], or [[glass]]. Note that constructed fortifications do ''not'' have walkable [[floor]]s above them, while carved fortifications do.

Carved fortifications must be carved by a dwarf with the [[Stone detailing]] [[labor]] enabled. Constructed fortifications must be built by a dwarf with a corresponding labor to the material used.

== Uses ==

[[Flying]] creatures can of course fly over fortifications (but not through). If there is open space above your defense positions, you can either carve them in the first place or build [[floor]] tiles on the Z-level above as a roof against fliers. This is generally sound advice as dwarves don't like rain anyway and strange accidents can cause the weirdest things to fall from above. Note that fliers can diagonally bypass a fortification if the tile above the fortification doesn't have a floor. 

Enemy archers may also fire back through your fortifications. Enemies that stand directly next to your fortifications can fire inward, therefor it's recommended to build a moat around your fortifications, or elevate them from the ground level. Enemy '''elite''' bowmen and crossbowmen have sufficient skill to fire through your fortifications from any distance within their range and they will shoot right through every time and (likely) decimate your forces. Elite bowman can be defended against without compromising the usefulness of a fortification network by constructing a thin 1-tile wide raising [[bridge]] just outside the fortification. Attach each bridge to a [[lever]] and pull the lever if an elite goblin poses a threat. The blocking bridge will cut off line of sight and prevent bolts from penetrating your defenses.

Melee combat can cause severed body parts of the combatants and their carried items to become stuck inside nearby fortifications. Dwarves cannot directly recover these items, which can cause problems with clutter and especially [[miasma]]. The easiest solution is to destroy and reconstruct the fortification. Same applies to objects falling from above, thus if a fortification is used to e.g. protect a water sink, installing a floor [[grate]] above it may be a good idea: it will catch most stuff that would end up stuck in the fortification. It's not as simple with horizontal movement, but sometimes a line of vertical [[bars]] or [[grate]]s may help - if something gets stuck in them first, at least that place can be made accessible simply by flipping a [[lever]], then closed again just as quickly.

Fortifications combined with [[window]]s can enable dwarves or their animals to watch for stealthy intruders from safety. As [[construction]]s, fortifications are immune to [[building destroyer]]s, yet they allow enemy archers to murder your watch-chickens. Windows will stop arrows, but as [[building]]s they're vulnerable to building destroyers. Combined correctly, the two can provide a see-through barrier that protects your watch-animals against any enemy, with the possible exception of an enemy that breathes [[fire]]. With enough animals on the job, this setup will reveal all [[ambush]]es and many a [[thief]] - note that since this leaves only 1 tile of 3 [[Observer|maximum detection range]] of stealthy units, so it can't be avoided altogether only in 1-tile wide (2 if observed from both sides) corridors. Its major weakness is the problem with body parts getting stuck in the fortifications.

Curiously, a fortification carved into a tile at the very edge of the map will allow water or magma to drain through it and off of the map.

In [[adventurer mode]] you can throw any item (such as bows, arrows, axes, hammers, shields, body armour, severed limbs, corpses, etc.) through a fortification, but you cannot climb through them.


== Bugs ==
* Fully submerged (i.e. 7/7 depth) fortifications will '''not''' block the passage of creatures that swim in water (or magma) - wall [[grate]]s and vertical [[bars]] work, but they are vulnerable to [[building destroyer]]s.{{Bug|3327}}
* A partially-submerged fortification (even with 6/7 depth) completely blocks the passage of creatures, despite the fortification being invisible, however if the water is flowing, it can push creatures through fortifications, even if they are not fully submerged (that is at least true at 2-3/7 depth). {{Bug|5458}}
* Items also can be pushed or dropped into a fortification, and remain inaccessible until it's removed. {{Bug|2163}}
* Additionally, there are other conditions that may allow a creature to pass through a fortification, such as being thrown by a wrestler, tossed by a bridge, or dropped from above. Should a creature end up in a fortification tile, it can path and move out of the fortification to any adjacent passable tile. If a creature is killed by an attack which knocks it into a fortification, its corpse and equipment will become lodged inside, requiring mining or deconstructing the fortification to remove the items.
** When this happens to a dwarf with baby, the baby gets dropped and then cannot leave the fortification on its own (unless one happens to grow into child while there). Removing the fortification is not possible when a baby is sitting there. {{Bug|2160}}
* Line of sight through fortifications can be wonky. Specifically, marksdwarves often fail to register that there are enemies on the other side unless they (the dwarves) are directly next to the fortification. {{Bug|2697}} Having a single-tile hall behind can help. [[Statue]]s can be used as "soft" impassable tiles for this purpose: dwarves can dodge into one, but won't try to walk into such tile normally.

{{buildings}}