Editing 40d:Cave-in

'''Cave-ins''' occur whenever any 7x7 (or larger) area is fully excavated. Therefore, you must exercise caution when [[mining]] large contiguous spaces. If you have mined out too large a space, the game will sometimes provide a warning in the form of "a deep rumbling from the cavern."

Objects and occupants caught in a cave-in can be damaged or destroyed. Cave-ins will scatter about a dozen partly-mined [[rock]] tiles across a wide area along with a cloud of dust and debris that can knock out nearby supports, triggering a potential chain reaction. A cave-in that occurs over the [[magma]] river can also produce [[magma mist]]. The rock left behind will always be gray stone, not light or dark stone, [[ore]], or [[gems]]. This rock can be mined out again (sometimes leaving behind new stones), but at least one tile should be left unmined as a pillar to prevent another cave-in.

== Avoiding cave-ins ==

To avoid cave-ins, you must have a minimum of one [[support]] (or unmined wall, referred to as a '''pillar''') somewhere in a fully-excavated 7x7 region. 

'''The general rule to remember for all situations is, 7x7 = ''not safe'', 7x7 - 1 = ''safe''.''' 

For instance, the following 7x7 room can be safely created because it has a "notch" in it. This pillar could be located anywhere within the 7x7 area to prevent a cave-in:

<div style="font-family: monospace; white-space: pre; line-height: 126.5%"><nowiki>
▒▒▒▒▒▒▒▒▒
▒▒......▒
▒.......▒
▒.......▒
▒.......▒ ▒ = Support or wall
▒.......▒
▒.......▒
▒.......▒
▒▒▒▒▒▒▒▒▒
</nowiki></div>

For maximal use of space, supports or pillars should be put at each corner of each 8x8 region:

<div style="font-family: monospace; white-space: pre; line-height: 126.5%"><nowiki>
▒......▒......▒......▒
......................
......................
......................
......................
......................
......................
▒......▒......▒......▒
......................
......................
...................... ▒ = Support or unmined space
......................
......................
......................
▒......▒......▒......▒
</nowiki></div>

An enclosed 13x13 space could be built like this:

<div style="font-family: monospace; white-space: pre; line-height: 126.5%"><nowiki>
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
▒.............▒
▒.............▒
▒.............▒
▒.............▒
▒.............▒ ▒ = Support or wall
▒.............▒
▒......▒......▒
▒..............
▒..............
▒..............
▒..............
▒..............
▒..............
▒▒▒▒......▒▒▒▒▒
</nowiki></div>

The above example includes two large passageways leading into the room. As long as neither passageway is widened beyond 6 squares, no fully-cleared 7x7 regions will exist, and the structure will remain safe.

Rooms which are 6 squares across or less can be indefinitely long or wide without needing supports:

<div style="font-family: monospace; white-space: pre; line-height: 126.5%"><nowiki>
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
....................................
....................................
....................................
....................................
....................................
....................................
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
</nowiki></div>

They are often called "hallways."

Doorways or other passageways can be set into this hallway as long as the opening is never more than 6 squares across:

<div style="font-family: monospace; white-space: pre; line-height: 126.5%"><nowiki>
▒▒▒▒▒▒▒......▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
▒▒▒▒▒▒▒......▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
▒▒▒▒▒▒▒......▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
▒▒▒▒▒▒▓......▓▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
....................................
....................................
....................................
....................................
....................................
....................................
▒▒▓......▓......▓..▒▒▒▒▒▒▓......▓▒▒▒
▒▒▒.............▒.....▒▒▒▒▒▒▒▒▒▒▒▒▒▒
▒▒▒.............▒.....▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ▓ = Mandatory rock wall/support
▒▒▒...................▒▒▒▒▒▒▒▒▒▒▒▒▒▒
▒▒▒.............▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
▒▒▒.............▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
▒▒▒.............▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
▒▒▒......▓......▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
</nowiki></div>

If any of the rock marked <tt>▓</tt> is cleared, that will create an uninterrupted 7x7 region, which will collapse.

[[River]], [[chasm]], and [[magma]] tiles are considered walls by the game, so you can safely excavate up to 6 squares deep along each of their banks.

== Creating cave-ins ==

Cave-ins can be a good thing when used right. For example, they could [[User:Savok/Chemical_Warfare|knock out a multitude of invaders]], block off a permaflood, or remove a channel.

There are two ways to make cave-ins. The first and simplest is by simply mining out a 7x7 uninterrupted region. A cave-in trigger will periodically happen. When it happens, all 7x7 regions will collapse.

You can also place a support in the 7x7 region and hook the support up to a lever. When you pull the lever, the support will collapse and a cave-in will happen immediately.

In an extremely long term game, cave-ins can be used to replenish depleted stone supplies.

[[Category:Rooms]]
@@ Line 1: / Line 1: @@
-{{quality|Exceptional|15:54, 29 April 2011 (UTC)}}{{av}}
+'''Cave-ins''' occur whenever any 7x7 (or larger) area is fully excavated. Therefore, you must exercise caution when [[mining]] large contiguous spaces. If you have mined out too large a space, the game will sometimes provide a warning in the form of "a deep rumbling from the cavern."
-:''A section of the cavern has collapsed!''
-A '''cave-in''' is when walls, floors, and objects plummet downwards to lower [[Z-axis|Z-levels]] under the influence of [[gravity]]. A cave-in will occur if constructions or ground tiles are detached from all supporting tiles (bridges and the like do not support constructions). Since it is only a placeholder, the system is highly unrealistic&mdash;you can hold up a giant megafortress by a slender pillar of soap. [[Main:Toady One|Toady One]] has stated he intends to implement more realistic cave-ins in future versions.
+Objects and occupants caught in a cave-in can be damaged or destroyed. Cave-ins will scatter about a dozen partly-mined [[rock]] tiles across a wide area along with a cloud of dust and debris that can knock out nearby supports, triggering a potential chain reaction. A cave-in that occurs over the [[magma]] river can also produce [[magma mist]]. The rock left behind will always be gray stone, not light or dark stone, [[ore]], or [[gems]]. This rock can be mined out again (sometimes leaving behind new stones), but at least one tile should be left unmined as a pillar to prevent another cave-in.
-Cave-ins can be disabled through the [[Main:Technical tricks|init]] file, by changing [CAVEINS:YES] to [CAVEINS:NO].
+== Avoiding cave-ins ==
-== How cave-ins work ==
-Any ''disconnected'' [[construction]] or section of [[rock]] or [[soil]] will cave in. The game checks for connections along the X, Y, and Z axes (that's left/right, up/down, and above/below). Any construction, even [[Stair]]s (natural or constructed), and [[support]]s (naturally) provide support/connections. [[Stairs|Upstairs]] will provide support for the z-level above even if there is no downstairs above, acting as an invisible floor. '''Diagonal connections and [[bridge]]s do not provide support.'''
-== Results of a cave-in ==
+To avoid cave-ins, you must have a minimum of one [[support]] (or unmined wall, referred to as a '''pillar''') somewhere in a fully-excavated 7x7 region.
-* Any [[creature]] caught under the falling material is crushed and killed.
+'''The general rule to remember for all situations is, 7x7 = ''not safe'', 7x7 - 1 = ''safe''.'''
-* Any item caught under falling natural walls is destroyed completely. Natural floors and constructed walls and floors have a small chance of destroying items.
-* Anything standing on the area that caves in falls and may be wounded. The fall victim has a chance of being unable to walk away, somewhat proportional to the distance fallen but not set in stone. No pun intended.
-* A large amount of dust is generated. Any creature caught by the dust from the collapse is knocked [[unconscious]] and thrown a few tiles, which may cause them to fall off a narrow bridge fifty z-levels above the ground.
-* All [[building]]s and non-wall [[construction]]s under the falling area are destroyed. Buildings above the cave-in will deconstruct if they are no longer supported.
-* Natural terrain will remain intact during the cave-in; the only effect is they are revealed.
-* Constructions will deconstruct when they collide with solid terrain.
-* Any terrain crashes through multiple [[floor]]s, and stops only upon reaching solid ground or a constructed wall, where natural terrain piles up and constructions deconstruct.
-* Mined stairs and [[ramp]]s will settle like unmined rock; Stairs down that fall onto previously empty [[floor]]s will reveal the level below. If there's rock or floor above them, it'll cover the stairs.
-* Anything falling into a fluid sinks to the bottom. Therefore, it is not a good idea to punch a skylight into your meeting area if you forgot that e.g. your [[gem]] pile was directly below and you had a [[magma]] tube three Z levels afterward... you get the idea.
-* Any water or magma displaced by falling natural walls is not destroyed, but teleported upwards(!) to directly on top of the fallen walls.
-== Avoiding cave-ins ==
+For instance, the following 7x7 room can be safely created because it has a "notch" in it. This pillar could be located anywhere within the 7x7 area to prevent a cave-in:
-Do not make unconnected sections of rock.
+<div style="font-family: monospace; white-space: pre; line-height: 126.5%"><nowiki>
+▒▒▒▒▒▒▒▒▒
+▒▒......▒
+▒.......▒
+▒.......▒
+▒.......▒ ▒ = Support or wall
+▒.......▒
+▒.......▒
+▒.......▒
+▒▒▒▒▒▒▒▒▒
+</nowiki></div>
-Actually, you're quite unlikely to cause cave-ins unless you are actively trying to cause them. In which case, you'd be wondering how to avoid cave-ins that ''cause damage'' to your folks. That's simple: Add a [[support]] under the stone mass, and link it to a distant [[lever]]. When you're done, hide everyone, pull the lever and watch the fireworks.
+For maximal use of space, supports or pillars should be put at each corner of each 8x8 region:
-One of the more common accidental cave-ins results when you're taking out the floor in a checker-pattern (dwarves [[channel]]ing may sometimes tend to make this mistake) and the area below isn't supported, resulting in a situation like the diagram below:
+<div style="font-family: monospace; white-space: pre; line-height: 126.5%"><nowiki>
+▒......▒......▒......▒
+......................
+......................
+......................
+......................
+......................
+......................
+▒......▒......▒......▒
+......................
+......................
+...................... ▒ = Support or unmined space
+......................
+......................
+......................
+▒......▒......▒......▒
+</nowiki></div>
-<pre>
+An enclosed 13x13 space could be built like this:
- Floor -1
- ▒▒▒▒▒▒
- ▒    ▒
- ▒ X +▒ <-- The X is a floor tile. It's not attached, so it will fall down.
- ▒  +>▒
- ▒    ▒
- ▒▒▒▒▒▒
- Floor -2
- ▒▒▒▒▒▒
- ▒....▒
- ▒...▒▒ <-- Causing this area to receive a cave-in flow and knocking out any dwarves in its reach.
- ▒...<▒
- ▒....▒
- ▒▒▒▒▒▒
-</pre>
-Another thing to watch out for is if you want to dig away a hill above ground, to make room for your fancy overground fort. You may dig away the hill on one level, and then have a huge platform of "floor" on the z-level above that falls on your [[miner]] if they get disconnected from the ground. Easy thing to miss the first time you do it.
+<div style="font-family: monospace; white-space: pre; line-height: 126.5%"><nowiki>
+▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
+▒.............▒
+▒.............▒
+▒.............▒
+▒.............▒
+▒.............▒ ▒ = Support or wall
+▒.............▒
+▒......▒......▒
+▒..............
+▒..............
+▒..............
+▒..............
+▒..............
+▒..............
+▒▒▒▒......▒▒▒▒▒
+</nowiki></div>
-The solution here is to dig ramps instead, since these take away both the [[soil]] on the level you are digging on and the floor on the level above. This is not foolproof, however, as [[tree]]s will prevent the floor it's on from being removed, resulting a free-hanging floor when you carve the ramp around it. In addition, ramps do not provide support for other tiles on the higher z-level; depending upon the order they are constructed, cave-ins may still occur.
+The above example includes two large passageways leading into the room. As long as neither passageway is widened beyond 6 squares, no fully-cleared 7x7 regions will exist, and the structure will remain safe.
-== Using cave-ins ==
+Rooms which are 6 squares across or less can be indefinitely long or wide without needing supports:
-Intentional cave-ins serve several purposes:
-* '''[[Dam]]s'''
-*: Dropping a section of natural rock above an [[underground river]] can provide a way to dam the river. Similarly, causing a cave-in is probably the easiest way to be able to dig beneath an [[aquifer]] you can't dig around. This only works with natural rock; [[constructions]] will revert to their components, and not block the river at all.
-* '''Death'''
-*: Since a cave-in kills all [[creatures]] instantly, it can provide a convenient or amusing way to off a group of creatures.
-* '''Removal of floor tiles'''
-*: Causing a cave-in will destroy non-reinforced (no wall or support underneath) floor tiles directly underneath the falling terrain - this is a good way to e.g. hollow out a large area. All that's left to do is a little bit of cleanup on the edges, but look at all the channeling you save yourself!
-* '''Destroying items'''
-*: Elven siege left behind a bunch of worthless wooden weapons? Got some fire imp fat in your butcher's shop? Need an amusing way to off your stone? Smash it with a cave-in and you'll never see it again.
-* '''Breaking through multiple aquifer levels'''
-*: Showcase with two levels: [[User:Rhenaya/HowtoDualAquifer]]
-* '''Trapping [TRAPAVOID] creatures'''
-*: Since the dust from a cave in knocks out creatures, and any unconscious creature triggers a trap (This includes your dwarves and other friendly creatures), combine a cave in with cage traps for the capture.
-=== Caving-in the toplevel/terrain from inside ===
+<div style="font-family: monospace; white-space: pre; line-height: 126.5%"><nowiki>
+▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
+....................................
+....................................
+....................................
+....................................
+....................................
+....................................
+▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
+</nowiki></div>
-You can cause terrain above you to cave in without going outside by first mining up stairs below the "borderline" you want to channel, and then channeling the tiles above them.
+They are often called "hallways."
-The tiles above the up stairs can be mined from below while standing on the stair, so you don't have to go outside. Ramps would also work for that alone, but the ramps would allow enemies to enter, whereas the up-stairs alone do not allow passage to above as there is no corresponding down-stair above them.
-==== Step 1: Preparation, up-stairs ====
+Doorways or other passageways can be set into this hallway as long as the opening is never more than 6 squares across:
-[[Z-axis|Z-level]] -1: The level below the target, part of your tunnels.
+<div style="font-family: monospace; white-space: pre; line-height: 126.5%"><nowiki>
- ▒▒▒▒▒▒▒
+▒▒▒▒▒▒▒......▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
- ▒<<<<<▒
+▒▒▒▒▒▒▒......▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
- ▒<...<▒
+▒▒▒▒▒▒▒......▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
- ▒<.S.<▒
+▒▒▒▒▒▒▓......▓▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
- ▒<...<▒
+....................................
- ▒<<<<<▒
+....................................
- ▒▒▒▒▒▒▒
+....................................
-* < = up-stairs
+....................................
-* S = support
+....................................
-Dig or build an [[orthogonal]]ly-connected ring of [[stairs]] up, and place a [[support]] inside it.
+....................................
+▒▒▓......▓......▓..▒▒▒▒▒▒▓......▓▒▒▒
+▒▒▒.............▒.....▒▒▒▒▒▒▒▒▒▒▒▒▒▒
+▒▒▒.............▒.....▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ▓ = Mandatory rock wall/support
+▒▒▒...................▒▒▒▒▒▒▒▒▒▒▒▒▒▒
+▒▒▒.............▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
+▒▒▒.............▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
+▒▒▒.............▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
+▒▒▒......▓......▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
+</nowiki></div>
-==== Step 2: Channeling ====
+If any of the rock marked <tt>▓</tt> is cleared, that will create an uninterrupted 7x7 region, which will collapse.
-[[Z-axis|Z-level]] 0: Your enemies, trees, etc. are on this level, and none of your dwarves needs to go here.
+[[River]], [[chasm]], and [[magma]] tiles are considered walls by the game, so you can safely excavate up to 6 squares deep along each of their banks.
- .......
- .CCCCC.
- .C...C.
- .C...C.
- .C...C.
- .CCCCC.
- .......
-* C = Channel
-[[Designate]] one [[channel]] above each stair from the previous step.
-* Dwarves are able to dig the channels by standing below on the stairs.
-* Enemies are not able to enter without down-stairs connected to the up-stairs.
-==== Step 3: Keep your dwarves safe and pull the lever ====
+== Creating cave-ins ==
-Note: Your dwarves will not dig the channels if "dwarves stay indoors" is active, but you can lock them in using drawbridges to prevent them from going outside.
+Cave-ins can be a good thing when used right. For example, they could [[User:Savok/Chemical_Warfare|knock out a multitude of invaders]], block off a permaflood, or remove a channel.
-Beware, enemies with ranged weapons are able to shoot down the channels at your dwarves below, but they should be safe from melee fighters.
+There are two ways to make cave-ins. The first and simplest is by simply mining out a 7x7 uninterrupted region. A cave-in trigger will periodically happen. When it happens, all 7x7 regions will collapse.
-Want an underground forest but no underground river on the map? No problem, just drop the above-ground-forest a few z-levels and build a floor above it.
+You can also place a support in the 7x7 region and hook the support up to a lever. When you pull the lever, the support will collapse and a cave-in will happen immediately.
-{{Mining FAQ}}
+In an extremely long term game, cave-ins can be used to replenish depleted stone supplies.
-{{Category|Guides}}
+[[Category:Rooms]]
-{{Category|Physics}}