40d:Magma

Magma is red-hot molten rock present in volcanoes (it is called lava after it is erupted), as well as magma pools and magma pipes. It serves as an energy source, powering magma forges, magma glass furnaces and magma smelters. It is extremely dangerous.

Magma sources

Magma occurs in three different features; Magma pools, Magma Pipes, and Volcanoes.

• A Magma Pool is a reservoir of magma that occupies only a few Z-Levels in the mountain, without reaching the surface. Magma Pools can be very small, and may have few suitable locations for buildings that rely on magma. Magma in these pools is limited, and pools will not refill with magma once emptied.

• A Magma Pipe starts at the lowest z-level of the map from a magma (or lava) flow and extend in a pipe shape upwards, sometimes reaching the surface but often not. Magma Pipes gradually refill with magma.

• A Volcano is similar to a magma pipe, but it has the advantage of being a geographical feature that is visible on the location screen. This means that it is a lot easier to find. However, it IS actually possible for a volcano that shows up on the "local" and region screen in the starting location chooser to be entirely underground - Although you could see it in the starting location chooser, it would not be visible from the surface once your dwarves have arrived at the fort's site.

Finding magma

Volcanoes are visible on the "local" screen in the starting location chooser. It is represented as a red ≈ mark (a double tilde) - essentially it looks like red water. Note that red ≈ marks in the "region" screen mean something different entirely (e.g. red sand). If you are using a certain utility, you can also see magma pools and magma pipes on the local screen in the embark menu. After you have embarked for a place that has a volcano, and once your dwarves have arrived at their target destination, you should see a large red pool of lava on your map. If you don't, you should expect your volcano to be somewhere underground. You then have to use exploratory mining to find it. If you can find a large patch of obsidian on the surface that is devoid of boulders, chances are there is a magma vent below, so that would be a good place to start your mining.

While picking a starting location, the easiest place to look for magma is on or near a volcano (a red ^ mark in the "region" screen). There are often volcanic islands (easy to find, since they are the sole land in the middle of oceans), but since sea travel is not yet implemented, trade with other races may not be possible on such islands. Instead, find a volcano on land, and (optionally) start looking for a vent in nearby squares. "Nearby squares" can mean anything from literally on top of the volcano, to adjacent, to quite a long distance away indeed. The placement of magma seems to be related to the distance from volcanoes, but is still essentially random.

Magma vents occur exclusively in world map tiles that are primarily igneous extrusive. That is to say, if you select an entire tile on the embarkation screen and press F1 to highlight the most common terrain, the tile will only have magma if the top stone is dark gray, signifying igneous extrusive rock. Magma does not necessarily form in this geological zone/biome, rather anywhere in the tile. Even if magma is not evident on the surface, it's almost certain to be underground somewhere, though the chances of finding it without reveal.exe are still slim.

Much harder than simply finding a magma vent is finding a magma vent that is also near suitable terrain for building. Depending on your requirements - you may be looking for a source of running water, or a mountain for minerals, or a healthy tree population, a layer of flux for steel production or even all four - suitable building sites can be extremely scarce.

Since volcanoes show up on the region finder, and magma vents do not, you may find it easier to simply check all volcanoes on a map for suitability, and generate a new world if none are suitable, rather than scouring tile after tile for magma vents.

If you're willing to search exhaustively, you might want to consider finding magma vents that are not near volcanoes at all. Very occasionally, magma will be visible in the middle of forests, plains, or other terrain nowhere near a volcano or even mountains. There is no way to spot these on the region map, so you have to review the local maps. This can be done from DF, but since it involves a lot of scrolling and is very tedious, you can try exporting the local map of the world which can be much more quickly searched for the distinctive red ≈ symbol.

You can also occasionally find magma that does not extend all the way to the surface, and therefore is not visible on the local map. These are in fact much more numerous than surface-visible magma vents; however, they are almost impossible to find without cheating via one of the utilities like "reveal.exe", since unlike proper magma vents these smaller deposits must be almost literally mined into to see (you will get a warning about "warm stone" before you actually breach the deposit). These smaller magma deposits appear in the same places as normal magma vents - near volcanoes, or, failing that, near other known magma.

The newly-added "Site Finder" feature neatly sidesteps all of this legwork, allowing you to search for a site with a magma pool or pipe without having to manually check each tile on the world map. Note that unless you edit the .init file so that magma features are shown on the local map, you won't know exactly where the lava is prior to embarking- just that it exists. Depending on whether or not you like a little mystery, this can be turned on or off at will.

Using magma

On a map with a magma vent, the magma will be clearly visible from every level ground and below, unless the map is in a Freezing area. In Freezing areas, the top few levels of the vent will have cooled to form an obsidian "cap". This should still be readily recognizable however, as it will comprise a circular area. The minerals directly adjacent to the magma vent will also be immediately visible, even at the lowest level of the map, which can give some hints about where to prospect for ores.

Obsidian "magmacap" as seen from ground level

The vent has a similar, circular shape on each level. However, it is not identical from one level to the next; some levels will have a larger or somewhat misshapen circle of magma.

The primary use for magma is to power magma smelters, magma glass furnaces and magma forges. (There are other uses, including defense, obsidian production, and possibly even garbage disposal.) To build forges, etc. on magma, at least one of the external eight squares must be above a square of magma.

This can be done most easily by simply building on ground level. The magma is visible from ground level but is actually contained one level below ground level, just like any ground-level water source.

To build underground, you will need to dig at least one tile of a channel above the location you wish to build the smelter or forge. Underneath this channel there must be magma, either directly from the vent or channeled from the vent. You can simply build a tunnel straight into the magma, or use channels to tap into the magma on the level below safely - this latter is easier if there is more magma on the lower level than the level on which you wish to build. Tapping into magma directly is usually safe provided that you are prepared for it (see Pressure note below). Magma is much slower than water, and can be stopped by a simple bauxite floodgate. Take care however if you are using a screwpump to pump magma into a tunnel/funnel with a cistern below - the pump will make the magma overflow as it would with water.

Volcanoes and magma tubes slowly replenish their supply of magma. A miner with less than Unbelievably Agile will die when breaching a magma tube as he can't move away quick enough.

Producing Obsidian

Magma can also be used to produce Obsidian, a stone which can be used to make swords at a Craftsdwarf's Workshop and which has a base value of 3 (compare with 1 for normal stone and 2 for flux). If you have a magma pipe and an inexhaustible source of water, you can produce an inexhaustible supply of Obsidian. One method: A reservoir must be built with a controlled inflow of water. The floor of this room should be channeled out and replaced with one or more retractable bridges, linked to a (single) lever. One Z-level below the reservoir a 'channeling area' should remain empty. This area should cover the full area beneath the bridges plus a single row 'ledge' to the west or left (Access is only required from this side). The area beneath the bridges should be channeled one Z-level further. The easiest way to do this is one row at a time, from east to west. The ledge allows the last row to be easily channeled. In the lowest Z-level, access for stone haulers should be from the east side, and controlled by a magma-safe floodgate. Inflow of magma into this area should not be from directly above, nor should it be pressurized by pumping to a higher level. If obsidian is created in the channeling area (rather than in the magma reservoir area below it) one or more bridges will have to be destroyed, re-built, and re-mechanized to resume proper function. Therefore it is important that magma enters this area from the side.

The two reservoirs should be filled to at least 2 units depth, to avoid evaporation. It is not necessary that the depths be balanced, only the area; water and magma are instantly destroyed when they come into contact, resulting in no spillover. In order to prevent flooding, the upper reservoir should be sealed before the bridges are retracted.

Magma flow

Magma safely diverted underground (cross section)

Magma is a chunky liquid and as such will not be forced upwards by pressure under normal circumstances.

Thus it can be safely passed through tunnels to be used at a lower point in the fortress.

A frequent mistake, however, is to assume that a channel is sufficient to cause magma to fall. While magma will not rise out of a channel, it can flow over the top once the channel fills up.

Another common mistake has to deal with magma pipes and volcanos in Freezing areas. Many people will channel into the obsidian cap and then into the magma through there. However, once a tile of the obsidian 'cap' is breached, the tile directly above the breach will then be included as part of the magma pipe and the magma will begin rising until it has filled that square. For fortresses that tapped into the magma, this can result in waves of magma slowly filling up the fortress from the bottom level up to the magma pipe's new top level. The magma can continue to rise all of the way to the surface if an entire section of the obsidian cap is channeled. The magma will not harden into obsidian again, though, just from the cold temperatures.

Danger: This will overflow (cross section)

(v0.28.181.40d:) Also note that screw pumps can cause magma to behave oddly. Magma that is emerging pumped from a screwpump will behave as if pressurized, and be forced upwards to the same level as the pump. However, this only occurs while the pump is actively pumping magma into a tile that is already full. It seems likely that this behavior is a result of code in the pump ignoring what type of fluid is being pumped, causing the pumped fluid to be passed to a connected tile as if pressurized. It may not be desired behavior, and thus may change in subsequent versions.

Pumps will cause magma to rise to the level of the pump (cross section)

Magma compared to water

Magma is a chunky liquid. As such, it acts like water in certain circumstances, but acts differently in others.

Similarities

• Magma fills a tile and has seven possible depths.

• Magma flows outward and downward to expand into clear space.

• Screw pumps work in magma.

• Floodgates and pressure plates work in magma.

• Constructed walls of all kinds safely contain magma.

• Objects thrown into magma sink to the bottom.

• Magma that is only 1 deep "evaporates" over time.

• A magma-fall generates magma mist, just as a waterfall generates normal mist.

Differences

• Magma is extremely hot, and capable of melting objects and constructions made of most materials (see Magma vs. built objects) and thus destroying them.

• Magma is not normally pressurized, it seeps out of holes slower than water and slow enough for any dwarves to outrun, unless they are the ones digging into it.

• Magma flows up from a direct vertical line from the bottom of a Volcano or Magma Pipe only. Otherwise, its level may rise only by dripping more magma from above, and new magma may only distribute itself by moving down or to the sides, but never up.

• Magma reacts violently with water, releasing steam and, depending on the amount of magma, leaving behind tiles of solid obsidian which can be mined, smoothed or engraved like any natural tile.

• Magma is not a water source. Dwarves can't drink it or supply it to their wounded.

• Magma mist, unlike regular mist, will burn whatever it touches.

Magma vs. built objects

Some objects that come in contact with magma will function fine, no matter what their material. Others will melt or cease to work properly unless they're made of magma-safe materials.

• Workshops that are powered by magma need not be built of magma-safe materials to function.

• Constructed objects like walls, floors, stairs and ramps can be made of any material, even those that are not "Magma-safe", and can come into contact with magma without issues.

• Like walls, doors can also be built out of any material and still hold back lava as long as it's in the "closed" position. It may be wise to make sure hallways/rooms close to an engineering project involving magma have plenty of doors, just in case you have a little too much fun when you forget to build that last floodgate.

• Bridges that are built over magma may be constructed of any material. However, bridges that are submerged in magma must be constructed of a magma-safe material.

• Most machines must be made of magma-safe materials to function for more than a few minutes in magma. This includes floodgates. Unsafe materials will function for a while, but then burn away. Screw pumps will not melt, but will burn. Stone blocks and copper pipes/corkscrews will not melt.

• Stone mechanisms attached to a construction will melt in magma unless made of bauxite or raw adamantine, even if the construction itself is made of steel. In addition, if the mechanisms melt off of a floodgate, the floodgate will cease to be "constructed" and become an unplaced item again.^{v0.27.176.38c} At this point, the magma will flow over it freely.

Magma creatures

Fire imps, firemen, magma men, and fire snakes inhabit Magma. Fire snakes are a type of vermin that can set your fortress on fire with little to no warning. Like all other vermin, they may spawn a short distance outside their native environment, meaning they can appear in any region near a magma pipe, even if the region and magma have no physical connection.

Temperature settings

Magma is almost harmless if temperature is disabled in the Dwarf Fortress init file. It can still trap and suffocate or simply starve your dwarves in some situations. It will not melt bridges, etc. constructed of non-magma-proof materials.

Magma reactions

• Water: If magma happens to contact water it produces some steam and obsidian. Steam is no longer deadly (as in the old 2D version) so steam traps are ineffective; however, it is now much safer to cast large volumes of obsidian inside mined or constructed molds. The resulting slabs of obsidian are functionally identical to native stone.
• Brooks: If magma comes in contact with a brook, it will not produce steam, but will turn the water tile below the brook to obsidian, and give the brook tile the appearance of a dried-up brook.
• Rocks: Rocks left over from mining will melt if magma covers them.
• Trees: Trees will not (yet) burn or be destroyed by magma.
• Speed: Magma moves relatively slowly. While it is nearly impossible to try to seal off water let loose, magma is slow enough for your dwarves to build a floodgate or door, or even wall off the flooding area, if you happen to let magma loose by mistake.
• Pressure: Magma does not transmit pressure.
• In a volcano or a magma pipe, magma will occasionally appear in small columns above its surface [1] if it is below its original level. It will not be created above floors. It will be created in 7s, and will probably spread around in few seconds. This may be deadly to unlucky dwarves standing around. Therefore, to be sure to avoid casualties, do not build workshops except at the highest level of magma.

Magma FAQ
Practically everything Magma related
What can I use to make magma-proof items?
How do I channel magma?
Digging designation canceled: Warm stone located
Where can I find magma?
Can magma cremate dead dwarves instead of burying them?
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