| Mountain | |||||
|---|---|---|---|---|---|
| |||||
| Maximum Population | No effect | ||||
| Town Bonuses |
 +5% Production | ||||
| Movement Point Cost |
 4 1 N/A | ||||
| Possible Minerals (Arcanus) | |||||
| Possible Minerals (Myrror) |
 Mithril Ore (common) Gold Ore (uncommon) Adamantium Ore (uncommon) Iron Ore (rare) Silver Ore (rare) Coal (rare) | ||||
| Change Terrain |
    | ||||
| Gaia's Blessing |
No effect | ||||
Mountain is a type of Terrain in the world of Master of Magic. Mountain tiles are very common on both Planes. They may appear in any formation, whether as isolated peaks, long ridges, or even large swaths of Mountainous terrain (especially on Myrror).
Mountain tiles are worthless for habitation or agriculture, giving no Maximum Population bonus to nearby towns. On the other hand, Mountains do give a respectable bonus to Production.
Furthermore, Mountains may contain a very wide array of Minerals, particularly those that give 
Gold output or Production bonuses. On Arcanus, Mountains will often contain Coal or Iron Ore. On Myrror, it is fairly easy to find Mountains filled with valuable Mithril Ore or even Adamantium Ore. As a result, towns located near mineral-laden Mountains are often great at producing new Normal Units.
Mountains are the most difficult terrain obstacle for Walking units, which will normally spend all of their Movement Points entering these tiles.
The Change Terrain spell may be used to flatten a Mountain tile, turning it into a Hill tile. Restoring a Mountain tile is a more complicated process, and would require the use of Raise Volcano. The Gaia's Blessing spell has no effect on Mountain tiles adjacent to the affected town.
Description
The surface of a world is not as static as it may seem to short-lived humanoids. It is actually broken into several pieces, known as "tectonic plates", which float on top of a layer of lava. These plates move very slowly, but across many millions of years they tend to drift apart and collide with each other. In cases where two plates collide with sufficient force and at a certain angle, a Mountain will slowly rise out of the ground at this pressure point.
Mountains are made primarily out of solid rock. Their jagged edges (common especially in younger Mountains) and the high altitudes to which they rise cause a decided lack of animal and plant life. They are also completely unsuitable for agriculture, since most cultivated plants will simply refuse to grow on them.
On the other hand, the huge pressure that causes a Mountain to rise, as well as the pressure that the rock itself exerts on whatever is underneath it, lends itself to the creation of seams of valuable Minerals. As humanoids learned to dig into this rock, they quickly discovered that vast quantities of precious metals and dense, flammable substances can be extracted from inside the Mountain, aiding in construction and technological development.
As a result, mining towns often appear wherever a rich mineral deposit is located, focused almost entirely on carving out these riches. Though such towns rarely thrive, due to limited food supplies and a harsh environment, they can nonetheless be of great strategic importance thanks to these mineral resources.
Geography
Mountain tiles are a common sight on both Planes. They appear in every latitude and in any configuration. Some Mountains are completely isolated; peaks rising out alone in the midst of an otherwise-flat area. Mountain ranges are also common, where a string of Mountain tiles form a sort of barrier across the landscape. Finally, and especially in Myrror, Mountains can form entire regions of elevated barren terrain.
Mountains, and especially clumps of Mountain tiles, are often the starting point for Rivers - which flow downhill until they reach an ocean or inland lake. Hill tiles are often found adjacent to Mountains (i.e. "foothills").
Town Development
Mountain tiles pose a serious problem for proper town development, since they bestow no bonus to the Maximum Population of nearby towns. This makes settlement in Mountainous regions more difficult, restricting growth rates and potential of such settlements.
On the other hand, Mountain tiles are very beneficial for boosting Production in nearby towns. A town near several Mountain tiles can have a Production rate many times higher than a similar-sized town in flatter regions. The presence of Minerals in mountains, especially Minerals that aid in Normal Unit production, result in small towns being built in such regions simply to capitalize on these resources.
When constructing a new town in a Mountainous region, it is therefore important to balance the number of Mountains in the town's catchment area with other tiles that can aid in 
Food output and Maximum Population. River tiles and Grasslands are great for solving this problem. A town completely surrounded by Mountains will not grow at all!
Maximum Population
- Main article: Maximum Population
Mountain tiles are among the few Terrain types that provide absolutely no bonus to a nearby town's Maximum Population.
In other words, if a town were to be surrounded entirely by Mountain tiles, its Maximum Population would be exactly 0. This means that not only will the town not grow at all, but will actually lose a few citizens each turn. Fortunately, negative Population Growth cannot destroy a town (it will never drop below 1,000 population due to negative growth), but will likely never grow above 1,000 either. This makes Mountainous areas extremely unfavourable for settlement.
Maximum Population dictates the absolute maximum number of citizens a town can have. Once it reaches this many citizens, it will simply stop growing. Maximum Population also determines the town's Growth Rate: the larger the gap between the town's current population and it's maximum population, the faster the town grows.
Furthermore, Maximum Population also determines how much Food can be produced in a town before inefficiency sets in. Once this limit of Food production is reached, additional citizens assigned to Farmer duty will produce much less Food - thus being inefficient. Higher Maximum Population means a higher Food production efficiency threshold, thus allowing more Farmers to be assigned and still have full efficiency.
As a result, in a town surrounded by Mountains, only a very small amount of Food can be produced even if all citizens are set to Farmer duty. It may struggle to produce enough food to feed itself - again resulting in negative Population Growth, and struggling to gain more than a few citizens.
To counter this effect, if a town is set up near a Mountainous area, make sure that it also has access to high-yield terrain such as Grassland, River, River Mouth, or Forests with the Wild Game mineral. This will offset the poor fertility of the Mountains, allowing the town to grow at least a little. This will help the town make good use of the Minerals found in the nearby Mountain. If no Minerals are present though - you may want to reconsider building a town next to the Mountains at all!
Production Bonus
Each Mountain tile within a town's vicinity provides that town with a Production bonus of +5% - the highest Production bonus of any Terrain type.
This 5% is calculated based on the total amount of Production yielded by the town's Farmers and Workers. For example, if the town's population gives a total of 100 Production, each Mountain tile in its vicinity adds +5. Note that total production is rounded down to a whole number, but only after all bonuses have been added together. For reference, point the survey tool at a town or proposed site for settlement to see the total Production bonus given by all tiles within its catchment area.
Increased Production is very useful, as it speeds up construction times of both Town Buildings and Units. With the Housing or Trade Goods projects it is also possible to turn this extra Production into Population Growth or Gold (respectively).
If the proper Minerals are present (see below), a town in a Mountainous region can become a good unit-production center.
Common Minerals
Mountain tiles can contain a wide variety of different Minerals - similar to those found in Hills. The distribution is different however, with Coal being common on Arcanus Mountains, and Mithril Ore very common on Myrror.
It is often very tempting to try and exploit every possible resource, including those found in Mountains. However, Mountains present a difficulty due to limiting nearby towns' potential growth. Furthermore, the types of Minerals often found in Mountains contribute mostly to unit production. As a result, it is often best to try and place a town that can harvest two or more Minerals simultaneously. Such a town would be able to produce high-quality units very quickly. This is especially true if the town also has access to several Food-producing tiles. On the other hand, if no such tiles are present near the Mountains, a new town placed in such a region may fail to grow to any sufficient size, and remain useless.
Coal is the most common Mineral found in Arcanus Mountains, though it is also present on Myrror Hills. A town built close to a Coal deposit can produce units at a faster rate than normal. In game terms, the cost of Normal Units in this town is reduced by 10% for each Coal tile within its catchment area.
Iron Ore is also quite common in Arcanus Mountains. It is a less valuable variety of Coal - decreasing the cost of Normal Unit construction in nearby towns by a factor of 5%. Towns built next to this mineral can produce units slightly faster than normal, especially if the town also benefits from the Production bonus of several nearby Mountains and/or Hills.
On Myrror, Mithril Ore is the most common Mineral found in the Mountains. It can also be found on Arcanus, but is less common. By default, it provides nearby towns with 
+1 Power, augmenting the magical prowess of the town's owner by a small amount. Furthermore, if the town can build an Alchemists' Guild, it can start producing units with 
Mithril Weapons, making them stronger in both attack and defense properties.
Myrror Mountains (only) also frequently contain Adamantium Ore. These provide a bonus of +2 Power to nearby towns - twice as good as Mithril Ore. Again, with the construction of Alchemists' Guilds in those towns, all new Normal Units built there will be equipped with 
Adamantium Weapons, which greatly boost these units' combat performance!
Gold Ore and Silver Ore are mildly common in Mountains on both planes (with Gold Ore being significantly more common in Myrror Mountains). Gold Ore will provide a +3 bonus to any nearby town, making a good place for a financial center to develop. Silver Ore will provide a nearby town with +2 - a small but not negligible amount.
Movement
Mountains are easily the most difficult terrain obstacle for most Walking units. Such units lose 4 Movement Points when entering a Mountain tile. As a result, a Mountain ridge forms a good natural barrier against invasions - giving you ample time to prepare your defenses as the incoming enemy army struggles to scale the ridge.
Units possessing the Mountaineer trait, as well as any other units stacked with them in the same army, will only take 1 Movement Point to enter a Mountain tile.
Flying units treat Mountain tiles like any other tile. They take only 1 Movement Point to enter it.
Units with the Non-Corporeal ability can enter this tile at 0.5 Movement Points.
As land tiles, Mountains are completely impassable to units possessing only a Swimming ability.
Roads and Road Construction
As with any land tile, Mountain tiles can be upgraded with a Road. This is done using Engineers, who are only available to certain Races.
Constructing a Road through a Mountain tile is a very difficult endeavour. A single unit of Engineers will take 8 turns to construct a Road on a Mountain tile. Each additional unit of Engineers reduces this by about 50% (rounded up). Therefore, 2 unit will take 4 turns, 3 or 4 units will take 2 turns, and 5 or more units will take only 1 turn to build this road. Additional Engineers (beyond 5) do not speed this up any further.
Dwarf Engineers work twice as fast as other Engineers. This means that a single Dwarf Engineers unit can complete a Road in a Mountain tile in only 4 turns, 2 Dwarf Engineers will take 2 turns, and 3 or more Dwarf Engineers will only take 1 turn to complete construction of a Mountain road.
Once a road has been constructed, the cost to enter this Mountain tile changes to 0.5 for all units, regardless of their movement type. Note however that Swimming units still cannot enter this tile, since they cannot move on land.
If the road was constructed on Myrror, or affected by the Enchant Road spell, movement costs to enter this tile are completely removed for most units. In other words, Walking and Flying units can enter this tile without spending any movement points. Non-Corporeal units cannot use this special road, and will still require 0.5 Movement Points to enter the tile.
Change Terrain
The 
Nature spell Change Terrain can be cast on any Mountain tile. When this spell is cast on the tile, it will turn this tile into a Hill.
Though the tile loses almost half of its Production bonus ( +5% is reduced to +3%), it also becomes most habitable, giving a Maximum Population bonus of +0.5 to any nearby town. This is exceptionally useful as it can allow a town built in a Mountainous region to grow larger and thus capitalize better on the Production bonus of other nearby Mountains.
Note that the change causes no damage to any Mineral present in the tile. Thus, a town located near such Minerals can utilize Change Terrain to increase its Maximum Population without hurting the bonuses from those minerals.
Changing tiles into Mountains
With the same Change Terrain spell it is possible to calm down Volcanos, turning them into Mountains. Note that since Volcanos do not occur naturally (except those containing Chaos Nodes, which cannot be affected by Change Terrain anyway), this is quite rare. It requires that either you or another wizard cast the Raise Volcano or Armageddon spell first.
If you possess both Raise Volcano and Change Terrain, you can use this strategy to augment the Production output of your largest towns - by placing one or more Mountains within their immediate area. As long as you do not sacrifice too much of the town's Maximum Population as a result, you can end up with very large towns that get respectable Production bonuses - with very favourable results.
Remember however that each Volcano raised by your own Raise Volcano or Armageddon spells gives you a constant +1. Therefore, if a Volcano you created is not within the catchment area of any town, there is no point in harming that Volcano.
Also note that as of patch 1.31, each Volcano existing on the map has a small chance at the start of each turn to automatically transform into a Mountain. The "Read Me" file for this patch also mentions that such a transformation may yield a new Mineral on the tile, but this is as yet unconfirmed and may or may not actually work as intended.
Gaia's Blessing
The Gaia's Blessing spell will not affect the Mountains surrounding the enchanted town.