|As of Master of Magic v1.31, Wall of Darkness is known to be malfunctioning in at least one way. Please read the Known Bugs section below.|
|Wall of Darkness|
|Spell Type||Town Enchantment / Combat Instant|
|Combat Casting Cost||40|
|During combat at the enchanted town, only units with True Sight may use a Ranged Attack from outside the 4x4 "town-proper" area at targets inside this area.|
Wall of Darkness is an Uncommon Town Enchantment belonging to the Death Magic realm. For 40 it may be cast during siege combat in a Town to surround the 4x4 "town-proper" area with a wall of shadowy clouds. Units outside this area may not make a Ranged Attack against units inside this area, unless they are enchanted with True Sight. Units inside the area may freely use Ranged Attacks against units outside the area. Both enemy and friendly units are affected in exactly the same way.
The same spell may be cast on a friendly town on the overland map to achieve a lasting effect: the Wall of Darkness appears in each battle fought in that town. In this case the Casting Cost of the spell is 200, and maintaining it requires an Upkeep Cost of 5 per turn.
Wall of Darkness forms a completely black barrier of smoke and shadow that surrounds the outskirts of the targeted Town. The barrier is so opaque that units outside it may not make any ranged attacks at units on the other side. Strangely enough, the barrier appears to block light only in one direction - making it possible for the town's defenders to freely make ranged attacks against units on the outside.
Ranged Attack Barrier Edit
Wall of Darkness' effect is felt only during combat taking place at the enchanted Town. On the battlefield map, the 4x4 tile area representing the town proper is surrounded by a visible black-cloud barrier. This barrier indicates the town's perimeter.
Units outside this area (usually the army besieging the town) may not make any Ranged Attacks at units inside the wall (usually the town's defenders). Any attempt to do so results in a red error message appearing on screen, and no attack is made.
Whether the attacking unit is friendly or not doesn't actually matter though. Only the position of the attacker and the target matter. Units on the inside of the barrier may use Ranged Attacks freely against any target, as normal. The barrier does not affect these attacks in any way.
Units possessing True Sight from any source are immune to the effect of Wall of Darkness. Due to a bug, however, units with innate Illusions Immunity are not. This is contrary to the spell's in-game help.
Wall of Darkness may be cast either on the overland map or during combat. Its effect is the same, but there are differences in Casting Cost, Upkeep Cost and long-term implications between these. Both versions may be dispelled during combat (with Disenchant Area or Disenchant True). However, if the besieging army fails to take the Town (i.e. loses the battle), the overland version is only suppressed temporarily, will reappear after combat, and may continue to apply in subsequent battles.
Overland Version Edit
On the overland map, Wall of Darkness may be targeted at any friendly Town that is not already affected by it. The overland version of the spell has a Casting Cost of 200. It also requires an Upkeep Cost of 5 per turn, which is automatically paid out of its caster's Mana Pool at the start of each turn. If there is insufficient Mana in the pool at the time, the spell will dissipate immediately.
Upon casting the spell, the game automatically opens a pop-up window showing the town view. A few moments later, a long stretch of black clouds will appear near the bottom of this view, outside the City Walls (if the town has them), to indicate that the town is now protected by a Wall of Darkness. The dark barrier itself will appear during any combat that takes place at this town, so long as the spell remains in effect.
The caster of Wall of Darkness may remove it by examining the town's details and clicking on its name in the town's Enchantments list. This will bring up a confirmation dialogue for releasing the spell. The primary reason to do this would be in order to remove the spell's Upkeep Cost, thus conserving Mana for other spells.
Combat Version Edit
Alternatively, it is possible to cast an impromptu version of Wall of Darkness during combat. It is available for casting only when defending a friendly Town. This version of the spell has a Casting Cost of only 40. However, its effect will only last until the end of the battle, and will dissipate immediately afterwards. This also means that it has no Upkeep Costs, as it doesn't linger at all.
Wizards who possess at least 8 Spellbooks, or Wizards with 11 Spellbooks who did not select Wall of Darkness as a guaranteed spell, will be able to Research this spell at some point during their campaign. Wizards with fewer than 8 Spellbooks have a random chance of being able to Research it. The chance for this spell to appear increases with the number of Death Spellbooks the Wizard possesses or obtains during gameplay.
Wall of Darkness has a base Research Cost of 680.
With at least 1 Spellbook, the Wall of Darkness spell may be acquired as a reward for winning encounters in creature Lairs, Towers, et cetera, or when conquering the Fortress of a rival wizard who has already researched this spell.
Wall of Darkness' effect is pretty specific - though it can be very useful in some situations, it is useless in others. This makes it difficult to decide whether to cast the spell on the overland map and bear its Upkeep Costs, or simply use it whenever necessary during battles.
On the one hand, Wall of Darkness is a great defensive mechanism for sieges. Enemy Ranged Attackers are always a nuisance, and the opportunity to reduce their effectiveness (essentially - neutralize them) is a great advantage.
As a result, Wall of Darkness is usually better cast as a Combat Instant when the town is attacked by an army with plenty of Ranged Attackers, or contains a few very-strong Ranged Attackers. This conserves Mana, as the spell costs only 40 and has no further upkeep costs.
Again, when in a war with an enemy that deploys many Ranged Attackers, casting Wall of Darkness as a Town Enchantment may end up saving more Mana in the long run. But this would have to be a pretty bloody war - possible against Dark Elves (most of whom can use Ranged Attacks) to justify the increased costs.
Known Bugs Edit
Contrary to what is stated in the in-game help text, units with innate Illusions Immunity may not actually attack units inside a Wall of Darkness. This affects two ranged Fantastic Units by default (Shadow Demons and Demon Lord), in addition to any Ranged Attack units turned into Undead creatures. Interestingly enough, the True Sight spell, which is supposed to grant this same immunity, works as intended. However, this will generally be impossible to obtain for a Wizard possessing the affected units.