Combat magic

How a mage casts in battle: orders, casting time, aiming, penetration and magic resistance, fatigue and gems, and what the manual leaves open.

verified 6.37updated 2026-10-02 · Jake9 min read

Some spells can only be cast during a fight. They do things that mean nothing on the map: they wound, shield, cheer, calm or tire the units on the field. This page follows one such spell from the order that sets it up to the moment it lands. It covers how a mage is told what to cast, how long the casting takes, how the spell finds and hits its target, how a target can shake it off, and what it costs the mage in fatigue and gems.

Every figure comes from the manual. We have not re-measured anything here, so the page reports what Illwinter says the rules are, and the last section lists what the manual does not say.

Telling a mage what to cast

A commander who can cast gets its spells through battle orders. The script holds at most five specific orders, each good for a single round; once they run out, a general order governs what the commander does until the fight ends. The number keys let you copy a finished script onto another commander, which saves retyping it for a row of mages.

Four of the orders matter to a caster:

• Hold or cast a spell. The commander stays where it is, except that it casts a spell if it can. The AI picks the spell.
• Cast a specific spell. The commander casts the spell you named, provided it holds the gems and a valid target is in range. If either condition fails, the AI chooses a spell instead. The script does not simply skip the round.
• Cast spells, a general order. The commander casts whatever the AI chooses for the rest of the battle.
• Advance and cast spells, a general order. The commander moves up toward the front and casts, and the manual says a few spells may be cast on the way.

A third general order, Stay behind troops, has the commander cast and fire missile weapons while trying to stand in the rearmost part of the army.

A commander that receives no orders at all is given orders by the AI. The wiki’s army management page covers squads and the other orders.

Two limits on scripting are worth knowing. Spells that need gems need those gems to be in the commander’s inventory before the battle begins, so you cannot fetch them mid-fight. And you may script a spell the mage lacks the skill for, as long as the inventory holds the gems that make up the shortfall (see the gem section below).

Casting time and interruption

A spell is not instant. The manual divides a cast into preparation and recovery, each about half of the whole. The caster is vulnerable during preparation. Most spells take roughly one combat round in all, while battle enchantments and spells that use up gems often take longer.

A caster who is damaged while preparing can be interrupted. The chance is the damage dealt, as a percentage of the caster’s full hit points, plus 25. The manual’s example: a blow that takes off half the mage’s hit points gives a 75 percent chance of breaking the spell.

Two kinds of unit are half as likely to be interrupted: those with the combat caster ability (the paladin is the manual’s example) and mindless units. Monsters that cast innately skip preparation altogether and ignore the differing casting times.

Range, precision and area of effect

Spell tables in the manual’s appendix list, for each spell, a range (Rng), an area of effect (AoE), a precision (Pre) and a damage value (Dmg), along with the number of effects and special flags. The manual does not explain the unit that range is measured in on the battlefield, and it does not say how a spell with a low precision rating misses; see the end of the page.

Spells that deal damage are resolved much as missile weapons are. A mage has a precision attribute just as an archer does, and each spell has a precision rating too. For the purpose of the calculation the two are added together.

An area of effect lets one cast reach several targets. The manual points out two consequences. In a fight with mounts, an area hit can strike both a rider and its mount. And the obstacles scattered across the battlefield, such as bushes and rocks, have their own stats and can be damaged by attacks with an area nearby.

Protection and resistance

Damage from a spell is stopped in one of three ways, according to the spell’s flags.

• A normal spell meets the target’s protection like any other hit.
• An armor-piercing spell, marked AP in the tables, counts only half of that protection. Acid Bolt is the manual’s example.
• An armor-negating spell, marked AN, ignores protection entirely. The target’s only defence is the die roll. The manual gives Orb Lightning as its example.

Some spells skip protection and test the target’s magic resistance instead. The manual calls magic resistance a protection from magic that is usually all or nothing. Against some spells a successful check does not save the target outright, but reduces death to crippling injuries.

Penetration and the resistance roll

Many spells, mostly Astral ones, have to beat the target’s magic resistance before they have any effect. A spell with the note that magic resistance negates it is settled by two rolls.

• The caster makes a penetration roll: a flat 11, a DRN, and half of whatever skill in the spell’s path the caster holds above the spell’s requirement.
• The target’s roll is its magic resistance, plus a DRN, plus half of its own skill in that path.

The caster wins a tie. Most targets have no magic skill at all, so their side is usually their resistance plus the DRN. The resistances page covers the same roll from the target’s side, and the other things that ask for it.

Easy to resist, hard to resist

A spell marked MR is settled as above. A spell marked MR- is easy to resist: the caster takes a -4 on the penetration roll. The same rule says a spell that is hard to resist gives +4 instead. The manual’s spell key writes the easy case as a +4 to the target’s resistance, which has the same effect on who wins the comparison.

Skilled casters, and items that boost penetration, improve the odds. The same rules apply to battle enchantments that keep acting on units and call for a resistance check each time.

Spells that cannot be resisted

The manual does not give a list. What it does say is that not every spell has to get past magic resistance, and the spell tables flag the ones that do with MR or MR-. We read no more into an unflagged spell than that. Some spells are also barred from certain targets. The tables mark a spell as ineffective against undead, inanimate, mindless or spirit-form units with the immunity flags, which is a separate rule from the resistance roll.

Friendly fire

The manual says nothing about area spells hitting the caster’s own side, and we make no claim either way. Some spells are also marked as affecting the entire battlefield (BF in the tables), which the manual lists as a flag and does not discuss further.

Fatigue and gems

Casting costs fatigue just as attacking does. Each spell lists a fatigue cost. A mage whose skill in the required path exceeds the spell’s minimum pays only a fraction of it: one part in one plus the extra levels. One extra level halves the cost, two extra leave a third, three leave a quarter. On top of that the caster pays its own base encumbrance plus twice the encumbrance of every piece of armour it wears, for every spell. That second part does not shrink with skill. The manual’s reason is that magical gestures are harder in heavy armour.

The manual calls fatigue the limit on most casters in battle, and it names Reinvigoration and Relief as useful for the same reason. The fatigue page works through the thresholds: what a tired unit loses and when it falls unconscious.

Gems change both the skill needed and the cost. A mage that spends a gem gains one skill level in that path for that one spell. The extra level can let it cast a spell it could not otherwise reach, or cut the fatigue, or both. Three limits apply:

• A mage can use no more gems in a turn than its current skill level in the path.
• A mage can never raise its skill by more than one through gems.
• A mage with no levels in a path cannot gain any by using gems from it.

If you leave spare gems in a mage’s inventory, the computer will spend them to cut fatigue on spells the mage already knows. The player does not control that use, except for the “conservative gem use” box, which makes the mage spend gems only on scripted spells and as sparingly as it can. A spell that raises a mage’s skill for the length of the battle is a different thing from a gem. A gem helps one spell in one round; the spell helps for the length of the combat. See gems and magic paths for the resource side. When mages share a cast in a communion, the cost is split among them; the communions page has the rules.

Battle enchantments

A battle enchantment affects the whole field. The manual says some last for the length of the battle and that each one ends if its caster dies. Every battle enchantment and every temporary magic effect is dispelled if the fight lasts until sunset. We do not cover individual battle enchantments here.

What this page does not cover

The manual does not say how large the unit of spell range is, or how precision turns into a miss. It does not say how area spells treat friendly units. It gives no list of unresistable spells, and it does not say how the AI scores its choice among spells, only that it picks one. We leave these out until a source states them.