Spell works a bit differently, than in the Heroes of Might and Magic series. Your mana pool is generated for your whole empire, and you can cast all of your spells on the adventure map, rather than in combat. Also, spells can turn the tide of any battle, so you just can't ignore them, and focus solely upon leveling up your party. Spells are divided into 5 levels. While 1-4 are available to all hero types, level 5 is accessible only for mage lords.
Developing and casting spells cost mana, which is provided by mana sources. Each nation has it's own respective, primary mana source (Empire - Life, Undead Hordes - Death, Clans - Rune, Legion - Infernal, Elves - Grove). Gathering primary mana only allows you to cast spells up to level 2. Above level 3 you'll need to collect other factions' primary mana sources too. You may also buy and find spells around the map.
Mana sources are scattered around the map, and controlling them is crucial. Your capital produces a very miniscule amount (25/day) from your primary mana, and usually there are sources near your capital, but that still shouldn't encourage you to turtle in, and hope for the best.
Here's a chart about the importance of the mana sources for the given factions (1st is the most important, 4th is the least important). Apart of a few occasions, the less important mana source will only be needed for level 5 spells, but denying a crucial type of mana for the enemy is always a good idea.
- The Empire: 1. Life 2. Runic 3. Infernal 4. Death
- Mountain Clans: 1. Runic 2. Life 3. Death 4. Infernal
- The Undead Hordes: 1. Death 2. Infernal 3. Runic 4. Life
- Legion of the Damned: 1. Infernal 2. Death 3. Life 4. Runic
- The Elven Alliance: 1. Grove - as Elves are the only one who use that, protecting grove sources is imperative
Apart of a few occasion, spells first needed to be researched in your capital, which costs quite a lot of resources, unless you are playing with a mage lord hero. You may also have to build a mage tower with the Warrior and the Guild lord heroes. You can research only one spell per day, and casting is also limited for one occasion per spell per day. Mage Lords also have an edge here, as they can cast the same spell twice on each day.
You can find different staffs scattered around the map. You can use them only if your hero has the "Use staffs and scrolls" ability, or hire a Level 1 mage hero in one of your city. Using staffs requires mana, but the twice-a-day bonus for mage lord players applies for staff spells as well. Even better, if you know the same spell from your capital's library, once you casted the spells from the staff, you can still cast the "standard" version - even twice, if you're a mage lord hero. The good thing that staffs won't expire with their use, and you can cast them in the following turns, as long as you have mana for it.
Just like above, scrolls can be found or be bought from the adventure map. You'll need a hero with the proper ability to use them. Though scrolls are one-use-only items, have no mana cost, making them extremely effective in games, where you're low on funds.
CapitolEditThis is the source for all of your spells. For Warrior and Guild lord player spells are limited to Level 4, and research costs twice as much as for a Mage Lord Hero. On easy difficulty you'll also acquire your enemy's researched spells, if you destroy their capitals.
A note on casting: apart of damage spells you cannot cast the same spell twice on a single unit, but 2 different spells with the same effect will add up. Ie: adding a Holy Shield and an Ice shield gives you 30% (20%+10%) armor. Dropping Rust and Tormentio on the same unit removes armor entirely (2*(-50%)armor).
Spell overview for each factionEdit
The Empire is almost all about the "buff" spells. The chart is impressive, but sadly, most of them have some serious setback, and at the end of the day you'll get to use about half a dozen.
You can research elemental wards, and mind-ward, but many of them have exceptions for certain kind of attacks (Paralyze for Mid Ward, d'oh!). You also find here the broadest selection of healing spells - which also won't see much use, since your party's support units will do the job without spending the valuable mana. Their summoned creatures are nice, and the spells of "Strength", "Healing", "Haste", "Holy Armor" and "Call to arms" are very good. On the offensive there's not much to write home about, as they're either meager (Lightning on Level 1), or become available only on higher levels, with steep price tag.
Their most valuable asset is the "Daylight", which removes the fog of war altogether. On level 5 you will find 2 healing spells (a single-target, and a map-of-effect version), death ward, and your strongest attacking spell with 125 points of damage.
The Mountain Clans
A very nice mixture of offensive and defensive spells. For offensive ones, your summoned creatures are plain average, but you'll get reasonably priced damage spells on each level from 1 to 4. The support spells are even better. You'll get "Healing" from the Empire, plus some dirt-cheap travel spells ("Forestwalk", "Seafaring", "Chant of hasting"), which speed up your earth-bound heroes considerably. With damage enhancing spells you can boost your damage to ridiculous level (easily reach the maximal 300). Though you don't have healer, on level 1 you'll get the Ice shield, which gives you 10% armor. Even this small amount can be crucial in a capital assault. "Chant of Fortitude" on level 4 raises it with an additional 33%. And now, the icing on the cake, the level 5 spells. "Wotan's Chant" gives an additional 50% damage buff, whereas "Ancestors Call" gives +33% armor for ALL OF YOUR UNITS ON THE MAP! That means 76% armor from spells alone, even for your frail Tenderfoot. No wonder, that Clanner scrolls and spells from the shops are among the most valuable assets.
The Undead Hordes
No surprise that you won't find any buff spells here. The Hordes are strong in cursing and debilitating their opponents. As you cannot cast spells into cities, that makes capital sieges a bit difficult, so you have to find other ways to get the much needed armor protection.
Summoned creatures are OK, and you'll get nice offensive spells on each level. Heck, even on level 1 a mage lord hero can dish out 60 points (4*15) of damage - which is especially useful, if you have an ample supply from death mana, but scarce stockpiles from the others.
For the debuff spells consider "Rust" (-50 armor), along with "Curse of Nygrael" and "Rot" (-15% and -33% damage), which technically equals for the same level of armor protection. Spells, which mess with fog of war COULD come handy, however, in my experience the computer will cast you spells, even when it is not supposed to know your location.
On level 5 you'll find 2 very strong offensive spell, and the only buff spell - damage ward, which makes werewolf from your whole party against the first strike.
Legion of the Damned
Same can be said as for the Hordes. Many offensive spells (mainly from fire and mind sources), and a couple of good summoning spells. What makes this faction unique is the feat that you can summon illusions of those creatures. They won't do too much against AI players though, and you'll still have to pay 50-100% of the infernal mana requirement of the spell. Those stuffs, which render you invisible, are much more reliable than the FoW manipulating spells. However, they immediately wear off when you do something with the party outside of moving (even trading with merchants wears your camouflage off).
Among the debuff you have the same armor eating spell, as for the Undead, but the initiative and accuracy debuff is nowhere as good as the damage reduction. However, there's one pretty evil spell, which also comes in the form of a staff. That is the "Paraseus", which completely depletes the target's movement points for a day, to zero. Escaping rod planter? Enraged dragon, high on your heels? Wounded hero, en route to the city's presumed safety? Ranger with 100 movement points? Not anymore! The AI never casts travel spells, and pinning the key parties to the ground will not only let you outmaneuver them, but they'll be also sitting ducks for your attacking spells. Even better, as you drain all of their movement point, not even spells like "Chant of Hasting", or "Haste" will allow them to move (+X% to zero is still zero).
The Elven Alliance
The Elves have a very varied mixture of spells. Most of their usability is highly situational and/or controversal. Their travel spell restores only 30% of your movement points, but usually Elven heroes have higher-than-average movement values. Forest-creating spell can also hinder non-forestwalking heroes, however, it is utterly useless against flying ones. Their attack spells cause average damage (and comes with the most boring animation in the game, but that's another story).
The more exotic one called "Sinkhole" allows you to destroy an enemy rod on the map, enabling your planter to make a "pop-and-drop" attack, instead of wasting 2 turns (or 1 turn + a travel spell) to create a single rod. Their summoned Ents are not bad, but they will rarely change the game with their appearence. Also, there is one other interesting spell that increase Hp of all units in enchanced patry by 50 (from 145 to 195 for example ). While not as good as armour buff, it still can be crucial in heavy fights, because it allows party to withstand one more hit than ususal.