Through the use of soul gems MG can use magic in the form of pre-made Spells that can be purchased with points once the necessary Grimoires have been unlocked. MGs also get their Signature Magic, which is not purchased and does not use the classifications of ordinary spells.
The mana cost of spells is given in Stat Point Calculations, and the point cost in Point Madness.
Willpower affects the power of spells, and an MG's mana cap.
Spirit determines your finesse over spells, meaning how quickly you can cast them, how much you can modify or aim them, how well they penetrate through magic resistance. It also determines an MG's mana regeneration rate. The regeneration rate can be temporarily lowered by using too much mana.
Spell tiers:
Spells are in tiers: tier 1 = levels 1-99, tier 2 = 100-199, tier 3 = 200-299, etc. The highest level MG is currently in the 500-599 range.
Spell classes:
Spells are further categorized by “class” (which has nothing to do with MGs' classes). The classes range from D through S.
[D-class spells should be able to be cast 100 times if it is the lesser quality before reaching zero mana. C-class spells would take 50 times, B-class 20 times, A-class 10 times, and S-class 5 times. There is also a sixth category, Finale-class spells, but you don’t unlock the capability to use or purchase those until level 200, and they have other restrictions.] Selene, ch. 36
[… at tier one, all Guardians begin with 300 mana by default. Therefore, a D-class lesser spell should cost only three mana. At level 100 when you unlock the next tier of Vaults and Grimoires, the average maximum mana should be around 1,785, meaning a tier two D-class spell of lesser quality would cost eighteen mana if rounded up.] Selene, ch. 36
On 4-28-2025 at 2:10 on #mgg-general, Mika posted:
The class scaling is hard to simply codify (USUALLY) because higher class spells tend to be more complex, having more effects tacked on rather than just a simple raw power difference. That being said, some spells do have straight up class upgrades. Example: A D-class fireball might do damage and have a small explosion. A C-class fireball would do more damage, have a bigger explosion, and might have higher chance of setting things on fire, meaning the raw power scaling would be different. In summary, the power of spells costing similar levels of mana but having a different class is usually hard to compare. Higher class spells usually means additional or more complex effects tacked on along with greater power. A lower class spell at the same mana cost might do more RAW damage, even, but usually the additional effects of a higher class spell more than make up for it.
Spell qualities:
All spells come in three ‘qualities’, ‘lesser’, ‘adept’, and 'greater'.
[… the adept version is fifty percent more powerful than the lesser quality for twice the mana cost. The greater version is twice as strong as the lesser for three times the mana cost. This three version pattern applies to all spells.] Selene, ch. 36
Spell slots:
aka how many spells you can have prepared.
The mechanics of spell slots has changed between editions.
New version:
[Hmm. Two things. First is that while you can purchase an unlimited number of spells, you can only have a set amount of “active” spells. You start with seventy spell slots and gain ten more every hundredth level. If you have more purchased spells than active slots, you can change which ones are considered active at any time, but the change will only take place at midnight UTC, which is two in the afternoon here in Arcadia. Finally, the lesser, adept, and greater versions of a spell all share the same spell slot instead of each taking one individually. This lets a Guardian keep quite the repertoire of spells available to them without needing to worry too much about their choices.
“What about tiers? Do higher tier spells take up more slots?”
[No. There are also a few passive Skills you can take to increase the number of spell slots you have, but those Augments are usually only chosen by MGs who focus on casting. Still, having a large variety of spells to handle any situation can be a large factor in survivability and effectiveness so long as you are not consumed by choice paralysis.]
Old version:
“Spells are soft capped. You can buy and know as many as you want, but you can only have so many prepared a day.
You current level = current spell cap, BUT spells in higher tiers require higher tier spell slots. For instance, at level 101 and beyond you earn tier two slots instead of tier one. A tier two slot can also be exchanged to learn two tier one spells.
And classes/Skills can increase your spell cap.” Mikasane Discord
Finale-class Spells:
At level 200, an MG either gets or gets access to a Finale-class spell. This is an especially powerful spell, and seems to be tailored to the MGs theme, maybe even to their signature.