Magic points

Version 0.18: This article may not be up to date for the latest stable release of Crawl.

Magic points or Mana points (usually abbreviated to MP) is the amount of magical energy which a given character has. It is used for spellcasting, for invoking divine powers (with the exception of Trog) and for evoking abilities granted by worn items, mutations, and intrinsic abilities.

Having your MP fall to zero is not directly lethal, but can be very hazardous for a spellcaster. MP will regenerate up to your maximum with time, and it is often recommended that spellcasters should rest up to full MP after every fight.

Some items like rings of magical power or staves of power can increase a given person's reserves of magical power.

Your maximum MP without benefit of items is a function of your experience level, your race, and whichever of your Spellcasting, Evocations, and Invocations skill is higher. Training Spellcasting provides twice as much MP as Invocations or Evocations. Depending on your character, though, this may not be a concern.

A typical character starts with 0-7 MP (e.g. 0 for a Minotaur Fighter, 6 for Deep Elf Conjurer, 7 for Deep Elf Wizard) and eventually grows to many times that (30-40 for a level 20 Mummy Necromancer, or 50-60 when using extra items).

Strategy

MP is a very important stat for spellcasters. Early or mid game rings of magical power are extremely useful, since MP costs are low and your base mana pool is small. However, as your MP hits around the 40+ mark, the efficiency of this stat gets drastically lower. Perhaps the only source of MP that you should use at this point is a staff of magical power, but even that could be replaced by an enhancer staff if you find one appropriate for you.

Methods of MP restoration:

Convenient

• Killing monsters while worshipping Vehumet. Monsters give MP in proportion to their HD. Very nice since you'll be able to kill more with the MP you got, which you can use to kill more etc.
• The Shining One also offers MP on kills, but that only applies to unholy creatures (demons, undead, and evil).
• Channeling the Staff of Wucad Mu. The MP restoration is fantastic, if you can deal with the side effects afterwards. Being an artifact though, it is quite rare.
• Drinking a potion of magic. They are rare and far between but they don't fail to give you a shot of MP.
• Biting an enemy as a Vine Stalker.
• Casting sublimation of blood, which restores your MP at the cost of your own health. (Remember to save 2 MP for this!)
• Being a demonspawn can grant you access to the spirit shield mutation series, which will grant you improved MP regeneration, especially when you are low on MP (at the cost of your health regeneration), or can grant you the powered by pain mutation which could restore some MP when you take damage. Or you could get both.
• Wearing an Amulet of magic regeneration.

Less convenient

• Channeling Sif Muna's power. The MP restoration is not fantastic, and the hunger cost is considerable, but its success rate is excellent and there are no side effects! This ability is much more useful in battle if you have summons or can disable your foes for a few turns.
• Channeling a staff of energy. The success rate is dismal without high investment in evocations but at least you can swap into it and spam it for faster recovery after a battle.
• A crystal ball of energy gives you back some MP, but comes with its own hard risks. See its page for details.
• Following Jiyva lets you sometimes gain MP when a jelly eats something on the level (chance depends on piety). It is fairly random unless you actively feed your jellies however.
• Waiting. Your MP will come back on its own after a while. Having higher MP will grant you proportionately improved mana regeneration.

Formula

• Highest Skill = max(Spellcasting, Invocations/2, Evocations/2)
• MP = Scale*(min(XL, 23) + Highest Skill + min(8, Highest Skill, XL)/2) + Species Modifier
• Sources of MP scaling:
  • High MP mutation: +10% per level
  • Low MP mutation: -10% per level
  • Elyvilon's Divine vigour: +50%
• Sources of flat MP bonuses (applied after scaling):
  • Rings of magical power: +9 MP
  • Maxwell's etheric cage: +4 MP
  • Staves of power: +15 MP
• Wielding a weapon of antimagic divides MP by 3. This is applied after all other modifiers.

MP modifiers

From Dungeon Crawl Stone Soup in-game documentation:

At	Ba	Co	DE	Dg	Ds	Dj	Dr	Fe	Fo	Gr	Gh	Gn	Hu	Ko	Mf	Mi	MD	Mu	Na	Op	On	Sp	Te	Tr	Vp	VS
0	0	0	2	2	0	N/A	0	1	0	0	0	0	0	0	0	-1	0	0	0	0	0	1	1	-1	0	1

Demigods additionally start with the High MP mutation.

History

0.17 simplified MP calculations. The base formula was:

XL + Permanent MP + (XL*Species modifier + 1)/3 + (XL*Species modifier + 1)/3 + max(Spellcasting*XL*3/14 + Spellcasting, Invocations*XL/6.5 + Invocations/3, Evocations*XL/6)

Then a stepdown function was applied and MP was capped at 50. Species aptitudes used to be multiplicative, but are now additive.

Before 0.14, the formula was:

Unscaled MP = XL + Permanent MP + (XL*Species modifier + 1)/3 +
max(Spellcasting*XL/4, Invocations*XL/6, Evocations*XL/6)

where Permanent MP was a constant determined by the player's background and species.