crawl-common 2:0.21.1-1 / usr / share / crawl / docs / develop / spells.txt

Spell schools
=============

With recent changes to the spell schools, it has become important to
specifically state what is and what is not included under the purview of a
specific school.

This document is essentially vague in order to distill the complete "schoolness"
of the individual schools. It uses specific examples of things that would and
would not be included in a school to explain them.

Of course, as Crawl is fluid, so too are the schools fluid: these are not
specific rules inasmuch as they are guidelines. They will be subject to change,
to argument, to discussion and to disagreements.

In summary: we should paint the bike shed green.

None
====

This is a school reserved for spells with no type.

Conjuration
===========

Conjuration is the act of producing something from nothing.

This includes: creation of projectiles (such as Magic Dart), creation of clouds
(such as Mephitic Cloud), and all instances where something is created from
nothing.

This does not include: transmutations (creating something from something else),
summoning (calling in a pre-existing entity), or spells that are specifically
flavoured so as not to be conjurations. (Whatever those are.)

Conjurations are always damage spells; this extends to the creation of
damaging clouds, but anything more indirect is probably out of the school's
scope.

Hexes
=====

Hexes are spells that affect things and monsters (usually negatively). They
cannot do direct damage nor change fundamental state of anything without
another spell school being involved.

If we had spells that bestow a curse on someone or something, make an item
zap anyone who touched it, enlarge a person or give him a nasty itch, they
would be all hexes. Beguiling and illusions also belong here.

This includes: slowing monsters, paralysing monsters, confusing monsters, etc.

Charms
======

Charms are things that positively affect yourself, having amulet ("charm")-like
effects. They all have a lasting effect, and never affect anyone else except
for direct contact with the warded person (RoF, RMsl, ...).

These are wards or enhancements: give you a resistance, let you move or heal
faster, let you have more control on magic affecting you, make you stronger.

This includes: hasting yourself, spells to repel attacks, etc.

Fire
====

All spells involving fire of any kind.

This includes: conjurations of fire, spells involving heat or burning, etc.
Fire cannot produce non-damage, 'utility' effects without other schools being
involved, but can be used to create flame clouds or, potentially, temporary
lava.

Ice
===

All spells involving ice or cold of any kind.

This includes: conjurations of ice, spells involving freezing or cooling, etc.
Ice is a versatile element, and can produce direct damage (with a focus on
damage that partially ignores elemental resistances), freezing clouds, utility
effects (especially defensive ones), and debilitating effects, especially
slowing.

Transmutation
=============

Transmutation is the act of converting one thing into another thing. This may
also include the fundamental change of the state of a thing, whether or not that
change is permanent.

This includes: converting your body into another form, polymorphing creatures
into other creatures, converting rock into liquid, and the creation and
manipulation of mutagenic radiation.

Caveat: there was a trend towards including the Transmutation spell in most
schools relating to Earth. Think very carefully about whether a new Earth spell
belongs in this school before adding it.

Necromancy
==========

Necromancy is primarily the act of talking to the dead for divinatory purposes.
In the Crawl mythos, it is any type of magic that involves death, undeath,
corpses, causing unholy pain, or the act of draining life force, and most
unholiness in general.

This includes: all spells relating to the raising of corpses as undead, be they
as zombies, spectral creatures, simulacra or skeletons; bolts of draining, pain,
vampiric draining, revivification; etc.

This specifically includes: regeneration. The flavour of this spell is that your
wounds are reanimated by necromantic magic. This act is considered unholy by its
very nature.

This specifically excludes: Fedhas' ability to hasten the decay of corpses.
This is a) a divine act, though not specifically a holy one, and b) flavoured as
though the natural process of decay has been quickened, rather than the corpse
being unnaturally decayed.

Summoning
=========

Summoning involves the magical transportation of creatures from another place to
here. This is specifically not the creation of these beings, as when they are
"killed" they return to where they came from, and if the summoning finishes
while they are still alive, they also return to where they came from.

This "place" is undefined as far as Crawl's mythos is concerned. Indeed, it
varies from spell to spell: some of them specifically summon creatures from the
Hells (such as demons and devils: this is historically accurate as far as
Demonology and the summoning of devils is concerned), or from the Abyss (as per
the flavour of Summon Horrible Things), whereas others are non-specific.

This specifically includes: all monsters that are not considered to be "here",
that is, all monsters that have been brought here from another place.

This specifically excludes: monsters that have been transmuted from something.
In these instances the monsters are either short-formed (ie, they revert back to
their previous form, or to nothing), or short-lived (ie, they die shortly after
being created).

All summoned monsters are Abjurable; all transmuted monsters are not.

Note that Summoning is not limited to the summoning of monsters; it can be used
to summon surrounding terrain as well, as with Summon Forest.

Translocation
=============

This is the act of moving something through magical means, sometimes via
portals.

This includes teleportation, the indirect movement from one place to another, and
blinking, which is the same but for shorter distances. It also includes the
creation of portals of any description, such as Malign Gateway (the creation of a
portal to an undefined location) or Portal Projectile (the creation of a portal
to a specific, nearby location).

This also specifically includes spells which cause things to be continuously
moved from one location to another, such as Apportation or Gell's Gravitas.

Poison
======

All spells involving poison of any kind.

Poison is specifically intended to be relatively strong early on and to
fall off later, to create a distinct experience from other spell schools.

This specifically excludes: acid and acid-related spells.

Earth
=====

All spells involving the earth specifically as an element.

This includes: spells that affect the earth or earth-based substances.

The school is mainly focused on damaging spells, especially single-target
spells; multi-target damage spells tend to be more limited in number and in
targeting applicability than those provided by other elemental schools. It
also uses 'fragment' damage, which is heavily affected by AC.

Other effects provided include manipulation of solid terrain for utility
(Passwall, Leda's), and petrification (Statue Form, Petrify).

Air
===

All spells involving the air specifically as an element.

This includes: flying, the ability to repel missiles (presumably by
manipulating air flow, though not currently flavoured as such), the creation
of clouds (in combination with the relevant element and the school of
Conjurations), etc.

This also specifically includes electricity and electrical forces. Electrical
effects are either unpredictable and dangerous to the caster (Static Discharge,
Chain Lightning, Conjure Ball Lightning), or inaccurate (Zap, Lightning Bolt).
They either partially or entirely ignore AC, and, in the case of beam spells,
can be bounced off walls for trick shots. Single-target effects are not and
probably should not be offered; Air's only access to precise single-target
damage is Airstrike, which is extremely situational.

Holy
====

These spells specifically involve holy acts, usually defined within the scope of
the "good" Gods (Zin, Elyvilon, The Shining One). These spells are currently
only available as monster spells.