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

With repeated overhauls 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 somewhat intentionally vague in order to distill the overall
identity of the individual schools. It does, however, use 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 particular, this document
may not entirely be kept properly up to date, and reading up on the commit log's
history of given spells and schools is crucial to gather sufficient context.

None
====

This is a school reserved for spells with no type. This is only used for monster
spells, when none of the below schools would fit.

This includes: monsters producing tentacles (as extensions of one's body are
not conjured, summoned, or constructed).

Conjurations
============

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 magical constructs of destruction (such as
Fulminant Prism).

This does not include: transmutations (creating something from something else),
summoning (calling in a pre-existing entity), nor constructs with any degree
of separate agency.

Conjurations are always damage spells; this extends to the creation of
damaging clouds or familiars that extend damaging spells, but anything more
indirect is probably out of the school's scope. The school serves both as an
additional skill cost on casting characters, and as a means to help cross
between elements (or by providing pure conjurations themselves) to deal with
given elemental resists. Spells can deal damage without involving conjurations,
mostly through directly affecting and centring around monsters or terrain
without using projectiles.

Hexes
=====

Hexes are spells that negatively affect entities and their equipment. They
cannot do direct damage nor change the fundamental physical state of anything
without involving another spell school.

This includes: slowing, blinding, confusing, weakening, inducing sleep or
frenzy, animating a foe's held weapon, creating fields of silence, and so on.

Many Hexes have struggled with Willpower scaling somewhat arbitrarily throughout
the game and being dissatisfying to roll unlucky with. Many newer or higher
level Hexes sidestep the issue or check other resists and HD instead. Some work
may be needed here eventually (especially at either ends of spell levels), but
the current pool both provides a variety of useful utility effects and
reasonably enables a stabbing playstyle of offense. New spells and spell
revisions could involve more beguiling or illusions, as well as targetters
beyond the whole screen or a beam for a single victim.

Some debuffs are over in Alchemy as is thematically appropriate for that school-
most of Hexes has fewer limitations of matter and conditions needed to transmute
in comparison, in exchange for checking Willpower, HD, and possibly resists.

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, souls, causing unholy pain, or the act of draining life force.

This includes: all spells caring about the immediate deaths of foes (charges
of Grave Claw, raising zombies and spectres), or the near-death state of foes
(Cigotuvi's Putrefaction targetting, Rimeblight's instant-kill). This also
includes a variety of negative energy effects flavoured around suffering,
usually centred around a given monster's holiness.

Notably, this also includes vampiric draining, revivification, and directly
staving off death. All of these are flavoured as necromantic energy regenerating
one's wounds, and are thus considered unholy by their very nature.

Summonings
==========

Summonings involves the magical transportation of creatures and terrain from
another place to here. This is specifically not the creation or construction of
these beings:  when they are "killed", or if the summoning finishes while they
are still alive, these beings return to wherever they came from.

This "place" is undefined as far as Crawl's mythos is concerned. The Abyss is
the flavour source for Summon Horrible Things, while locations unconnected to
the Dungeon entirely are referred to in Summon Forest and Malign Gateway.

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 conjured from something,
which only act as an extension of a spell's targeting or damage. In these
instances the monsters are short-formed or short-lived (usually meaning, they
die shortly after being created). Additionally, they should avoid non-living
status unless relying on otherworldly themes rather than construct themes, to
avoid overlap with Forgecraft's flavour focus. All summoned monsters are
Abjurable by monster summoners; all conjured, constructed, or transmuted
monsters are not.

Forgecraft
==========

In contrast to Summonings, Forgecraft involves the direct creation of transient,
tangible constructs. Usually, they're set to fire or explode.

Beyond the mechanical flavour of Forgecraft, all spells in the school before the
recurring rule-breaking of level 9 spells are defined by their limitations. Many
constructs can't move (Spike Launcher, Lightning Spire, Hoarfrost Cannonade,
Diamond Sawblades), rely on the caster's position to move (Blazeheart Golem,
Phalanx Beetle), or move automatically (Hellfire Mortar). They may rely on
caster actions (Rending Blade and Battlesphere attacks, Monarch Bomb's
detonation), the caster's own equipment and spells (Awaken Armour, Fortress
Blast, Spellspark Servitor, Platinum Paragon), or limited attacks (Clockwork
Bee, Walking Alembic). Frequently, they may not even have regular attacks
(most cannons, Splinterfrost Barricade), and they share between them a repeated
theme of charging up (Bee, Blade, Alembic, Fortress Blast, Bomb, Paragon).

In exchange for all of these different types of limitations, Forgecraft allies
sit between Summoning and Conjurations in providing physically-present entities
that increasingly deal partially- or fully-irresistible damage across multiple
turns, with relatively predictable behaviours that ignore player commands. They
also have non-living resists, can be rapidly deconstructed if not made directly
of magic (Battlesphere & Rending Blade), and cannot be Abjured.

This also includes a limited number of ways to deal direct damage as long as
they're directly tied to conditions and actions; Kinetic Grapnel mostly assists
a follow-up attack, Fortress Blast gives the non-moving limitation to the
caster, and Nazja's Percussive Tempering can only target one's own constructs.

This specifically excludes: allies who do not have any limitations or
dependencies, and allies that are considered obviously "alive".

Translocations
==============

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

This includes partial or complete movement of the caster's body, usually in
short distances compared to consumables (Blink, Vhi's Electric Charge); the
creation of loose or controlled portals (Malign Gateway, Passage of Golubria);
and moving others entirely, whether short distances (Maxwell's Portable
Piledriver) or far (Teleport Other).

This also includes spells which cause items to be moved from one location to
another, such as Apportation or Dimensional Bullseye.

While some forms of direct damage have been tried for this school in the past,
most of it has become highly reliant on the presence of other schools or sheer
weapon skill. The ability to control movement is already a very broad and potent
space in Crawl (also not easily provided elsewhere) without also providing a
direct means to kill.

Alchemy
=======

Alchemy mixes together two different components: the act of fundamentally
changing matter and magic, plus anything involving poison and chemistry of any
kind.

When paired with other schools, this includes turning rock to liquids, poison to
fire, blood to ice, and the creation and manipulation of mutagenic radiation.

Poison as an effect itself is intended to be relatively strong early on and to
fall off later. While other forms of Alchemy and multi-school spells eventually
provide non-poison damage, they have notable limitations and caveats of player
risk even at higher spell levels, and the overall school still has level
limitations compared to all other schools.

Note: Most of the self-warping spells were moved over to the Shapeshifting
skill, which uses talismans. To keep the identity of both this school and those
talismans clean and separate, keep self-transmutation out of these spells.

Fire
====

All spells involving fire or heat of any kind.

This includes: conjurations of fire, spells involving heat or burning, etc.

Compared to other schools, Fire's damage offers some of the largest and most
controlled area-of-effect spells, but is unfriendly to allies and can still
catch the caster in their own blasts. Fire also cannot produce non-damage,
'utility' effects without other schools being involved, but can be used to
create fiery clouds or temporary lava.

Ice
===

All spells involving ice or cold of any kind.

This includes: conjurations of ice, spells involving freezing or cooling, etc.

Compared to other schools, Ice is a versatile yet diffuse element, with high mp
efficiency in exchange for spells with limited range or aim or movement, and
often a focus on damage being stretched over multiple turns. It can also offer
slowing and sleep effects, boosted against the cold-blooded and blocked by those
cold-resistant.

Air
===

All spells involving the air specifically as an element.

This includes: the creation of clouds (in combination with the relevant element
and the school of Conjurations), the use of unpredictable and cascading electric
effects, as well as sudden swift movement.

Compared to other schools, clouds are prolonged in their damage, while electric
effects involve some danger and strange uncontrolled targeting. In exchange,
Electricity resistance is rare compared to other resists, and all electric
damage ignores half of AC. Single-target effects should be very rare: Air's only
access to precise single-target damage without leaving Air and Conjurations
is Airstrike, which has heavy limitations attached to it.

Earth
=====

All spells involving the earth specifically as an element.

This includes: spells that shape the earth, produce or manipulate earth-based
substances, and petrification.

Compared to other schools, the school is mainly focused on damaging spells with
single projectiles; multi-target damage spells tend to be more limited in number
and in targeting conditions than those provided by other elemental schools.
It also uses 'fragment' damage, which is heavily affected by AC. In exchange,
it provides the most straightforward and direct irresistible spells in the game.

Holy
====

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