Spellcasting characters and creatures need not prepare their spells for use ahead of time. They either have access to sufficient spell points to cast a spell, or they do not. A spell is cast when a spellcasting character pays its spell point cost. Some magical abilities spell-like or supernatural abilities have a cost of 0 points. They do not expend points from a limited source, but they still require a source of spell points to be cast.
Magic has one fundamental rule. This most fundamental rule of magic is as follows:
The maximum number of spell points you can spend on a spell is equal to your caster level.
Spell points and caster levels are explained in detail below.
The variables of a spell’s effect often depend on its caster level, which is (usually) equal to your spellcasting class level. A spell that can be augmented for additional effect is also limited by your caster level (you can’t spend more spell points on a spell than your caster level). See Augment, below. You can cast a spell at a lower caster level than normal, but the caster level must be high enough for you to cast the spell in question, and all level-dependent features must be based on the same caster level. In the event that a class feature or other special ability provides an adjustment to your caster level, this adjustment applies not only to all effects based on caster level (such as range, duration, and augmentation potential) but also to your caster level check to overcome your target’s spell resistance and to the caster level used in dispel checks (both the dispel check and the DC of the check).
Spellcasting characters and magical creatures cast spells. Whether they cost spell points when cast by a spellcasting character, or are cast as spell-like abilities, spells’ effects remain the same.
Choosing a Spell
First you must choose which spell to cast. You can select any spell you know, provided you are capable of casting spells of that level or higher.
Choose the parameters
Before casting the spell, you must choose targets, the amount of spell points you are going to draw into it, and so on.
To cast a spell, you must concentrate. If something threatens to interrupt your concentration while you’re casting a spell, you must succeed on a Concentration check or spell fails. Any spell points that would have been expended by the spell, are still expended if the spell fails. The more distracting the interruption and the higher the level of the spell that you are trying to cast, the higher the DC. (Higher-level spells require more mental effort.)
Armor and Spells
If an armor or shield has a Armor Check Penalty, it inhibits movement, and may cause spells to fail. The caster must make a Concentration check with a DC of 5 + negative Armor Check Penalty + the spell’s Spell Point Cost. So a mage wearing Scale Mail (ACP -4), casting a spell with a spell point cost of 3, would have to make a Concentration check with a DC of (5 + 4 + 3) 12.
If you try to cast a spell in conditions where the characteristics of the spell (range, area, and so on) cannot be made to conform, the spell fails and any expended spell points are wasted. Spells also fail if your concentration is broken (see Concentration, above).
Resolve the results of the spell, dealing damage, imposing effects, and so on.
Spell Point Sources
Spell points generally come from two separate sources: Magical Auras and Magical Reservoirs. A caster can only draw spell points from one source, a single Magical Aura or a single Magical Reservoir.
Magical auras provide a constant source of spell points. By gaining Magical Focus (see below), a caster taps into this aura, and can cast any spell with a cost up to the aura’s rating.
Some locations have a rating of ½. In these locations, using a spell, spell-like or supernatural effect with a spell point cost of 0 expends your Magical Focus, unless you have access to another source.
In locations without an aura, even no magic can be used, unless you have access to another source.
Magical reservoirs are spell point containers that can contain a set amount of spell points which can be used for spell-casting.
When a caster casts a spell using a reservoir, the spell point cost is subtracted from the number of spell points in the reservoir.
The most common type of magical reservoirs are Thaumic Crystals.
When in an area with a Thaumic Aura, a caster can drain spell points from the background and pour them into an undamaged Thaumic Crystal. A number of spell points equal to twice the aura rating can be poured into the crystal for every minute that the caster spends doing so, up to a maximum of the crystal’s rating.
When drawing from a Thaumic Crystal, in addition to stored spell points, a caster can draw an additional amount of spell points equal to the crystals rating. However drawing any of these additional spell-points cracks the crystal. No more spell points can be drained from the crystal, and any spell points poured into the crystal dissipates immediately.
Gaining Magical Focus
If you have access to a source of rating ½ or more you can meditate to attempt to become magically focused. The DC to become magically focused is 20. Meditating is a full-round action that provokes attacks of opportunity. Once you are magically focused, you remain focused until you expend your focus, become unconscious, or go to sleep (or enter a meditative trance, in the case of elves), or until you don’t have access to any magical sources.
When you are magically focused, you can expend your focus on any single Concentration check you make thereafter. When you expend your focus in this manner, your Concentration check is treated as if you rolled a 15.
You can also expend your focus to gain the benefit of a magical feat or effect – many magical effects are activated in this way.
Magical creatures can create magical effects without having levels in a spellcasting class (although they can take a spellcasting class to further enhance their abilities); such creatures have the magical subtype.
Characters using Wands and other magical items can also create magical effects.
The casting of spells by creatures without a spellcasting class (creatures with the magical subtype, also simply called magical creatures) is considered a spelllike ability (Sp).
Usually, a magical creature’s spell-like ability works just like the spell of that name. A few spelllike abilities are unique; these are explained in the text where they are described. Spell-like abilities have no verbal or somatic components. The user activates them mentally.
A spell-like ability has a casting time of 1 standard action unless noted otherwise in the ability description. In all other ways, a spell-like ability functions just like a spell, notably including that using a spell-like ability provokes attacks of opportunity and is subject to interruption, and the save DCs of spelllike abilities are calculated as normal (if no key ability modifier for calculating the save DC is given, default to Charisma).
Spell-like abilities are subject to spell resistance and to being dispelled by dispel magic. They do not function in areas where magic is suppressed or negated.
All creatures with spell-like abilities are assigned a caster level, which which indicates how difficult it is to dispel their spell-like effects and determines all leveldependent variables (such as range or duration) the abilities might have (like spellcasters, creatures with spell-like abilities may voluntarily lower their caster level). When a creature uses a spell-like ability, the spell is cast as if the creature had spent a number of spell points equal to its caster level. If the spell has augments, it may choose those if its caster level is sufficient.
Some creatures or items have an inherent magical aura or magical reservoirs, which can be solely used to cast their own spells. If this is not the case, the creature or item still requires a magical source with sufficient spell points to case the spell.
Some creatures have magical abilities that are considered supernatural (Su). Magical feats are also supernatural abilities.
These abilities work in all ways like Spell-like abilities, except they cannot be disrupted in combat, as spells can be, and do not provoke attacks of opportunity (except as noted in their descriptions).