The following rules apply to the use of magical Spells and Rituals. Magic items are discussed in their own section. The art of making spells through combining Word of Power is covered in the Epic section.
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.
To cast a spell, you must be able to speak and gesture. For some spells, you must be able to manipulate the material components or focus of the spell. Additionally, you must concentrate to cast a spell.
Casting a spell counts against your daily limit for spells of that spell level, but you can cast the same spell again if you haven't reached your limit.
Table: Concentration Check DCs
|Situation||Concentration Check DC|
|Cast defensively||15 + double spell level|
|Cast by whispering(1)||15 + double spell level|
|Injured while casting||10 + damage dealt + spell level|
|Continuous damage while casting||10 + 1/2 damage dealt + spell level|
|Affected by a non-damaging spell while casting||DC of the spell + spell level|
|Grappled or pinned while casting||10 + grappler's CMA + spell level|
|Vigorous motion while casting||10 + spell level|
|Violent motion while casting||15 + spell level|
|Extremely violent motion while casting||20 + spell level|
|Wind with rain or sleet while casting||5 + spell level|
|Wind with hail and debris while casting||10 + spell level|
|Weather caused by spell||see spell|
|Entangled while casting||15 + spell level|
(1) You must be able to hear your own voice to cast spells, otherwise you risk the failure chance as if deaf.
To cast a spell, you must concentrate. If something interrupts your concentration while you're casting, you must make a concentration check or lose the spell. When you make a concentration check, you roll d20 and add your caster level and the ability score modifier used to determine bonus spells of the same type. You choose which mental ability score (Charisma, Intelligence or Wisdom) you use to cast spells when you first take a level in the Caster class. The more distracting the interruption and the higher the level of the spell you are trying to cast, the higher the DC (see Table: Concentration Check DCs). If you fail the check, you lose the spell just as if you had cast it to no effect.
Injury: If you take damage while trying to cast a spell, you must make a concentration check with a DC equal to 10 + the damage taken + the level of the spell you're casting. If you fail the check, you lose the spell without effect. The interrupting event strikes during spellcasting if it comes between the time you started and the time you complete a spell (for a spell with a casting time of 1 full round or more) or if it comes in response to your casting the spell (such as an attack of opportunity provoked by the spell or a contingent attack, such as a readied action).
If you are taking continuous damage, such as from a fire or pool of acid, half the damage is considered to take place while you are casting a spell. You must make a concentration check with a DC equal to 10 + 1/2 the damage that the continuous source last dealt + the level of the spell you're casting. If the last damage dealt was the last damage that the effect could deal, then the damage is over and does not distract you.
Spell: If you are affected by a spell while attempting to cast a spell of your own, you must make a concentration check or lose the spell you are casting. If the spell affecting you deals damage, the DC is 10 + the damage taken + the level of the spell you're casting.
If the spell interferes with you or distracts you in some other way, the DC is the spell's saving throw DC + the level of the spell you're casting. For a spell with no saving throw, it's the DC that the spell's saving throw would have if a save were allowed (10 + spell level + caster's ability score).
Grappling or Pinned: The only spells you can cast while grappling or pinned are those without somatic components and whose material components (if any) you have in hand. Even so, you must make a concentration check (DC 10 + the grappler's CMA + the level of the spell you're casting) or lose the spell.
Vigorous Motion: If you are riding on a moving mount, taking a bouncy ride in a wagon, on a small boat in rough water, below decks in a storm-tossed ship, or simply being jostled in a similar fashion, you must make a concentration check (DC 10 + the level of the spell you're casting) or lose the spell.
Violent Motion: If you are on a galloping horse, taking a very rough ride in a wagon, on a small boat in rapids or in a storm, on deck in a storm-tossed ship, or being pitched roughly about in a similar fashion, you must make a concentration check (DC 15 + the level of the spell you're casting) or lose the spell. If the motion is extremely violent, such as that caused by an earthquake, the DC is equal to 20 + the level of the spell you're casting.
Violent Weather: You must make a concentration check if you try to cast a spell in violent weather. If you are in a high wind carrying blinding rain or sleet, the DC is 5 + the level of the spell you're casting. If you are in wind-driven hail, dust, or debris, the DC is 10 + the level of the spell you're casting. In either case, you lose the spell if you fail the concentration check. If the weather is caused by a spell, use the rules as described in the spell's description.
Casting Defensively: If you want to cast a spell without provoking any attacks of opportunity, you must make a concentration check (DC 15 + double the level of the spell you're casting) to succeed. You lose the spell if you fail.
Entangled: If you want to cast a spell while entangled in a net or by a tanglefoot bag or while you're affected by a spell with similar effects, you must make a concentration check to cast the spell (DC 15 + the level of the spell you're casting). You lose the spell if you fail.
A spell's power often depends on its caster level, which for spellcasting characters is equal to her caster class level.
You can cast a spell at a lower caster level than normal, but the caster level you choose 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 feat or other special ability provides an adjustment to your caster level, that adjustment applies not only to effects based on caster level (such as range, duration, and damage dealt), 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).
If you ever try to cast a spell in conditions where the characteristics of the spell cannot be made to conform, the casting fails and the spell is wasted.
Spells also fail if your concentration is broken and might fail if you're wearing armour while casting a spell with somatic components.
Once you know which creatures (or objects or areas) are affected, and whether those creatures have made successful saving throws (if any were allowed), you can apply whatever results a spell entails.
Many special spell effects are handled according to the school of the spells in question. Certain other special spell features are found across spell schools.
Attacks: Some spell descriptions refer to attacking. All offensive combat actions, even those that don't damage opponents, are considered attacks. Attempts to channel energy count as attacks if it would harm any creatures in the area. All spells that opponents resist with saving throws, that deal damage, or that otherwise harm or hamper subjects are attacks. Spells that summon monsters or other allies are not attacks because the spells themselves don't harm anyone.
Bonus Types: Usually, a bonus has a type that indicates how the spell grants the bonus. The important aspect of bonus types is that two bonuses of the same type don't generally stack. With the exception of dodge bonuses, most circumstance bonuses, and racial bonuses, only the better bonus of a given type works (see Combining Magical Effects). The same principle applies to penalties—a character taking two or more penalties of the same type applies only the worst one, although most penalties have no type and thus always stack. Bonuses without a type always stack, unless they are from the same source.
Spells or magical effects usually work as described, no matter how many other spells or magical effects happen to be operating in the same area or on the same recipient. Except in special cases, a spell does not affect the way another spell operates. Whenever a spell has a specific effect on other spells, the spell description explains that effect. Several other general rules apply when spells or magical effects operate in the same place:
Stacking Effects: Spells that provide bonuses or penalties on attack rolls, damage rolls, saving throws, and other attributes usually do not stack with themselves. More generally, two bonuses of the same type don't stack even if they come from different spells (or from effects other than spells; see Bonus Types, above).
Different Bonus Types: The bonuses or penalties from two different spells stack if the modifiers are of different types. A bonus that doesn't have a type stacks with any bonus.
Same Effect More than Once in Different Strengths: In cases when two or more identical spells are operating in the same area or on the same target, but at different strengths, only the one with the highest strength applies.
Same Effect with Differing Results: The same spell can sometimes produce varying effects if applied to the same recipient more than once. Usually the last spell in the series trumps the others. None of the previous spells are actually removed or dispelled, but their effects become irrelevant while the final spell in the series lasts.
One Effect Makes Another Irrelevant: Sometimes, one spell can render a later spell irrelevant. Both spells are still active, but one has rendered the other useless in some fashion.
Multiple Mental Control Effects: Sometimes magical effects that establish mental control render each other irrelevant, such as spells that remove the subject's ability to act. Mental controls that don't remove the recipient's ability to act usually do not interfere with each other. If a creature is under the mental control of two or more creatures, it tends to obey each to the best of its ability, and to the extent of the control each effect allows. If the controlled creature receives conflicting orders simultaneously, the competing controllers must make opposed Charisma checks to determine which one the creature obeys.
Spells with Opposite Effects: Spells with opposite effects apply normally, with all bonuses, penalties, or changes accruing in the order that they apply. Some spells negate or counter each other. This is a special effect that is noted in a spell's description.
Instantaneous Effects: Two or more spells with instantaneous durations work cumulatively when they affect the same target.
The description of each spell is presented in a standard format. Each category of information is explained and defined below.
Name: This is the name of the spell.
Level (Domain): This entry lists the level the spell is. Each spell belongs to a domain, which is a group of similar spells, noted in parentheses.
Duration: This line lists the duration of the spell.
Timed Durations: Many durations are measured in rounds, minutes, hours, or other increments. When the time is up, the magic goes away and the spell ends. If a spell's duration is variable, the duration is rolled secretly so the caster doesn't know how long the spell will last.
Instantaneous: The spell energy comes and goes the instant the spell is cast, though the consequences might be long-lasting.
Permanent: The energy remains as long as the effect does. This means the spell is vulnerable to dispelling magic.
Concentration: The spell lasts as long as you concentrate on it. Concentrating to maintain a spell is a standard action that does not provoke attacks of opportunity. Anything that could break your concentration when casting a spell can also break your concentration while you're maintaining one, causing the spell to end. See concentration.
You can't cast a spell while concentrating on another one. Some spells last for a short time after you cease concentrating.
Subjects, Effects, and Areas: If the spell affects creatures directly, the result travels with the subjects for the spell's duration. If the spell creates an effect, the effect lasts for the duration. The effect might move or remain still. Such an effect can be destroyed prior to when its duration ends. If the spell affects an area, then the spell stays with that area for its duration.
Creatures become subject to the spell when they enter the area and are no longer subject to it when they leave.
Touch Spells and Holding the Charge: In most cases, if you don't discharge a touch spell on the round you cast it, you can hold the charge (postpone the discharge of the spell) indefinitely. You can make touch attacks round after round until the spell is discharged. If you cast another spell, the touch spell dissipates.
Some touch spells allow you to touch multiple targets as part of the spell. You can't hold the charge of such a spell; you must touch all targets of the spell in the same round that you finish casting the spell.
Discharge: Occasionally an effect lasts for a set duration or until triggered or discharged.
(D) Dismissible: If the duration line ends with “(D),” you can dismiss the effect at will. You must be within range of the spell's effect and must speak words of dismissal, which are usually a modified form of the spell's verbal component. If the spell has no verbal component, you can dismiss the effect with a gesture. Dismissing a spell is a standard action that does not provoke attacks of opportunity.
A spell that depends on concentration is dismissible by its very nature, and dismissing it does not take an action, since all you have to do to end the spell is to stop concentrating on your turn.
Saving Throw: If the effect allows a saving throw, it is noted here along with the effect of a successful save.
Negates: The spell has no effect on a subject that makes a successful saving throw.
Partial: The spell has an effect on its subject. A successful saving throw means that some lesser effect occurs.
Half: The spell deals damage, and a successful saving throw halves the damage taken (round down).
None: No saving throw is allowed.
Disbelief: A successful save lets the subject ignore the spell's effect.
(object): The spell can be cast on objects, which receive saving throws only if they are magical or if they are attended (held, worn, grasped, or the like) by a creature resisting the spell, in which case the object uses the creature's saving throw bonus unless its own bonus is greater. This notation does not mean that a spell can be cast only on objects. Some spells of this sort can be cast on creatures or objects. A magic item's saving throw bonuses are each equal to 2 + 1/2 the item's caster level.
(harmless): The spell is usually beneficial, not harmful, but a targeted creature can attempt a saving throw if it desires.
Saving Throw Difficulty Class: A saving throw against your spell has a DC of 10 + the level of the spell + your bonus for the relevant ability. A spell's level can vary depending on your class. Always use the spell level applicable to your class.
Succeeding on a Saving Throw: A creature that successfully saves against a spell that has no obvious physical effects feels a hostile force or a tingle, but cannot deduce the exact nature of the attack. Likewise, if a creature's saving throw succeeds against a targeted spell, you sense that the spell has failed. You do not sense when creatures succeed on saves against effect and area spells.
Voluntarily Giving up a Saving Throw: A creature can voluntarily forego a saving throw and willingly accept a spell's result. Even a character with a special resistance to magic can suppress this quality.
Table: Items Affected by Magical Attacks
|3rd||Magic helmet, hat, or headband|
|4th||Item in hand (including weapon, wand, or the like)|
|6th||Stowed or sheathed weapon|
|9th||Magic jewellery (including rings)|
*In order of most likely to least likely to be affected.
Items Surviving after a Saving Throw: Unless the descriptive text for the spell specifies otherwise, all items carried or worn by a creature are assumed to survive a magical attack. If a creature rolls a natural 1 on its saving throw against the effect, however, an exposed item is harmed (if the attack can harm objects). Refer to Table: Items Affected by Magical Attacks: Items Affected by Magical Attacks. Determine which four objects carried or worn by the creature are most likely to be affected and roll randomly among them. The randomly determined item must make a saving throw against the attack form and take whatever damage the attack dealt.
If the selected item is not carried or worn and is not magical, it does not get a saving throw. It simply is dealt the appropriate damage.
Spell Resistance: Certain creatures are supernaturally resistant to magic. If the spell allows spell resistance, it is noted here. If your spell is being resisted by a creature with spell resistance, you must make a caster level check (1d20 + caster level) at least equal to the creature's spell resistance for the spell to affect that creature. The defender's spell resistance is like a Defence check against magical attacks. Include any adjustments to your caster level to this caster level check.
The Spell Resistance entry and the descriptive text of an spell description tell you whether spell resistance protects creatures from the spell. In many cases, spell resistance applies only when a resistant creature is targeted by the spell, not when a resistant creature encounters a spell that is already in place.
The terms “object” and “harmless” mean the same thing for spell resistance as they do for saving throws. A creature with spell resistance must voluntarily lower the resistance (a standard action) in order to be affected by such spells without forcing the caster to make a caster level check.
Target: A spell's range indicates how far from you it can reach, as defined in the range entry of the spell description. A spell's range is the maximum distance from you that the spell's effect can occur, as well as the maximum distance at which you can designate the spell's point of origin. If any portion of the spell's area would extend beyond this range, that area is wasted. Standard ranges include the following.
Personal: The spell affects only you.
Touch: You must touch a creature or object to affect it. A touch spell that deals damage can score a critical hit just as a weapon can. A touch spell threatens a critical hit on a natural roll of 20 and deals double damage on a successful critical hit. Some touch spells allow you to touch multiple targets. You can touch up to 6 willing targets as part of the casting, but all targets of the spell must be touched in the same round that you finish casting the spell. If the spell allows you to touch targets over multiple rounds, touching 6 creatures is a full-round action.
Close: The spell reaches as far as 25 feet away from you. The maximum range increases by 5 feet for every two full caster levels.
Medium: The spell reaches as far as 100 feet + 10 feet per caster level.
Long: The spell reaches as far as 400 feet + 40 feet per caster level.
Unlimited: The spell reaches anywhere on the same plane of existence.
Range Expressed in Feet: Some spells have no standard range category, just a range expressed in feet.
Description: This paragraph describes the effects of the spell.
You must make choices about whom a spell is to affect or where an effect is to originate, depending on a spell's type. The next entry in a spell description defines the spell's target (or targets), its effect, or its area, as appropriate.
Target or Targets: Some spells have a target or targets. You cast these spells on creatures or objects, as defined by the spell itself. You must be able to see or touch the target, and you must specifically choose that target. You do not have to select your target until you finish casting the spell.
If the target of a spell is yourself (the Target line of the spell description includes “You”), you do not receive a saving throw, and spell resistance does not apply. The saving throw and spell resistance lines are omitted from such spells.
Some spells restrict you to willing targets only. Declaring yourself as a willing target is something that can be done at any time (even if you're flat-footed or it isn't your turn). Unconscious creatures are automatically considered willing, but a character who is conscious but immobile or helpless (such as one who is bound, cowering, grappling, paralyzed, pinned, or stunned) is not automatically willing.
Some spells allow you to redirect the effect to new targets or areas after you cast the spell. Redirecting a spell is a move action that does not provoke attacks of opportunity.
Effect: Some spells create or summon things rather than affecting things that are already present.
You must designate the location where these things are to appear, either by seeing it or defining it. Range determines how far away an effect can appear, but if the effect is mobile, after it appears it can move regardless of the spell's range.
Ray: Some effects are rays. You aim a ray as if using a ranged weapon, though typically you make a ranged touch attack rather than a normal ranged attack. As with a ranged weapon, you can fire into the dark or at an invisible creature and hope you hit something. You don't have to see the creature you're trying to hit, as you do with a targeted spell. Intervening creatures and obstacles, however, can block your line of sight or provide cover for the creature at which you're aiming.
If a ray spell has a duration, it's the duration of the effect that the ray causes, not the length of time the ray itself persists.
If a ray spell deals damage, you can score a critical hit just as if it were a weapon. A ray spell threatens a critical hit on a natural roll of 20 and deals double damage on a successful critical hit.
Spread: Some effects, notably clouds and fogs, spread out from a point of origin, which must be a grid intersection. The effect can extend around corners and into areas that you can't see. Figure distance by actual distance travelled, taking into account turns the spell effect takes. When determining distance for spread effects, count around walls, not through them. As with movement, do not trace diagonals across corners. You must designate the point of origin for such an effect, but you need not have line of effect (see below) to all portions of the effect.
Area: Some spells affect an area. Sometimes a spell description specifies a specially defined area, but usually an area falls into one of the categories defined below.
Regardless of the shape of the area, you select the point where the spell originates, but otherwise you don't control which creatures or objects the spell affects. The point of origin of a spell is always a grid intersection. When determining whether a given creature is within the area of a spell, count out the distance from the point of origin in squares just as you do when moving a character or when determining the range for a ranged attack. The only difference is that instead of counting from the centre of one square to the centre of the next, you count from intersection to intersection.
You can count diagonally across a square, but remember that every second diagonal counts as 2 squares of distance. If the far edge of a square is within the spell's area, anything within that square is within the spell's area. If the spell's area only touches the near edge of a square, however, anything within that square is unaffected by the spell.
Burst, Emanation, or Spread: Most spells that affect an area function as a burst, an emanation, or a spread. In each case, you select the spell's point of origin and measure its effect from that point.
A burst spell affects whatever it catches in its area, including creatures that you can't see. It can't affect creatures with total cover from its point of origin (in other words, its effects don't extend around corners). The default shape for a burst effect is a sphere, but some burst spells are specifically described as cone-shaped. A burst's area defines how far from the point of origin the spell's effect extends.
An emanation spell functions like a burst spell, except that the effect continues to radiate from the point of origin for the duration of the spell. Most emanations are cones or spheres.
A spread spell extends out like a burst but can turn corners. You select the point of origin, and the spell spreads out a given distance in all directions. Figure the area the spell effect fills by taking into account any turns the spell effect takes.
Cone, Cylinder, Line, or Sphere: Most spells that affect an area have a particular shape.
A cone-shaped spell shoots away from you in a quarter-circle in the direction you designate. It starts from any corner of your square and widens out as it goes. Most cones are either bursts or emanations (see above), and thus won't go around corners.
When casting a cylinder-shaped spell, you select the spell's point of origin. This point is the centre of a horizontal circle, and the spell shoots down from the circle, filling a cylinder. A cylinder-shaped spell ignores any obstructions within its area.
A line-shaped spell shoots away from you in a line in the direction you designate. It starts from any corner of your square and extends to the limit of its range or until it strikes a barrier that blocks line of effect. A line-shaped spell affects all creatures in squares through which the line passes.
A sphere-shaped spell expands from its point of origin to fill a spherical area. Spheres may be bursts, emanations, or spreads.
Creatures: A spell with this kind of area affects creatures directly (like a targeted spell), but it affects all creatures in an area of some kind rather than individual creatures you select. The area might be a spherical burst, a cone-shaped burst, or some other shape.
Many spells affect “living creatures,” which means all creatures other than constructs and undead. Creatures in the spell's area that are not of the appropriate type do not count against the creatures affected.
Objects: A spell with this kind of area affects objects within an area you select (as Creatures, but affecting objects instead).
Other: A spell can have a unique area, as defined in its description.
(S) Shapeable: If an area or effect entry ends with “(S),” you can shape the spell. A shaped effect or area can have no dimension smaller than 10 feet. Many effects or areas are given as cubes to make it easy to model irregular shapes. Three-dimensional volumes are most often needed to define aerial or underwater effects and areas.
Line of Effect: A line of effect is a straight, unblocked path that indicates what a spell can affect. A line of effect is cancelled by a solid barrier. It's like line of sight for ranged weapons, except that it's not blocked by fog, darkness, and other factors that limit normal sight.
You must have a clear line of effect to any target that you cast a spell on or to any space in which you wish to create an effect. You must have a clear line of effect to the point of origin of any spell you cast.
A burst, cone, cylinder, or emanation spell affects only an area, creature, or object to which it has line of effect from its origin (a spherical burst's centre point, a cone-shaped burst's starting point, a cylinder's circle, or an emanation's point of origin).
An otherwise solid barrier with a hole of at least 1 square foot through it does not block a spell's line of effect. Such an opening means that the 5-foot length of wall containing the hole is no longer considered a barrier for purposes of a spell's line of effect.
Daily Readying of Spells: Each day, Casters must focus their minds on the task of casting their spells. A Caster needs 8 hours of rest, after which she spends 15 minutes concentrating. During this period, the Caster readies her mind to cast her daily allotment of spells. Without such a period to refresh herself, the character does not regain the spell slots she used up the day before.
Recent Casting Limit: Any spells cast within the last 8 hours count against the Caster's daily limit.
Adding Spells to a Caster's Repertoire: A Caster gains spells each time she attains a new level in her class and never gains spells any other way. When your Caster gains a new level, consult the Caster class table to learn how many spells from the appropriate spell list she now knows.
A number of feats grant the use of special abilities, many of which function like spells. Some creatures naturally have special abilities because of their race. The following rules govern both feats and racial abilities.
Spell-Like Abilities: Usually, a spell-like ability works just like the spell of that name. A spell-like ability has no verbal, somatic, or material component, nor does it require a focus. The user activates it mentally. Armour never affects a spell-like ability's use, even if the ability resembles an arcane spell with a somatic component.
A spell-like ability has a casting time of 1 standard action unless noted otherwise in the ability or spell description. In all other ways, a spell-like ability functions just like a spell.
Spell-like abilities are subject to spell resistance and dispel magic. They do not function in areas where magic is suppressed or negated. Spell-like abilities cannot be used to counterspell, nor can they be counterspelled.
Some creatures actually cast arcane spells as sorcerers do, using components when required. Some creatures have both spell-like abilities and actual spellcasting power.
Supernatural Abilities: These can't be disrupted in combat and generally don't provoke attacks of opportunity. They aren't subject to spell resistance, counterspells, or dispel magic, and don't function in antimagic areas.
Extraordinary Abilities: These abilities cannot be disrupted in combat, as spells can, and they generally do not provoke attacks of opportunity. Effects or areas that negate or disrupt magic have no effect on extraordinary abilities. They are not subject to dispelling, and they function normally in an antimagic field. Indeed, extraordinary abilities do not qualify as magical, though they may break the laws of physics.
Natural Abilities: This category includes abilities a creature has because of its physical nature. Natural abilities are those not otherwise designated as extraordinary, supernatural, or spell-like.
«PLACEHOLDER - SEE Words of Power Rituals»
Dedicated scholars and priests, as well as some Casters, learn the ways of ritual magic. By performing prescribed actions, speaking arcane words and following the directions of the written ritual, magic effects can be achieved without the raw power of spells. To outsiders, the distinction is fine, but ritualists and casters know the subtle difference.
A ritual is performed from a written text, either in a ritual book (a permanent record of the ritual) or from a scroll (which is consumed in the performance of the ritual). Ritual scrolls may be copied into a ritual book with the same effort required to perform the ritual: either the expenditure of a spell slot, or the full performance of the ritual. Rituals are performed rather than cast like spells, so as well as requiring concentration, a Use Magic Device skill check is usually made (unless a spell slot is sacrificed to provide the guarantee of success).
Aside from requiring power (in the form of expended spell energy or expended ritual materials), some rituals require a sacrifice of a material component or a focus. These must be present on hand to the ritualist through the entire performance. Any material component is used up at the end of the ritual. A focus is not used up and may be used again for another performance.
Using your ritual book, or a ritual scroll, you may perform a ritual with magical effects as listed in the ritual description. You must concentrate to perform a ritual: if your concentration is broken during the ritual, the ritual fails and any materials used are consumed and lost. The concentration check is made in the same manner as for spells, and the same DCs apply.
You may expend a spell slot of equal level to the ritual if you have one available, in which case the ritual automatically succeeds and takes only the minimum listed time to perform.
If you have no spells slots of the appropriate level, or choose not to use one, you must succeed in a number of Use Magic Device checks (DC 15 + 2 x ritual level) equal to the level of the ritual, each taking 1 hour, and using 25gp of ritual materials (incense, libations of oil, animal sacrifice or similar). Performing a ritual in this manner takes at least 1 hour. 0 level rituals count as 1/2 a level (DC 16, requiring 1 successful check), Epic rituals count as 5th level (DC 25, requiring 5 successful checks). If any of these checks fail, the ritual materials are consumed, but ritual is not lost: the ritualist may continue, provide more ritual materials, and another check may be made in one hour.
As with other skill checks, the ritualist may be assisted by anyone with ranks in Use Magic Device, using the Aid Another action.
If you have Caster class levels, you simply use these to represent your caster level when the ritual description requires is (for example, some durations are dependent on caster level). If you have no Caster class levels, but have the Ritual Magic feat, then your caster level counts as half your total level (at least one).