Page:Dungeons & Dragons System Reference Document.pdf/102

 requires a somatic component, the caster must have free use of at least one hand to perform these gestures.

Casting some spells requires particular objects, specified in parentheses in the component entry. A character can use a component pouch or a spellcasting focus (found in “Equipment”) in place of the components specified for a spell. But if a cost is indicated for a component, a character must have that specific component before he or she can cast the spell.

If a spell states that a material component is consumed by the spell, the caster must provide this component for each casting of the spell.

A spellcaster must have a hand free to access a spell’s material components—or to hold a spellcasting focus—but it can be the same hand that he or she uses to perform somatic components.

A spell’s duration is the length of time the spell persists. A duration can be expressed in rounds, minutes, hours, or even years. Some spells specify that their effects last until the spells are dispelled or destroyed.

Many spells are instantaneous. The spell harms, heals, creates, or alters a creature or an object in a way that can’t be dispelled, because its magic exists only for an instant.

Some spells require you to maintain concentration in order to keep their magic active. If you lose concentration, such a spell ends.

If a spell must be maintained with concentration, that fact appears in its Duration entry, and the spell specifies how long you can concentrate on it. You can end concentration at any time (no action required).

Normal activity, such as moving and attacking, doesn’t interfere with concentration. The following factors can break concentration:
 * Casting another spell that requires concentration. You lose concentration on a spell if you cast another spell that requires concentration. You can’t concentrate on two spells at once.
 * Taking damage. Whenever you take damage while you are concentrating on a spell, you must make a Constitution saving throw to maintain your concentration. The DC equals 10 or half the damage you take, whichever number is higher. If you take damage from multiple sources, such as an arrow and a dragon’s breath, you make a separate saving throw for each source of damage.
 * Being incapacitated or killed. You lose concentration on a spell if you are incapacitated or if you die.

The GM might also decide that certain environmental phenomena, such as a wave crashing over you while you’re on a storm-­‐‑tossed ship, require you to succeed on a DC 10 Constitution saving throw to maintain concentration on a spell.

A typical spell requires you to pick one or more targets to be affected by the spell’s magic. A spell’s description tells you whether the spell targets creatures, objects, or a point of origin for an area of effect (described below).

Unless a spell has a perceptible effect, a creature might not know it was targeted by a spell at all. An effect like crackling lightning is obvious, but a more subtle effect, such as an attempt to read a creature’s thoughts, typically goes unnoticed, unless a spell says otherwise.

To target something, you must have a clear path to it, so it can’t be behind total cover.

If you place an area of effect at a point that you can’t see and an obstruction, such as a wall, is between you and that point, the point of origin comes into being on the near side of that obstruction.

If a spell targets a creature of your choice, you can choose yourself, unless the creature must be hostile or specifically a creature other than you. If you are in the area of effect of a spell you cast, you can target yourself.

Spells such as burning hands and cone of cold cover an area, allowing them to affect multiple creatures at once.

A spell’s description specifies its area of effect, which typically has one of five different shapes: cone, cube, cylinder, line, or sphere. Every area of effect has a point of origin, a location from which the spell’s energy erupts. The rules for each shape System Reference Document 5.1