Spellcasting

D&D 2024 rule: Spellcasting. Source: Xanathar's Guide to Everything. rule type Optional This section expands on the spellcasting rules presented in the Player's Handbook and the Dungeon Master's Guide, providing clarifications and new options. Perceiving a Caster at Work Many spells create obvious effects: explosions of fire, walls of ice, teleportation, and the like. Other spells, such as charm person, display no visible, audible, or otherwise perceptible sign of their effects, and could easily go unnoticed by someone unaffected by them. As noted in the Player's Handbook, you normally don't know that a spell has been cast unless the spell produces a noticeable effect. But what about the act of casting a spell? Is it possible for someone to perceive that a spell is being cast in their presence? To be perceptible, the casting of a spell must involve a verbal, somatic, or material component. The form of a material component doesn't matter for the purposes of perception, whether it's an object specified in the spell's description, a component pouch, or a spellcasting focus. If the need for a spell's components has been removed by a special ability, such as the sorcerer's Subtle Spell feature or the Innate Spellcasting trait possessed by many creatures, the casting of the spell is imperceptible. If an imperceptible casting produces a perceptible effect, it's normally impossible to determine who cast the spell in the absence of other evidence. Identifying a Spell Sometimes a character wants to identify a spell that someone else is casting or that was already cast. To do so, a character can use their reaction to identify a spell as it's being cast, or they can use an action on their turn to identify a spell by its effect after it is cast. If the character perceived the casting, the spell's effect, or both, the character can make an Intelligence (Arcana) check with their reaction or action. The DC equals 15 + the spell's level. If the spell is cast as a class spell and...