Spellcasting is the use of magic.
- Verbal component
- Many spells require the caster to speak certain words, or, in the case of a bard, create music, to cast a spell. Being prevented from speaking, such as a gag, or effects that remove sounds, such as certain magical effects, makes it impossible for a caster to cast such a spell. A deafened caster may fail when casting a spell, by misspeaking, which causes the spell to be lost.
- Somatic component
- Many spells require the caster to make a motion to cast the spell. If the caster is unable to make the correct motion, the spell cannot be cast. Wearing armor or using a shield interferes with the somatic components of arcane spells, creating a risk of spell failure. Bards and some other arcane classes can cast spells in light armor without this risk.
- Material components
- Casting a spell often requires that the caster sacrifice some sort of material component. Often, these components are virtually worthless, but some spells, such as spells to reanimate the dead, require material components costing thousands of gold pieces. If a caster is unable to access or use the correct spell component, the spell cannot be cast.
- Magical focus
- Alternatively, casting a spell may require that the caster have access to a holy symbol or other special object, to focus on when casting the spell. This is mostly true for divine spells.