Spell components were the fundamental aspects required to cast most Spells. They were generally divided into three categories: material, verbal, and somatic. Nearly all spells required at least one of these components to be successfully cast.
A material component consisted of one or more physical objects or substances. Depending on the spell, once it was cast, the material component was annihilated. However, a spellcaster could often use a Spellcasting Focus to substitute for most components, which would not be consumed by the spell. Valuable or rare material components often had to be stored separately and could not be replaced by a focus.
A verbal component required the caster to complete a spoken incantation in a clear, powerful voice. Being gagged or magically silenced prevent one from casting such a spell.
A somatic component required the caster to make a motion to cast the spell. If the caster was unable to make the correct motion, the spell could not be cast. Wearing armor or using a shield typically interfered with the somatic components of arcane spells, creating a risk of spell failure, though some disciplines specifically trained to navigate these limitations.