[RPG] Are material spell components consumed during casting or during preparation


Next to spells in the PHB spell list are lists of components, some of which are material. When specified, material components are expended:

Arcane Lock
Components: V, S, M (gold dust worth at least 25 gp, which the spell consumes)

What I'm asking is exactly when those components are consumed. Is it when you cast the spell, or when you prepare it?

Best Answer

Components are consumed when casting (if applicable).

The Player's Handbook has this to say on materials when casting spells:

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. (PHB, 203)

Emphasis mine.

Components are consumed when the spell is cast, not when it is prepared.