Light: select an eligible object before lighting the scene

SRD 5.2.1 · Spell decisions

Before casting

At the table

1. Touch a Large or smaller object that is not worn or carried by someone else.
2. The object sheds Bright Light for a 20-foot radius, then Dim Light for another 20 feet.
3. An opaque covering blocks the light; casting the spell again ends the earlier casting.

Example decision

A caster wants to use Light on a shield currently carried by an enemy. No additional feature changes the spell. Is that shield an eligible target?

No; it is being carried by someone else.

The source excludes an object being worn or carried by someone else. The shield’s size and proximity do not remove that restriction. Choose an eligible object instead, then apply the bright and dim radii around it. Do not invent a saving-throw workaround that this version of the spell does not provide.

Watch for this mistake

Covering the lit object with opaque material blocks its illumination; it is not the same as a stated ending of the spell. Recasting, however, expressly ends the earlier casting.

Ask the table

Who carries the object, how large is it, and what areas will be bright or dim?

Source spell

Evocation Cantrip (Bard, Cleric, Sorcerer, Wizard) Casting Time: Action Range: Touch Components: V, M (a firefly or phosphorescent moss) Duration: 1 hour You touch one Large or smaller object that isn’t being worn or carried by someone else. Until the spell ends, the object sheds Bright Light in a 20-foot radius and Dim Light for an additional 20 feet. The light can be colored as you like. Covering the object with something opaque blocks the light. The spell ends if you cast it again.

Source: SRD 5.2.1, 144. Online guide.