D&D 5E Casting with shield without proficiency

[Rya.Reisender]

Is it possible to cast with a shield when you are not proficient with it? The rules for "Casting in armor" only refer to armor hindering you but shields are usually not included in the sections that talk about armor.

 

[Z. H. Darkstar]

Shields are listed in the Armor table, therefore shields are armor. If you're not proficient, you can't cast in it.

 

[pukunui]

Shields are listed in the Armor table, therefore shields are armor. If you're not proficient, you can't cast in it.

This. Shields count as armor.