5e SRD >Spells >

Barkskin

2nd-level transmutation

Casting Time:1 action
Range:Touch
Components:V, S, M (a handful of oak bark)
Duration:Concentration, up to 1 hour

You touch a willing creature. Until the spell ends, the target’s skin has a rough, bark-like appearance, and the target’s AC can’t be less than 16, regardless of what kind of armor it is wearing.