Armor training: separate armor penalties from shield use

SRD 5.2.1 · Equipment

At the table

1. Match the worn armor to Light, Medium or Heavy training.
2. Without that training, apply Disadvantage to Strength- or Dexterity-based D20 Tests and prevent spellcasting.
3. For an untrained shield, withhold its AC bonus; do not replace this with the listed armor penalties.

Example decision

A character lacks shield training but is otherwise wearing armor they are trained to use. Does the shield grant its normal AC bonus?

No; the character does not gain the shield’s AC bonus.

The shield clause explicitly removes the AC bonus when training is missing. The separate clause about untrained Light, Medium or Heavy armor governs Strength and Dexterity tests and spellcasting. Check each item against its own clause rather than treating every piece of protective equipment identically.

Watch for this mistake

Do not call the armor penalty Disadvantage on every roll. It is limited to D20 Tests involving Strength or Dexterity. Read the character’s actual training before imposing it.

Ask the table

Which armor category and shield training does this character actually have?

Source rule

Armor training allows you to use armor of a certain category without the following drawbacks. If you wear Light, Medium, or Heavy armor and lack training with it, you have Disadvantage on any D20 Test that involves Strength or Dexterity, and you can’t cast spells. If you use a Shield and lack training with it, you don’t gain its AC bonus. See also “Disadvantage” and “Equipment” (“Armor”).

Source: SRD 5.2.1, 177. Online guide.