# Armor Training *Source: Player's Handbook (2024) p. 361. Available in the <span title='Systems Reference Document (5.2)'>SRD</span> and the Free Rules (2024)* 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](Mechanics/CLI/rules/variant-rules/disadvantage-xphb.md) on any [D20 Test](Mechanics/CLI/rules/variant-rules/d20-test-xphb.md) that involves Strength or Dexterity, and you can't cast spells. If you use a [Shield](Mechanics/CLI/items/shield-xphb.md) and lack training with it, you don't gain its AC bonus.