Suppose a ranger puts barding on their animal companion to boost its AC. Does wearing the armor cause this creature to have disadvantage on its attacks, ability checks, and saving throws? Or does the animal companion ignore the penalties somehow?

According to the Armor rules in the PHB, characters who wear armor without proficiency are penalized on their rolls:

If you wear armor that you lack proficiency with, you have disadvantage on any ability check, saving throw, or Attack roll that involves Strength or Dexterity, and you can’t cast Spells.

However, the PHB rules for Barding do not mention proficiency or these penalties.

Barding is armor designed to protect an animal’s head, neck, chest, and body. Any type of armor shown on the Armor table can be purchased as barding.

Note: This question is not asking whether the animal companion is proficient with barding. This question assumes the beast is neither proficient nor war-trained.

  • 1
    \$\begingroup\$ I would've thought so, since animal companions don't have any special rules about barding, but I'm open to being wrong - what makes it a different question? \$\endgroup\$
    – Miniman
    Mar 14, 2019 at 4:22
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    \$\begingroup\$ @Miniman The linked questions mention giving barding to animal companions, but their answers neglect to mention the disadvantage penalty. Also, the linked questions would suggest conflicting answers from the question regarding mounts. My question is here to clarify whether this penalty also applies to animal companions. \$\endgroup\$
    – MikeQ
    Mar 14, 2019 at 4:35
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    \$\begingroup\$ The answers may be missing what you're looking for, bur the question is identical and Includes your specific question. \$\endgroup\$
    – NotArch
    Mar 14, 2019 at 12:11