The Spiked Armor can be found in Sword Coast Adventurer’s Guide, page 121.
This magic armor has a dull, rusty color or has veins of ruidium running through it. While you wear this armor, you gain the following benefits:
When you roll a 1 on a saving throw while wearing this armor, you must make a DC 15 Charisma saving throw. On a failed save, you gain 1 level of exhaustion. If you are not already suffering from ruidium corruption, you become corrupted when you fail this save.
If the Apotheon is killed or redeemed, all the ruidium in Exandria is destroyed instantly, and ruidium armor becomes +1 armor.
Spiked armor is a rare type of medium armor made by dwarves. It consists of a leather coat and leggings covered with spikes that are usually made of metal.
The wearer has Disadvantage on Dexterity (Stealth) checks.