Third-age mage armour is a set of third-age armour for magic, and is the most powerful non-degrading magic armour available in Old School RuneScape, second in stats only to the degradable Ahrim's robes. A Magic level of 65 and a Defence level of 30 are required to wear this armour, except for the amulet which has no level requirements. To obtain this rare armour, players must either complete a Hard Treasure trail for a chance at receiving parts of it, or trade with players. The robes are so expensive that they are seldom used in combat and players who own them do so mostly as a show of wealth. Due to the rarity of the armour, players often pay hundreds of millions for a single piece.
The chance of receiving one piece of third-age armour from a treasure trail is 1 in 3,510. The chance of receiving a specific piece of third-age armour from a treasure trail is 1 in 42,120. Both of these odds were confirmed by Mod Mat K in a Level 3 Clue Chest Opening Live Stream on 2nd July 2014.