Third-age platelegs are a members-only piece of armour that are part of the third age warrior set. To wear the platelegs the player needs at least level 65 Defence. To obtain third age warrior platelegs, the player can either complete a Level 3 Treasure Trail, or trade with another player.
They are the strongest non-degradable leg armour piece having the same armour rating as bandos tassets. These are currently the most expensive platelegs and are mostly worn to show wealth.
It was long thought that the chances of obtaining a piece of third-age armour was of about 1 in 10,000 (according to Paul Gower), and in 2010 Mod Maylea stated that the odds are lower than 1 in 100,000 . However, a livestream with Mod Simon and James revealed the mechanics of Treasure Trail rewards in detail, meaning the actual chances could be calculated: approximately 1 in 16,896 per item roll for any of the 12 parts of third-age equipment, or approximately 1 in 202,752 for a specific part, per item roll - with an average of 5 item rewards per Trail, this gives approximately 1 in 3,380 for any part, or 1 in 40,551 for a specific part, per Trail completed. For a more detailed breakdown of drop mechanics and calculations, see Treasure Trails/Rewards#Hard.