Achievements
Achievements are task you can complete in order to receive rewards, such as; Skilling Outfits, Crystal keys, Donator Scrolls, Experience lamps, and Fortune Tokens. Achievements are divided into 4 difficulties: Easy, Medium, Hard, and Elite.
The Achievements can be found by going to the Character Summary tab to the left of your Inventory, then clicking on Achievements.
Completing all Achievements is a requirement to unlock the Completionist cape.
Easy
Medium
Hard