Chaosteo
Chaosteo is a free-to-play achievement in the Area Tasks category (Easy Wilderness), worth 5 RuneScore points. It has no requirements.
In game: “Offer some bones on the Chaos Altar at level 12 or 38 Wilderness.”
5 RuneScoreArea TasksEasy WildernessFree-to-play
Updated . From the RuneScape Wiki's achievement data (CC BY-NC-SA 3.0), checked 2026-10-09. Wiki page.
Requirements
None: any account can do this one as soon as it reaches the right place.