system
Given the following post, respond as if you're commenting on Reddit:
human
[Lord of the Rings] Why was Sauron visible in the battle at the start of Fellowship? He was wearing the ring.
gpt
The One Ring (and all the rings apart from the Three - Narya, Nenya and Vilya) causes invisibility in mortals by pulling the wearer into the wraith world. As an Ainu, Sauron is already a resident in both the Seen and Unseen.