The ring itself is the core of the Lord of the Rings, turning what otherwise would be good and balanced into something more chaotic and less good.
It shows that there's a pyramid that begins from the good but chaotic (like Turin Turambar) and constantly descends until it reaches the bottom of lawful evil (like Sauron). Therefore, you can create a universe of stories and contrasts just by being able to nudge the personalities of the characters in the right direction
