The One Ring is the central fictional object in J.R.R. Tolkien’s The Lord of the Rings.
Sauron forged the One Ring in the fires of Mount Doom to control the other Rings of Power. He placed much of his power into it, which made the Ring both a weapon and a vulnerability. Its destruction is the central objective of the quest undertaken by Frodo Baggins and his companions.
The Ring can make its wearer invisible to ordinary sight, but invisibility is only one of its effects. It also exerts a corrupting influence and can reveal or amplify the desires of those who seek to possess it. Its power is especially dangerous because it promises control while gradually enslaving its owner.
The One Ring is distinct from the Silmarils, which belong mainly to the earlier history of Tolkien’s legendarium. It is also not the same as a palantír, a seeing-stone, or Sting, Bilbo and Frodo’s sword.