Lord British's Amulet

Lord British's Amulet (sometimes known as the Serpent Amulet) is one of Lord British's Crown Jewels. It has the shape of a silver serpent. The Amulet is a very powerful magical item. Its two known powers are the ability to call a blue moongate to Britannia and to shed light into even the darkest places. It appears in  Ultima V.

Description
Lord British found the Amulet on Earth while he was still a youth, and it transported him to Sosaria, where he always kept it with him. However, when the Shadowlords abducted him during the expedition, the Amulet was left behind in the Underworld beneath dungeon Destard. The Avatar found it there, at the graves of the fallen knights of Lord British. The Amulet was the only way the Avatar could cross the darkness surrounding the dungeon Doom. After the Avatar rescued Lord British, the Amulet was returned to its owner, and was worn by him ever since.

Trivia

 * It is possible in Ultima V to follow Lord British's Journal to find the Amulet.
 * It is possible to steal the Amulet from Lord British in Ultima VI by using the spell Pickpocket. However, it doesn't have any special use in this game.

Ultima V: Lazarus
In Ultima V: Lazarus, the Amulet can be found after going into the Underworld by climbing down some falls in Spiritwood, following the footsteps of Lord British's ill-fated expedition. It can also be reached from dungeon Destard. Wearing the Amulet will surround the player with a very bright light.