Rings

Description
Magical Rings are for the magic-users and the mundane alike. The use of these rings is quite simple: put a ring on your finger, and whatever magical ability it grants takes effect immediately. However, magic rings that provide regeneration or invisibility also have a drawback: they vanish after a period of use. Still, they are a must-have for adventurers, to be used only when necessary, in order to preserve them. Protection rings on the other hand do not vanish.

History
Magical rings of all three variants (protection, invisibilty and regeneration) first appeared in  Ultima V. From there on, they functioned the same (none appeared in  Ultima VIII and  Ultima IX). Other variants of magical rings with new effects, which were not special items, appeared in the Ultima Underworld games, working under different rules.

Variants
Magic rings exist in three variants in Britannia:

Ultima V
Invisibility Rings may be found at the following locations in Ultima V:
 * Can be bought at Buccaneers Booty in Buccaneer's Den for 450 gp.

Ultima VI
Invisibility Rings may be found at the following locations in Ultima VI:
 * Buccaneer's Den, in possession of Leodon.
 * In the dungeon Destard.
 * Castle Britannia, inside the chest of Phoenix at the lower levels of the sewers beneath the castle.
 * Can be found at the Sword and Keg of Jhelom hidden in a mouse hole. You'll need Sherry to get it.
 * Moonglow, four of them can be found inside a magically locked chest in the house of Penumbra. Beware of the two Skeletons!
 * In the crate in Katrina's house on New Magincia.
 * Two in the pirate's treasure room of the Pirate Cave.
 * Trinsic, in Whitsaber's house (taking it means stealing!).
 * In a chest in a small house in southern Trinsic.
 * Yew, inside one of the secret rooms at Nicodemus house, behind his crystal ball.

Ultima Underworld
Invisibility Rings may be found at the following locations in Ultima Underworld:
 * The gold Ring of Invisibility is found on Garamon's remains on level eight and never runs out of charges.

Ultima VII
Invisibility Rings may be found at the following locations in Ultima VII:

Ultima Underworld II
Invisibility Rings may be found at the following locations in Ultima Underworld II:

Ultima VII Part Two
Invisibility Rings may be found at the following locations in Ultima VII Part Two:
 * Dream Realm, in the throne room of Lord British.
 * Inn of the Sleeping Bull, at the monolith at 100S/39E.
 * Mountains of Freedom, inside the barrel, in the body of a child, next to the grieving ranger at the lever room.
 * Mountains of Freedom, at the store in the entry hall.
 * Shamino's Castle, in the wizard's quarters.

Ultima V
Protection Rings may be found at the following locations in Ultima V:
 * Can be bought at North Star Armoury in Castle Britannia for 500 gp.

Ultima VI
Protection Rings may be found at the following locations in Ultima VI:
 * Castle Britannia, it is worn by Lord British. (stealing, since the spell Pickpocket is needed to get it)
 * Castle Britannia, on a fallen body in a small room above the lower dungeons beneath the castle.
 * In the dungeon Deceit, on the mage's body in the cave with 3 bodies.
 * In dungeon Destard.
 * Moonglow, inside one of the chests in the west room of the lowest level deep within the Moonglow Catacombs below the city.

Ultima Underworld
Protection Rings may be found at the following locations in Ultima Underworld:
 * The red ring of Resist Blows is found in the bandit's storage room on the third level.

Ultima VII
Protection Rings may be found at the following locations in Ultima VII:
 * Under some debris of a camp fire, inside a cave, south of the Shipwright Owen in Minoc.
 * In the vault of the mad "Sultan" Martingo on Spektran.

Ultima Underworld II
Protection Rings may be found at the following locations in Ultima Underworld II:
 * The Ring of Protection is found on the first level of Anodunos, after falling off the dam control and finding a cave next to the water channel. It has unlimited use.

Ultima VII Part Two
Protection Rings may be found at the following locations in Ultima VII Part Two:
 * On the guard's corpse who lies the most southern at the throne room in the Dream Realm.

Ultima V
Regeneration Rings may be found at the following locations in Ultima V:
 * Can be bought at The Shattered Shield in Bordermarch for 200 gp.
 * Castle Britannia, inside a crate in the basement.

Ultima VI
Regeneration Rings may be found at the following locations in Ultima VI:
 * Castle Britannia, it is worn by Lord British. (stealing, since the spell Pickpocket is needed to get it)
 * In the dungeon Deceit, on the mage's body in the cave with 3 bodies.
 * In the dungeon Destard.
 * Moonglow, inside one of the chests in the west room of the lowest level deep within the Moonglow Catacombs below the city.

Ultima Underworld
Regeneration Rings may be found at the following locations in Ultima Underworld:
 * The silver Ring of Regeneration is found on a small island surrounded by lava in the western parts of level eight.

Ultima VII
Regeneration Rings may be found at the following locations in Ultima VII:
 * Lock Lake, behind one of the houses, inside a dead fox, inside a dead mouse.
 * In the vault of the mad "Sultan" Martingo on Spektran.

Ultima Underworld II
Regeneration Rings may be found at the following locations in Ultima Underworld II:
 * The Ring of Regeneration is found on the third level of Loth's tomb in the center behind a secret door. It is the only one but never runs out of charges.

Ultima VII Part Two
Regeneration Rings may be found at the following locations in Ultima VII Part Two:
 * Dream Realm, nearby Cantra in one of the two nightstands.
 * Gorlab Swamp, at a ruin.
 * Mountains of Freedom, before the drawbridge.
 * Mountains of Freedom, inside the chest by the Naga.

Lore
...

Trivia

 * Some other rings than these important ones, like the Blink Ring, Ring of Leap, Ring of Levitate, Ring of Magic Protection, Rinng of Mana Regeneration and others exists as well.


 * There also are special magical rings like the Ethereal Ring, Force Field Ring or the Ring of Reagents, but these rare items are listed separately.


 * Magical rings found in the Underworld series do not vanish from use, remaining available infinitely.