Marks are four powerful magical brands which appear in Ultima III, granting those who have been imprinted with them a variety of special powers.
The Marks could be obtained by touching special heated rods within the realm's dungeons. Contact with these brands was painful, and would injure those who wished to partake of them, dealing fifty damage to whomever touched them. Once the resultant sigil was seared into a character's flesh, however, that person would inherit the powers of the Mark for the remainder of their quest.
The Stranger and their company could learn of the Marks in the hidden city of Devil Guard, learning that taking on all four of the magical brands would be necessary to complete their campaign against Exodus.
- The Mark of Kings: Gave those who bore it favor with Lord British, that he might raise their experiential prowess above the fifth level; found in Dardin's Pit, the Dungeon of the Snake, the Perinian Depths, and the Dungeon of Time.
- The Mark of Fire: Granted its wearer the ability to pass unharmed through flame and lava; found in the Perinian Depths, the Dungeon of Fire and the Mines of Morinia.
- The Mark of Force: Allowed those who possessed it safe passage through force fields; found in the Dungeon of Fire and Mt. Doom.
- The Mark of the Snake: Spoken of by the inhabitants of Fawn, this Mark was necessary to pass the Great Earth Serpent which guarded the Isle of Fire provided one has the password. Found in the Snake Dungeon. Clues about this Mark can be found in .
- The Marks do not appear on the Stranger/Avatar's body in later installments of the series, and the powers which they granted the hero do not carry over past the death of Exodus.