The medallion of the thieves guild is an imitation of that used by honest men. To a lawful guildsman, the altered medallion is a mockery — a ruined medallion of false belonging. To a thief, however, it is legitimacy by inversion: “I take what you made, and make it mine.”
The medallions are all stolen and no guilded thief would have one made, for to do so would show they were unworthy of it. Many are taken from dead or drunken journeymen, especially in back alleys. Some are pawned off by the desperate and degenerate, who find themselves stripped of guild protection afterward.
The medallions are modified by being worn down on stone, iron, or cobblestones, leaving a smoothed, scarred surface. This will leave a crude result with a ghost of the eight pointed star still faintly visible.
The medallion is then heated and an iron stamp in the shape of a keyhole is hammered through its center. This leaves the medallion warped, cracked, and unmistakably altered — a bold statement that the bearer belongs to the only guild that matters to them.
Of course, any gemstone inset (like that of the masters) is pried out. In its place the hole is plugged with resin or glass, or a smear of black pitch, and sometimes left hollow — proof the medallion has been “liberated.” Others use the hollow to conceal poisons, powders and the like.
The keyhole shape is not random. Each of the cities has its own to distinguish it from the others. A thief is sure to know the shape of the city he lives in and those of the nearest cities to him. Beyond that, only the very learned of the thieves will know. The keyhole in the center becomes a perfect unifying emblem: all locks are theirs to open.
Some thieves carve small notches along the edge, serving as codes of crew, city, or rank.
