The Witchers' medallion is a silver symbol of the witchers' profession, each one is shaped to represent the school a witcher comes from. It is sensitive to magic, vibrating and tugging on its chain when spells are being cast or magical beings, like genies, are present. This magic medallion shaped like a wolf's head is given to every young witcher candidate who has passed the Trial of the Grasses. The origin of the first medallions is unknown, though it is assumed they were made in the magic forge at Kaer Morhen. The medallions vibrate in response to magic in all its forms, including curses, charms and spells. They also warn of lurking monsters born of magic or magic experimentation.
- According to Geralt in the short story A Grain of Truth, no monster can touch a witcher's medallion.
- Leo Bonhart boasts a collection of three witcher medallions: a cat, a griffon and a wolf. After Bonhart's death in Pani Jeziora, Ciri claims the cat medallion for herself, gives the wolf one to Geralt (whose own original medallion was destroyed near the end of Wieża Jaskółki) and the griffon one to Yennefer.
- In The Voice of Reason, part 4, Geralt refers to his as "the Sign of the Wolf's School".
- A wolf's-head keychain was part of the packaging for some editions of the original game.
If the medallion is tuned to detect monsters, it will vibrate whenever a monster is near. When the monster is very close, there will also be a red haze around the left side of the screen, and the medallion will vibrate quite violently.
If the medallion is tuned to detect magic, then it will vibrate in the same manner when in proximity to a Place of Power.
The medallion emits an audible vibration when in the presence of magic. It can be used when energized, as indicated by a pulsating yellow aura. Using the causes the medallion to highlight items such as herbs, monsters, monster remains and containers in orange, and Circles of Power in red; this function is extremely helpful in cluttered and overgrown areas. Surrounding the medallion are the player's various level indicators:
- Vitality – indicates Geralt's health level. Reduction to zero results in death.
- Vigor – necessary to cast signs and/or block enemy blows.
- Toxicity – increases for the duration of each potion consumed, effectively limiting how many may be active at once.
In the Witcher 3 Wild Hunt the medallion has a diminished role, being largely replaced by witcher seneses, an ability that wasn't present in previous installments of the trilogy. Though it gets mentioned when Geralt talks to someone generating magic such as a cursed being, and vibrates infrequently (whether pointing out a clue or warning of danger) as the player explores the world.