Traditionally, a witcher uses two swords, a steel sword for use on monsters sensitive to iron, and a silver sword, which is suitable for most monsters not sensitive to iron.
The steel swords which witchers make for themselves (or contract swordsmiths to make for them) are traditionally made from either meteoric or magnetite iron, and grant the weapon no superior, or magical qualities. It may be possible that iron-fearing monsters are affected more strongly by meteoric rather than earthly iron.
In the novels it is mentioned by Geralt that the steel sword is often mistaken for being primarily intended for fighting hostile people.
See also
Within the games, there are a number of steel swords that Geralt can use:
- Steel swords in the original game
- Steel swords in The Witcher 2