Silver swords are a witcher's primary weapon in monster slaying. It's common practice among witchers to carry two swords, one made of steel to combat humans and nonhumans (elves, dwarfs) and one made of silver with which to kill monsters. While being lethal to all manner of monsters, silver also possesses an ability to cancel out certain monsters' abilities. One example of this is the Moon Dust bomb in Witcher 3 Wild Hunt, which explodes in a hail of silver splinters and prevents certain creatures either from gaining immaterial form or transforming. Steel on the other hand does almost nothing to harm a monster, if the player attempts to attack a monster with a steel sword, Geralt will switch weapons when out of range.