The witcher's silver blade actually has a steel core which is plated with a thick layer of silver which is lethal to magical beasts. This weapon was made specifically for slaying monsters born of magic, those which can not be hurt with common steel weapons.
In the second game its called Witchers' silver sword. If you start the game without importing a save file from the original game, Geralt must gather the components to craft such a sword to complete the quest A Sword for Monsters in Chapter I. The list of components is found in the document Diagram: Witcher's silver sword.
Associated quests Edit
- Geralt does start the game with this sword as part of his starting equipment, but loses it near the end of the prologue, to a dragon.