Mercenary is a person who comes into an armed conflict for their own economic benefit: for money or other tangible benefits.
The Witcher books
Condottieri (singular condottiero and condottiere) are not just mercenaries, but the leaders of groups of professional military "Free Companies". In the Witcher saga, king Esterad Thyssen of Kovir and Poviss released some political prisoners formerly known as the "Sly cats" on the condition that they support the efforts to push back the Nilfgaardian invasion at the battles of Mayena and Brenna.
Famous condottieri and mercenaires
In The Witcher computer game
In the games the mercenaries are usually security units (instead of Rayla, the order mercenary) You can find them:
The known ones were:
The Torch Guardian has the same model, as the mercenaries.
In The Price of Neutrality premium module
In the module, there is a large gang of mercenaries led by Merton Bringgs to find Deidre. You can find them in their camp. Depending on Geralt's choices, all the members will die. Notable members were:
In the "Side Effects" premium module