Poker Face: Flotsam is a quest from Chapter 1 in The Witcher 2: Assassins of Kings.
When Geralt was staying in Vizima, he was less known among the gamblers as a witcher and more as a consummate dice poker player. His fame spread across all of Temeria and there were bound to be people in Flotsam who would recognize him as a gaming partner. Geralt was immediately invited for a game with two local players. He also learned about a third - the local champion, a man who wouldn't play with just anyone.
After defeating first two local players, Geralt was told to play dices with Einar Gausel.