To start this quest, one must play the Bloody Baron by either finding the notice in Crow's Perch or by talking to and challenging him (he uses the Northern Realms deck). Once defeated he will hand over the Sigismund Dijkstra card and give you the names of Velen's best players: Haddy, Old Sage, and a boatwright.
No matter how you obtain the list, now you can go play the other three in no particular order.
Once you beat all of them, you'll earn the Monsters leader's card, Eredin: Destroyer of Worlds.
- Though you might think it unlikely, even war-ravaged Velen boasted many prominent gwent players. They possessed certain valuable cards which Geralt wished to add to his collection. To do that, he needed to defeat them. The first on his "To Fleece" list: the Bloody Baron.
- In the end, Geralt crossed every name off his list and acquired all the valuable cards he sought.
- Win a unique card from the baron.
- Look for a unique card and information about other players in the baron's office. (only if you didn't play him before the end of Return to Crookback Bog).
- Win a unique card from the man in Oreton.
- Win a unique card from Haddy of Midcopse.
- Win a unique card from the soothsayer.
- After playing the Old Sage in Benek and completeing the quest, he'll direct you to play Haddy in Midcopse, even if you've already beaten Haddy.
- As of Patch 1.31, If you have not collected the unique gwent card from the Baron, simply go to Midcopse, search the Notice board and find Gwent: Looking for New Players. This will start you on the quest and enable you to recover the Bloody Baron's unique gwent card.