As you embark on your adventure, and in particular, Gwent Quest: Collect ‘em All, it is well worth pinpointing every single card you can obtain in a detailed manner, from every single vendor and player (all 159 of them!) This section details where to find the following:
Gwent Vendors
Gwent cards you purchase from Traders are listed. Look for traders (who are marked throughout the Atlas and in this section) with the 
icon by their name. These traders are responsible for selling (or giving) you 122 of the total number of Gwent cards (excluding the Innkeeps in Toussaint selling you random cards, which cannot be tracked). There are 29 different Vendors to find:
Two are available in White Orchard.
Six are available in Velen (No Man’s Land).
Eight are available in Novigrad (City and territories).
Five are available across the Isles of Skellige.
There is one “vendor” of sorts in the Duchy of Toussaint (Blood and Wine Expansion); Count Monnier who hands you the base Skellige Clans deck (24 cards!).
All of the seven Innkeeps throughout the Duchy of Toussaint have a supply of over 20 random cards from the four initial decks. The exact cards vary throughout your adventure, and the pool of cards you could find at these vendors is listed on the previous pages. For the purposes of this guide, these random cards do not count toward your card totals. You can carry, but not use, multiples of the same card over and above the number available in the preceding chart.
Gwent Players (Specific Cards)
Specific Gwent cards you win by challenging (usually named) Gwent players (who are marked throughout the Atlas and in this section) with the 
icon by their name are also listed. There are 55 different players with specific cards to hand over:
- One is in the Royal Palace in Vizima.
- Five are available in Velen (No Man’s Land), with a total of six cards to hand over.
- Ten are available within the walls of Novigrad City, with a total of 13 cards to hand over.
- Twelve are available outside Novigrad City, in the countryside and in Oxenfurt, with a total of 13 cards to hand over. Included is the “loose” card in Brunwich.
- Six are available across the Isles of Skellige, with a total of seven cards to hand over. There’s also a Skelliger you need to kill for one card, too.
20 are available throughout the Duchy of Toussaint (Blood and Wine Expansion). All grant you cards from the Skellige Clans deck (though King Bran is only awarded once, and two possible players have him).
These traders are responsible for you gathering 60 of the total number of Gwent cards.
Gwent Players (Random Or No Cards)
Random Gwent cards you win by challenging a Gwent player (usually a vendor, and marked throughout the Atlas and in this section) with the 
icon by their name are also listed. There are 66 different players with a random card to hand you:
- One is in White Orchard.
- Fifteen are in Velen (No Man’s Land).
- Seventeen are in Novigrad City.
- Seven are outside Novigrad City, in the countryside and in Oxenfurt.
- Twenty-six are available across the Isles of Skellige.
- Four are available throughout the duchy of Toussaint (Blood and Wine Expansion), but they don’t have a (random) card to give you; play them for practice or after betting money. One of the four Toussaint players, Barnabas-Basil Foulty, is the majordomo at the winery you can own, and acts as a practice player. You can choose the exact deck faction, and strength of his hand, without having to outlay (or win) any funds. He’s great for practicing against! Another three Toussaint players are found during the Gwent Tournament in Toussaint; these seven folk are only interested in either passing the time or betting for money.
With the exception of the Toussaint players, each player offers you one card only when you beat them for the first time. This means you must visit (and beat) a minimum of 52 of the 66 Gwent players (outside Toussaint) to obtain all the randomly-given cards. Also included are two “loose” cards found in a garden chest in Beauclair (Toussaint), at the end of a Secondary Quest.
Gwent Vendors and Players:
The remainder of this section is devoted to precisely pinpointing each Gwent trader or player across the Northern Realms.