I haven't paid a single cent so far and all cards are available to you.Kong Wen wrote: Are there cards that are pay-exclusive, or do you have the chance to randomly get any single card just through regular play? It would be pretty sketchy if they held back some of the good cards for booster packs that you have to buy.
You start with a fixed set of basic cards and unlock additional class-specific cards aswell as golden basics by leveling.
Most other cards are in the regular packs you unlock for 100 Gold (in-game currency) or certain achievements (Common/Rare/Epic/Legendary)
Another set of cards is unlocked by playing the campaign. Each campaign chapter can be unlocked for 700 G.
You can also craft cards by turning exess cards (you cannot trade with others) into dust and use it to unlock cards.
Each day you get a random quest which gives you 40-100 G, plus 10 G for every 3 wins in play mode (ranked or unranked). Up to three quests can be active at the same time.
Finally, for 150 G entry fee you can enter the Arena. Here you create a deck from randomized cards (not yours) and play until you lose 3 times. The more wins you get, the better the rewards (incl. cards, card packs, gold and dust). Usually you need ~three wins to get out more than you invested.
