Mercenaries are cards that can be borrowed for a certain number of games. Players can only access Mercenary cards from the list of cards they have already unlocked. Players cannot get cards that require reaching a certain level to unlock them. Players can only play with one version of the card in their deck - Normal, Veteran or Mercenary.
Players can purchase Mercenary Cards in the "Mercenary deals" section of the shop. All slots in the store are unlocked to players, and each slot provides a random level of mercenaries (levels 1-10) for a random number of games (levels -2 to +5). Mercenaries are calculated from the average level of players' 12 highest leveled cards.