Your Deck in each Match is made up of four Cards, plus the King. All players start off with Legionaries by default when they start a new game.
New Cards are unlocked by obtaining Card Pieces. These come most commonly from Chests, but can also be obtained from the in-game shop - under Offers & Freebies – or as rewards for Matches and Events.
Adapting your Deck to suit the different Arenas in the game is an essential strategy. Between Matches, you can change what Cards make up your Deck in the 'Your setup' menu.
To change your Deck, select the Card you want and press the 'Use' button before placing it in your Deck. Pressing the icon to the right of the Deck will allow you to change the formation of your Cards. You can also create up to three presets to easily switch between your favorite configurations.
When enough Card Pieces have been collected, that card can be upgraded. The progress bar on each Card shows how many Pieces are required, and will turn green when enough have been collected.
The Card can be upgraded by selecting it and pressing the ‘Upgrade’ button and paying the amount of Gold indicated. If the player does not have enough Gold to pay for the Upgrade, this number will be in red and the upgrade cannot be purchased.