A card's Chi cost is displayed on the yellow icon at the top-left corner. The higher the Chi, the longer you must wait before it can be used. To avoid waiting, always have a few low Chi cards in your deck. +1 to your maximum Chi is awarded at the start of each turn, up to a total of ten if the match lasts that long. You can choose to spend 2 Chi once per turn to draw an equipment card from the Armory. These cards are used to enhance your warriors.