Board Thread:Question and Answer/@comment-68.189.13.117-20150324022240/@comment-25151790-20150324030754

Those blue numbers are bonus stats. The amount of bonus stats of a card is determined by the card's white stats. If a card has 1000 ATK (white) and a total bonus of +5% ATK, you would have a bonus of 50 ATK (blue). There are various ways to increase bonus stats.

If you max the friendship of a card, that card gains a permanent +5% ATK/DEF bonus.

There are Unit Bonuses that you can get by putting certain cards together in the same unit. One example of this is having 3 Passion cards in the same unit, which grants a +5% ATK bonus. Having 5 Passion cards in the same unit grants +10% ATK instead.

You can build up to two of each elemental building, which gives up to a total bonus of +40% ATK/DEF to cards with the same element as the building. For example, one Level 10 Fire Ruins gives +20% ATK/DEF to all Passion cards.

Finally, you can buy an upgrade potion from the Shop with jewels. It gives a +20% ATK/DEF bonus to all cards for 7 days.