Board Thread:Questions and Answers/@comment-209.55.96.69-20150619000916/@comment-24035373-20150707061510

the total sum of a raid deck's cost can't be more than your max unit cost.

when you are putting units into your raid deck, there is a "total cost : number/number" right above the "confirm skill" button. the number on the left can't be higher than the number on the right. the number on the left is the sum of the cost of the units used in the deck. A unit's cost is the bottom right number next to the big select button in a unit's "panel". the number on the right (near the bottom of the screen) is your max unit cost limit, it will increase as you level up.