Cards Gold and Tower Stones can be obtained from Card Packs.
A set period of time is required to open Card Packs.
The time it takes to open Card Packs vary. The more luxurious the Card Pack, the more time it will take to open.
Crystals may be used to open Card Packs immediately. The required amount will be determined by the remaining time on the timer.
Note that if all 5 of your Card Pack slots on the League screen are full, you cannot receive any more Card Packs even if you win a match.