Ball cards can be obtained from:
- Cases that you get for victories
- Completed missions
- The Challenge
- Crown Cases
- Taking a Free Item in the Shop (with a chance)
- Purchasing in the Shop
- Ranking in the top 15 of your League
When you receive a ball card for the first time, that ball is unlocked. You can get its cards from any case, including cases from lower-level Alleys.
Your League adds a permanent bonus to the number of cards received from cases.