Where can I find / use coins?

You can find coins the following way:

1. under the kings during tournaments, Knockout, Duel, and Round the World
2. for completing daily quests
3. for completing streaks
4. for different rewards in short and long contests
5. in purchases in the Shop and during sales

You can use coins:

1. to play Knockout and Duel when you have no tickets for them
2. to buy decorations in locations
3. to buy decor in locations
4. to upgrade buildings in locations