Chest contains rewards including cards, gold, and gems but different chests give different rewards in different numbers.
There are 7 types of chests, which drop in Arena
Wooden Chest
Free chests are automatically obtained every 4 hours but will only stack up to 2 until you unlock one of them. After you have 2 free chests waiting, the timer for the next free chest will be stopped until you collect one of your waiting free chests.
Crown Chest
Crown chest is unlocked after you win 10 crowns in battles. After open a Crown Chest you have to wait 24 hours to start collecting 10 crowns again. Crown chest always contains gems(2-4).
Silver Chest
Silver Chest is obtained through winning in Arena battles. It takes 3 hours to unlock without using gems. Silver Chest includes certain amount of gold and cards depending on its level. You have a chance to get gems from it.
Golden Chest
Silver Chest is obtained through winning in Arena battles. It takes 8 hours to unlock without using gems. Golden Chest includes certain amount of gold and cards depending on its level. You have a chance to get gems from it.
* if it's purchased from the store, it can be opened instantly
Giant Chest
Giant Chest is obtained through winning in Arena battles or purchasing in store. It takes 12 hours to unlock without using gems. Giant Chest includes certain amount of gold and cards depending on its level. You have a chance to get gems from it.
* if it's purchased from the store, it can be opened instantly
Magical Chest
Silver Chest is obtained through winning in Arena battles or purchasing in store. It takes 12 hours to unlock without using gems. Magical Chest includes certain amount of gold and cards depending on its level. You have a chance to get gems from it.
* if it's purchased from the store, it can be opened instantly
Super Magical Chest
Silver Chest is obtained through winning in Arena battles or purchasing in store. It takes 24 hours to unlock without using gems. Super Magical Chest includes certain amount of gold and cards depending on its level. You have a chance to get gems from it.
* if it's purchased from the store, it can be opened instantly
Chest Level, Home Arena and Visited Arena
Chest level is determined by the Arena level you fight in. Say you just fought and won a battle in Arena 5 then you got a level 5 chest.
Home arena is the arena whose level is aligned to your trophy. Visited arena is the arena whose level aligned to your opponent's trophy. That means even your home arena is Arena 4 you may still battle in Arena 5 if you are visitor.
There are 7 types of chests, which drop in Arena
Wooden Chest
Free chests are automatically obtained every 4 hours but will only stack up to 2 until you unlock one of them. After you have 2 free chests waiting, the timer for the next free chest will be stopped until you collect one of your waiting free chests.
Crown Chest
Crown chest is unlocked after you win 10 crowns in battles. After open a Crown Chest you have to wait 24 hours to start collecting 10 crowns again. Crown chest always contains gems(2-4).
Silver Chest
Silver Chest is obtained through winning in Arena battles. It takes 3 hours to unlock without using gems. Silver Chest includes certain amount of gold and cards depending on its level. You have a chance to get gems from it.
Golden Chest

Silver Chest is obtained through winning in Arena battles. It takes 8 hours to unlock without using gems. Golden Chest includes certain amount of gold and cards depending on its level. You have a chance to get gems from it.
* if it's purchased from the store, it can be opened instantly
Giant Chest
Giant Chest is obtained through winning in Arena battles or purchasing in store. It takes 12 hours to unlock without using gems. Giant Chest includes certain amount of gold and cards depending on its level. You have a chance to get gems from it.
* if it's purchased from the store, it can be opened instantly
Magical Chest

Silver Chest is obtained through winning in Arena battles or purchasing in store. It takes 12 hours to unlock without using gems. Magical Chest includes certain amount of gold and cards depending on its level. You have a chance to get gems from it.
* if it's purchased from the store, it can be opened instantly
Super Magical Chest
Silver Chest is obtained through winning in Arena battles or purchasing in store. It takes 24 hours to unlock without using gems. Super Magical Chest includes certain amount of gold and cards depending on its level. You have a chance to get gems from it.
* if it's purchased from the store, it can be opened instantly
Chest Level, Home Arena and Visited Arena
Chest level is determined by the Arena level you fight in. Say you just fought and won a battle in Arena 5 then you got a level 5 chest.
Home arena is the arena whose level is aligned to your trophy. Visited arena is the arena whose level aligned to your opponent's trophy. That means even your home arena is Arena 4 you may still battle in Arena 5 if you are visitor.