Players can gain or lose Trophies by either winning or losing battles.
The amount of Trophies a player gains or loses is based on how much more or how much less trophies the opponent has compared to his or hers. If the opponent has more Trophies, then the player will lose less trophies, and vice versa.
Getting a certain number of trophies unlocks a new Arena.
For example, 400+ Trophies is required to unlock the Bone Pit (Arena 2).
After entering an Arena, you can lose up to 50 below the required amount before dropping back to the previous Arena. For instance, if you lose a battle in Frozen Peak and end up with 2,270 , then you will still be in Frozen Peak until you fall below 2,250 (or accumulate 2,600 to reach the next Arena, Jungle Arena).