In Dragon City, players are able to battle other dragons with their own. This is called Combat.
Players can fight dragons in the Stadium which you can build, or in the Combat World where you compete against other players' dragons. Both of these battles have gem rewards which can be used for speeding up breeding, and hatching; or can be used to purchase items, such as buildings and eggs. Also some Event Islands do have combat challenges.
Also known as PvP League, Combat World or Dragon League, this is a place where you can fight other people's dragons.
You can use up to 3 dragons in this battle with the only requirement being that they are level 4 or higher. You progress through a league by beating the other players.
The number of combats left will decrease by 1 for every battle. You can have 3 combats within any 6 hour period. After using up all your available combats, you will have to wait another 6 hours. By beating 7 players in one league, you are awarded gems (originally 3, reduced to 2 in Jan. 2013, still 3 on Mobiles) and you advance to the next league.
After rotation, this user has 1 more option to choose opponent. Note at progress is 6/7 and there are 2 players to choose
Sometimes you may get an opponent that is very hard to beat, and it may take a while to level up your dragon to become stronger. The good news is, Dragon City has implemented a feature to rotate the island from time to time. Players report that Social Point has indicated the rotation occurs whenever a Player in the list graduates to the next League. When the island rotates, the players are moved to different islands, but the red X (indicator of which opponent you have beaten) remains in the same position. This rotation may move the harder opponent to an X and open up an easier opponent to battle again and sometimes you. Players need to win 7 battle to advance. Those 7 wins do not have to be against 7 different opponents.
The opponent is so strong that you do not have a strong dragon to win. Dont worry, this feature can help you win although the opponent has a hundred strong dragons. After using up all your available combats, you will have to wait another 6 hours. By beating 7 players in one league, you are awarded gems (originally 3, reduced to 2 in Jan. 2013, still 3 on Mobiles) and you advance to the next league. You can do this feature again without having to wait 6 hours. :>