Dragon city


Elements
There are 8 basic elements for the dragons in the game. They are Terra, Flame, Sea, Nature, Electric, Ice, Metal, and Dark. Once you have gotten some rare dragons such as Cool Fire or Soccer Dragon, you will have a chance to breed a new type called the Legendary and later on Pure dragons.


Habitats and expanding
Now each element has its own habitat. Each habitat has its own pros and cons. The initial Terra habitat has a low gold cap(500) but the terra dragon has high gold/min earned. The sea habitat has a higher gold cap(7500) but the sea dragon has low gold/min potential. The solution would be to breed both together to get either the mud or waterfall dragon so that they can be put in the sea habitat.
As you can tell from the chart, Flame, Sea, Ice, Nature, Metal, Dark, and of course Legendary have decent gold caps. To earn plenty of gold, you will want to put most of your dragons in the above habitats. Unless you are an active player, I would not recommend having too many Terra habitats at all. One will do.
Expanding your territory becomes a necessity once you have way too many habitats.
The first 6 expansion is free and it will start to cost gold/gems/neighbors as you try to get the next island.


Gold and food
You earn gold by putting your dragons in the habitat. Each dragon earns a certain amount of gold/min. To increase the amount of gold/min they earn, you will have to level up your little babies by feeding them food.
In order to feed your dragons, you will have to build farms. Farms can be upgraded later to grow more food.
The most efficient way to use your gold to grow food at the beginning is the 30 second dragon bell. Once you get a lot of gold, it doesn’t matter which food you grow.


Experience and level
A great way to gain experience is to keep buying a farm and selling it again. As long as you have gold, you can gain experience easily by doing it over and over again.
Buy Food Farm -> 100 gold and 100 Exp -> Sell Food Farm -> 50 gold = Total cost for 100 Exp is 50 gold.
You can also do that for the Big Food Farm and Huge Food Farm.
Each level you gain gives you 1 gem and unlocks new habitats after you get to a certain level.


Gems
You can buy gems with real money and speed up EVERYTHING. However, that would totally destroy the fun. Besides using real money, you can also earn them in-game. Here are a few methods in which you can get gems:
1) Participate in the Dragon League Tournament in the Combat World located at the bottom right of the game screen. You use your dragons to fight other players’ dragons. Once you win the tourney, you will be awarded 2 gems and some gold.
2) Build a Dragon Stadium and use your dragons to fight in it. Each tournament you win gives you 2 gems and some gold.
3) The daily bonus reward located on the right side of the game screen gives you a small chance to win 45 gems.
4) Leveling up gives you 1 gem.
5) The Monday reward gives you 4 gems if you pick the right prize.


Buildings
The important buildings that you will need:
Breeding Mountain: This is the building you use to breed dragons.
Food Farm: You will need food to level your little babies.
Dragon Stadium: To increase your dragon’s strength and gain gems.
Temples: These will allow your dragons to advance past level 10.
Magic Temple: Dragons can get to level 15.
Noble Temple: Dragons can get to level 20.
Knight Temple: Dragons can get to level 25.
Master Temple: Dragons can get to level 30.
Ultra Breeding Tree: Another alternative to the breeding mountain. While it is not necessary, it can help speed up your breeding process.
Crystals: These can help improve your gold earning rate/min. However, the legendary dragons are much better than building crystals once you get your hands on one of them.