Dark Elixir (DE) is one of the most valuable resources in Clash of Clans, which can be collected by Dark Elixir Drills. This resource is used to buy, upgrade heroes and train Dark Elixir Troops.
There are two ways to get Dark Elixir in Clash of Clans. Plenty of players think that attack is the best way to get DE. But in my opinion, Investing in your DE Drills is actually the best way of getting DE. At level 8 of town hall, you can have a level 3 DE Drill. It can produce up to 1080 DE everyday. When your town hall hit level 9 with 2 level 6 Dark Elixir Drills, it will be 4800 DE everyday. And when you have level 10 town hall, it will be 7200 DE per day.