The Dark Elixir Drill collects Dark Elixir from an unlimited underground reserve, and stores it until it is collected by the player and placed into a Dark Elixir Storage. When the drill is full, production will be stopped until it is collected.
Attackers can steal up to 75% of the uncollected Dark Elixir in the drill. Having too many uncollected resources will make players a more attractive target.
The Dark Elixir Drill takes up a 3×3 space.
After the 2014 Christmas update, the Dark Elixir Drill is unlocked at Town Hall level 7, along with the Storage. The second and third drills are now unlocked at Town Halls 8 and 10, respectively. Until the drill is constructed, Dark Elixir can only be obtained by raiding, participating in Clan Wars, collecting Dark Tombstones from dead Dark Elixir Troops and/or using Gems.
When you choose to upgrade a Dark Elixir Drill, it will automatically collect any uncollected Dark Elixir. Note that if your Dark Elixir Storage is full at that time, the uncollected Dark Elixir will be lost. During the upgrade the drill stops producing Dark Elixir; if it is destroyed in an attack while the upgrade is in progress, no resources will be lost to the attacker, as the drill is empty.
It can be difficult to see without zooming in, but you can visually tell approximately how much Dark Elixir a Dark Elixir Drill currently contains by looking at the glass box on the top rear portion of the drill. An empty (clear) box means the Drill is less than 20% full, while a full (black) box means the Drill is at least 60% full.
You can temporarily boost its production with Gems. Spending Gems will double the Drill’s production rate for 1 day.
When raiding, the easiest way to tell the difference between the various levels of enemy Drills is to look at the Drill’s footings. Unlike the top of the Drill, there is a very recognizable difference between the footings of all six levels.