This storage allows you to save your hard earned Dark Elixir. Dark Elixir is used to buy and upgrade the Heroes, and to train and upgrade Dark Elixir Troops.
The Dark Elixir Storage is a transparent, rectangular-shaped building. It is stated that this storage had to resemble a cube due to the Dark Elixir’s power.
6%, 5%, 4% (depending on the town hall level) of the total Dark Elixir in the storage (up to 2,000, 2,500, 3000) can be stolen by attackers, although loot penalties may change this amount (see Raids).
Upgrading your Dark Elixir Storage to a higher level than you require for storage purposes can potentially save Dark Elixir in a raid. As an attacker receives an amount of Dark Elixir proportional to the percentage of damage each hit causes, the higher health of the upgraded building results in less Dark Elixir per hit. It also takes longer to destroy, giving you more time for your defenses to destroy the attacker before they can steal all the available Dark Elixir.
The Dark Elixir Storage building takes up a 3×3 space.
Dark Elixir Storage remain fully functional while being upgraded, like all other Storage.
Some people deliberately avoid getting the drill and just get the storage because it is much faster to raid for Dark Elixir than it is to collect it on your own.
If a player without a Dark Elixir storage raids Dark Elixir, the looted Dark Elixir will not be stored and will simply disappear. It will, however, give credit toward the Heroic Heist Achievement.
Due to the low cap on Dark Elixir, it is sometimes difficult to tell if the Dark Elixir Storage is full; a level 6 Dark Elixir Storage with just under 40,000 Dark Elixir (almost enough to reach the 2,000 cap) is less than 20% full and therefore appears empty.
Dark Elixir is the most difficult resource to obtain, with the possible exception of Gems.
The Dark Elixir Storage is unlocked at Town Hall level 7, along with the Dark Elixir Drill.
As of the 2015, July Update, all kinds of Storage are now immune against Lightning Spells and Earthquake Spells.