If the Pokémon Darkness Energy is attached to damages the Defending Pokémon (after applying Weakness and Resistance), the attack does 10 more damage to the Defending Pokémon. At the end of every turn, put 1 damage counter on the Pokémon Darkness Energy is attached to, unless it's or has Dark in its name.
Darkness Energy provides Energy. (Doesn't count as a basic Energy card.)
Expedition Base Set print
If the Pokémon Darkness Energy is attached to does damage with an attack (after applying Weakness and Resistance), the attack does 10 more damage. At the end of every turn, put 1 damage counter on the Pokémon Darkness Energy is attached to, unless it's or has Dark in its name. Darkness Energy provides Energy. (Doesn't count as a basic Energy card.)
EX Ruby & Sapphire print
If the Pokémon Darkness Energy is attached to attacks, the attack does 10 more damage to the Active Pokémon (before applying Weakness and Resistance). Ignore this effect unless the Attacking Pokémon is or has Dark in its name. Darkness Energy provides Energy. (Doesn't count as a basic Energy card.)
The Aquapolis print includes a Dot Code strip for use with the e-Reader, and has the card ID C-58-#. The short strip contains a brief card summary. There is no long strip for this card.
Darkness Energy was first included in the Neo Genesis expansion with artwork by Milky Isobe, first released in the Japanese Gold, Silver, to a New World... expansion. In Japan, a print was included in the fourth volume of Pokémon Card Trainers released December 1999. It was reprinted in Japan in the Totodile Side Deck of the Intro Pack Neo and later in the Pokémon VS expansion with a new card layout. This card was first reprinted in English in the Expedition Base Set with the new e-Card Series card layout. It had altered text that allowed it to work when the Pokémon it was attached to damaged a Benched Pokémon.
When this card was included in the Aquapolis expansion, having previously been reprinted in the Japanese The Town on No Map expansion, the card text was reverted to that of the original Neo Genesis print. At the beginning of the EX Series, it was reprinted in the EX Ruby & Sapphire expansion utilizing the new card layout, originating from the Torchic Constructed Starter Deck. In Japan, a promotional print of this card was given away during the Gym Challenge Spring 2005. This card was also awarded as a prize to those who attended the Pokémon e-League throughout December 2003. The standard prize bears no difference to the EX Ruby & Sapphire print, whereas winner versions have "Winner" in the bottom right corner of the artwork. The EX Emerald expansion included another reprint of Darkness Energy, coming from the Side Deck of the Master Kit in Japan. EX Unseen Forces, EX Delta Species, and EX Holon Phantoms all contained reprints of this card, with the EX Holon Phantoms print originating from the Mightyena Quarter Deck of the Japanese Gift Box Mew • Lucario. The final reprint of Darkness Energy using Milky Isobe's art was included in the EX Power Keepers expansion, which was later released in Japan in the World Champions Pack.
Darkness Energy and Metal Energy are the most reprinted Special Energy cards.
Though both it and Metal Energy represented a type that was eventually as prevalent as the other seven TCG types, only four of this Energy could be included in a deck. This was a major hindrance to the inclusion of Pokémon of these two types in decks until Diamond & Pearl introduced a basic form of this card.
Darkness Energy was introduced to provide Energy for Pokémon of the newly introduced Darkness-type, which consisted of all Dark-type Pokémon from the games.