Released on October 24, 2003, in Japan, the Magma vs. Aqua set consists of 89 cards and maintained the variant Pokemon-themed expansion and featuring new owner's cards. Dual-type Pokemon made their first appearance in this set as well. Darkness is the secondary type of all dual-type Pokemon in this set. A fracture effect was used on the character windows of Team Magma Pokemon, while Team Aqua cards feature a bubble effect. The Japanese version of the set adds "EX" to the set title, indicating that the
The Japanese name for this set takes inspiration from the English set naming system by adding "EX" to the set title. The EX means this is an "extra" set, in that it deviates from releasing the rest of the Generation III Pokémon and features owner's Pokémon. Several websites and online retailers made the mistake in adding "EX" onto the names of the next expansions. Similarly, it was also originally thought that Team Rocket Strikes Back would have the title "ADV EX2", but the ADV prefix was abandoned after the release of Undone Seal.
Accompanying the Japanese set were Deck Kits, which contained two Half Decks. These contained many cards that could not be found in the main expansion, and were added when the English version was produced. Nintendo used the same packaging style for several English-exclusive deck kits, including EX Trainer Kit, EX Trainer Kit 2, and the World Championship Decks.