Released in Japan as Galactic's Conquest, the first expansion of the newly-introduced Pokémon Card Game DPt series, the English release of Platinum begins a new series of cards in the English-language Trading Card Game, also called the Platinum series. This replaces "Diamond & Pearl" as the prefix for expansions, with PL replacing DP as the shortened name for the series.
Platinum is based on the Pokémon Platinum, due to be released six weeks after the set itself. The set itself is based on the changes between Pokémon Diamond and Pearl and Platinum, including Giratina in both its Altered Forme and its Origin Forme, as well as introducing Shaymin to the Trading Card Game. It also features Team Galactic's Pokémon and various Trainer cards based on them.
Platinum also introduces two new mechanics to the Trading Card Game. The first new mechanic is a new type of Pokémon known as Pokémon SP. Pokémon SP have an "SP" symbol in the bottom-left-hand corner of the illustration box and can seemingly vary depending on the theme of the expansion in which they appear. In Platinum, as part of Team Galactic's inclusion, SP Pokémon are represented as Pokémon G with the "" at the end of a Pokémon's name made to symbolize the fact that it is a Galactic's Pokémon. All Pokémon are Basic Pokémon and have an illustration of their owner in the bottom-right-hand corner of the illustration box, much like cards from Gym Heroes, Gym Challenge and Pokémon VS. In addition to that, all Pokémon G have a border with some gray in it.
The second new mechanic to be introduced is the Lost Zone. The Lost Zone is essentially a second discard pile: however, it is not located in the play area. Hence, cards that are moved to the Lost Zone cannot be retrieved by cards which specify the recovery of cards from the discard pile.
Platinum continues to reintroduce retro cards to the TCG, with Haymaker favorites Electabuzz, Hitmonchan, and Scyther returning to play.