HeartGold & SoulSilver is the first expansion of the Pokémon Trading Card Game series of the same name, though often shortened to HGSS (the same abbreviation is also used for the expansion itself). Based on Pokémon HeartGold and SoulSilver themselves, the expansion includes mostly Pokémon from Generation II, which itself includes all Pokémon from Generation I. Unlike its predecessor, Neo Genesis, HeartGold & SoulSilver also consists of many Pokémon from the first generation, whereas Neo Genesis included only those related to new Pokémon (such as Horsea and Seadra, which had to be included for Kingdra's sake). In Japan, the expansion heralded the start of the Pokémon Card Game LEGEND series as two subsets, titled HeartGold Collection and SoulSilver Collection.
HeartGold & SoulSilver was the first expansion to use a revamped card design, which included multiple changes:
- The card border is now gold and silver as opposed to yellow.
- The illustrator's bar, the Pokémon stage bar and the Pokédex data strip all include tinges of gold.
- The evolution circle returns to the extreme top-left of the card. The stage name strip is extended further to the left due to this.
- An unfinished circle is present on Basic Pokémon cards where the evolution circle would be present on Stage 1 and 2 Pokémon cards.
- The flavor text area has been compressed further down with the illustrator's bar shortened in length to compensate.
- The top-right corner is now gold and silver to display the Hit Points more prominently.
HeartGold & SoulSilver also introduced two new mechanics, as well as discontinuing two other mechanics. Pokémon SP cards and Pokémon LV.X are no longer present, the latter due to the removal of levels on the cards. Pokémon LV.X were replaced by a new mechanic in the form of Pokémon Prime (Great Pokémon in Japan), Pokémon that are considerably rarer and more powerful than any of their regular counterparts. Pokémon Prime do not play home to any new mechanics: they do not have special names, there are no drawbacks to their use and they evolve the same as any other Pokémon. They have a holographic gold border, much like the silver border of Pokémon LV.X and Pokémon-ex before them, and additional graphics around the illustration box and the card name (which is also holographic gold). They also lack Pokédex data in order to free up space for more Pokémon Powers and attacks.
The second new mechanic to be introduced by the set was Pokémon LEGEND, named after the series in Japan. Pokémon LEGEND are comprised of two cards - a top half and a bottom half - and can include either one or two Pokémon. They can be put into play only during the game itself and only when both halves of the card are ready to be played at the same time. There are no real drawbacks; both halves of the card have the same name so only two of each have can be used in a 60-card deck. As well as that, Pokémon LEGEND cards depicting two Pokémon cause the opponent to take two Prize cards upon its defeat, much like with Pokémon-ex. Pokémon LEGEND cards are entirely holographic and three-quarters of the overall card is comprised of the illustration.
The Japanese version of the expansion also brings about a change to the long-standing Trainer card: The three different types of Trainer are now classified as Goods, Supporter and Stadium, though Goods cards retain their title of Trainer cards in English regions. Similarly to Supporter cards and Stadium cards, which were color-coded orange and green respectively after their reclassification in the Diamond & Pearl expansion, Goods cards (including Trainer cards in English) are now color-coded blue. As with Pokémon cards, Trainer cards have also been redesigned: the illustration box now has a gold outline and the text area is metallic silver.
Japan's set also introduced a type of card that had been present in English regions since the launch of Expedition Base Set in the form of reverse holographic cards, known in Japan as mirror cards (ミラーカード). These feature the same holofoil treatment as reverse holographic cards that has been present since Diamond & Pearl in English.
Trivia
- This expansion marks the first instance in the TCG in which one generation of cards has included three distince series; these are referred to as the DP Series, the PL Series and the HGSS Series (Pokémon Card Game DP, DPt and LEGEND respectively in Japan).
- The card revamp for this series of expansions marks only the second time in the TCG that the card layout has been revamped mid-generation, following the shift from Neo to e-Card in Generation II.
- Six evolutionary items are featured in multiple different artworks from the expansion:
- The Energy cards were the first ones that featured Pokémon:
