This was the first expansion in Japan to feature cards on the e-series layout, first featured in English in Expedition Base Set. A "VS" symbol appears in the corner, replaced with the "e" symbol in later expansions. This was likely a taster for Japanese players for the upcoming e-sets, as these cards feature no Dot-Code data. The Japanese card back design also changed from the old "Pocket Monsters Card Game" to the current "Pokémon" design to keep a universal identity for all countries that had adopted the game.
Pokémon VS introduced two long-term game mechanics. The first was the classification of Special Conditions, which saved the need to reference a number of them in attack or Pokémon Power effects. Burned was also added as a Special Condition. These changes would eventually be implemented in English in Expedition Base Set. The second were Technical Machine cards, which, like their namesake in the Pokémon games, allow the Pokémon they are attached to use an attack as specified on the card. These cards would also debut in English in Expedition Base Set.
This expansion was distributed in a non-conventional manner. While the cards were still packaged in foil packs, each of these packs contained 30 cards instead of the traditional 10 cards, costing ¥690 instead of ¥300. This was also the first time the term 'half deck' was officially used and became a recognized method of gameplay. There were three random half decks released: Grass & Lightning, Water & Fire, and Fighting & Psychic. Each half deck contained a random assortment of set type Pokémon (i.e. one could only get a Fire-type Pokémon in the Water & Fire half deck). Colorless-type Pokémon and Trainer cards could be found in all half decks.
The 30 cards in each booster pack consisted of: 11 energy cards, 11 character cards, 6 trainer cards (2 of which were TMs), 1 holo character card, and 1 holo special energy card.
A Grass/Lightning booster pack features 4 trainers, 2 TMs (Bugsy, Whitney, Jasmine, Janine) 5 Grass-type Pokémon, 3 Lightning-type Pokémon, 3 Colorless-type Pokémon (available in this pack are Whitney's Miltank, Furret, Lickitung, Clefable, Wigglytuff, Lance's Dragonite.) 6 Grass energy, 5 Lightning energy, 1 Holo Metal energy, and 1 Holo Metal-type Pokémon (Falkner's Skarmory, Bugsy's Scizor, Jasmine's Steelix, Bruno's Steelix).
A Psychic/Fighting booster pack features 4 trainers, 2 TMs (Morty, Chuck, Will, Bruno, Rocket), 5 Psychic-type Pokémon, 3 Fighting-type Pokémon, 3 Colorless-type Pokémon (available in this pack are Falkner's Togetic, Whitney's Persian, Morty's Noctowl, Chuck's Tauros, Granbull, Bruno's Ursaring.), 6 Fighting energy, 5 Psychic energy, 1 Holo Rainbow energy, and 1 Holo Rocket's Pokémon (Wobbuffet, Raikou, Entei, Suicune).
A Fire/Water booster pack features 4 trainers, 2 TMs (Falkner, Pryce, Clair, Karen, Lance), 5 Water-type Pokémon, 3 Fire-type Pokémon, 3 Colorless-type Pokémon (available in this pack are Falkner's Pidgeot, Fearow, Dodrio, Farfetch'd, Delibird, Claire's Dragonite.), 6 Water energy, 5 Fire energy, 1 Holo Dark energy, 1 Holo Dark-type Pokémon (Morty's Murkrow, Pryce's Sneasel, Karen's Tyranitar, Umbreon).
Pokémon VS was also the first Japanese expansion to use a numbering system. Instead of ordering them alphabetically and in descending rarity as with English expansions, the Japanese system has always ordered cards by type and National Pokédex number. This expansion slightly modifies this by categorising them by Gym Leader encounter order, followed by the Elite Four, Team Rocket, and the Champion.
Wizards of the Coast officially stated that they had no plans to release the VS set, primarily because they had competitive play in mind. Some cards from this expansion were still released in English in the Tyranitar Half Deck; however, these cards were produced by MEDIAFACTORY and received a limited release to competitors of the 2001 Tropical Mega Battle. Despite this statement, Pokémon USA localized the Generation IV equivalent, Pokémon SP when they debuted in the Platinum expansion.
Trivia
This was also the first Japanese expansion to feature a secret card: Rocket's Tyranitar, which could only be found in the Tyranitar Half Deck, distributed in conjunction with the Japanese theatrical release of Celebi: a Timeless Encounter.
All Gym Leaders from Kanto and Johto are present in this expansion, excluding Giovanni and Blue.
The only uncommon cards in this expansion are Trainer cards.
This was the first Japanese expansion to include 1st Edition cards.
This was the first time a Holofoil rare Legendary Pokemon - Entei, Raikou, Suicune, appeared with a 1st Edition Stamp in Japan.
However, the first time a 1st Edition stamp appeared on a Holofoil rare Charizard, Blastoise and Venusaur in Japan was the Dark Charizard, Dark Blastoise and Dark Venusaur from the 2001 Pokémon Web series.