Basic Pokémon are the foundation of all decks. Without them, a player cannot play the game since both players begin the game by placing a Basic Pokémon in the Active position on the field. Each Pokémon card depicts a Pokémon from the video games. Each player may have up to six Pokémon on the playing field at a time: one "Active" Pokémon and up to five on the bench. Each Pokémon card has a name, a type, and an amount of Health Points (HP).
All Pokémon feature attacks; these typically deal damage to the opponent's active Pokémon, or occasionally, their benched Pokémon; however, an attack may also perform different functions, such as drawing cards, inflicting Special Conditions, or altering the opponent's board state. The vast majority of these attacks require Energy, which comes in the form of Energy cards. Abilities, known as Poké-Powers and Poké-Bodies until 2011, are not attacks but simply effects that either are activated under certain conditions or remain in effect as long as the Pokémon with the Ability remains in play.
The other type of Pokémon card is an Evolved Pokémon. Basic Pokémon is Pokémon that have not evolved and can be played directly onto the Bench. In contrast, an Evolved Pokémon cannot normally be placed directly onto the field; they must be played on top of the corresponding lower-stage Pokémon. Stage 1 Pokémon evolve from Basic Pokémon, and Stage 2 Pokémon evolve from Stage 1 Pokémon. As a Pokémon evolves, it gains HP and its attacks change, typically becoming more powerful. Pokémon EX cards were first introduced in the TCG set EX Ruby and Sapphire, and typically have higher Hit Points than other Pokémon, yet award an extra prize card to the opponent when defeated. Baby Pokémon cards, introduced in Neo Genesis, are a special kind of Basic Pokémon that have low HP but attack with strange and occasionally very powerful effects. Mega Pokémon, introduced in XY, evolve from Pokémon-EX, but are a special stage; as such, effects on Stage 1 Pokémon do not apply to Mega Pokémon. Break Pokémon were also introduced in the BreakThrough Expansion Later In the X and Y Series. Variations of Basic, Evolved, and Baby Pokémon cards have appeared in many sets, usually indicated with a word before or after the Pokémon's name. Secret Rare Pokémon cards are some of the rarest cards. They are usually represented by a shiny holofoil and a gold outline. These cards include Shiny Pokémon, Trainers, alternate-art Pokémon, and some rarer Mega evolution cards. Pokémon-GX cards were introduced with the Pokémon Sun and Moon expansion. These cards have a specific move set at the bottom of their card that can only be used once per game. Only one GX move can be played per game, so if there are three different Pokémon-GX cards in your deck only one of the three GX moves can be used. Introduced with the Sun and Moon expansion are Alolan forms; existing Pokémon that have an alternate form with a different design and type.
Energy cards are attached to a Pokémon to power that Pokémon's attacks. Typically, only one Energy card may be played per turn. There are two main categories of Energy cards: Basic Energy and Special Energy. The nine different Basic Energy types, which correspond to Pokémon card types, are Grass, Fire, Water, Lightning, Psychic, Fighting, Darkness, Metal, and Fairy. Two additional types, Dragon and Colorless, do not have their Energy cards and instead use other types of Energy. Basic Energy cards are used only to fulfill costs for attacking and retreating, while Special Energy cards have additional benefits. Most attacks require a certain type and amount of Energy. If an attack requires a certain type and amount of Energy, then that type and amount of Energy must be attached to the Pokémon. If the attack has a Colorless Energy requirement, that requirement can be met by any Energy card.
Trainer cards perform various functions to affect the game, for example healing Pokémon, discarding energy from the opposing Pokémon or retrieving cards from the discard pile. Before the Diamond & Pearl expansion, all cards that were not Pokémon or Energy were considered Trainer cards. Trainers have since been subdivided into categories. Item cards directly affect the battling Pokémon, Tool cards are attached to a Pokémon and modify their features, Stadium cards affect the entire field, and Supporters are more powerful Items, only one of which can be played per turn.