From Bulbapedia, the community-driven Pokémon encyclopedia.
Japanese promotional poster
An example of a Pokémon BREAK
Pokémon BREAK (Japanese: ポケモンBREAK Pokémon BREAK) are a variant of Pokémon in the Pokémon Trading Card Game. They were first introduced in the BREAKthrough expansion (the Blue Shock and Red Flash expansions in Japan). Pokémon BREAK have a stylized graphic on the card name.
Pokémon BREAK are a special kind of Evolution card and can be evolved from either Basic Pokémon, Stage 1 Pokémon or Stage 2 Pokémon but they are considered their own separate stage of evolution. As such, cards that affect or search for "Evolution cards", also affect or can be used to search for Pokémon BREAK, while cards that specifically state "Stage 1 Pokémon" or "Stage 2 Pokémon" don't.
Pokémon BREAK are played sideways over their previous stage, covering the illustration box of the Pokémon, providing them with an HP boost and an additional attack or Ability, while maintaining the attacks, Abilities, Weaknesses, Resistances and Retreat Cost of the previous stage, similar to the Pokémon LV.X mechanic featured in the Diamond & Pearl Series. Also, like Pokémon LV.X and Pokémon Prime before, there are no specific drawbacks when playing a Pokémon BREAK.
In terms of design, all Pokémon BREAK cards feature CGI artwork of the Pokémon completely covered in gold, with sparks surrounding it, and a unique squared holofoil pattern in the background. The illustration covers almost the entire card.
Pokémon that have appeared as Pokémon BREAK