Pokémon-ex are a variant of Pokémon found in the Pokémon Trading Card Game. They first appeared in the EX Ruby & Sapphire expansion.
The ex in the name stands for extra, as indicated by a wide range of attacks that have some sort of additional effect on Pokémon-ex. For example, in the EX Deoxys expansion, there is a Grumpig which possesses an attack called "Extra Ball", which deals additional damage if used against a Pokémon-ex.
The major difference between Pokémon-ex and other types of Pokémon is that when a Pokémon-ex is Knocked Out, two Prize cards are taken, as opposed to the standard one. To compensate for this downside, Pokémon-ex are significantly stronger than other types of Pokémon. In the EX Ruby & Sapphire expansion, Pokémon-ex were basic Pokémon with relatively powerful attacks; however, in following expansions, they had taken on a number of other traits. Pokémon-ex may have up to two Weaknesses or Resistances and a Retreat cost of up to five. Some Pokémon-ex also have a large amount of HP; cards previously had a limit of 120 HP, but Pokémon-ex ignored this rule and had up to 200 HP. Before the Diamond & Pearl Great Encounters expansion, Wailord ex had the title of the most HP: 200. This was later tied with Wailord in the Great Encounters set and Wailord in the Dragons Exalted set, and later surpassed by M Pokémon-EX in the XY series.
Additionally, Pokémon-ex are immune to certain effects: for example, their Poké-Bodies are not deactivated by cards such as Space Center from EX Deoxys, but they are also excluded from the benefits of certain cards, such as Sitrus Berry from EX Unseen Forces, which cannot be attached to them. There are also certain cards that only affect Pokémon-ex, nearly always negatively. The most well known example would be Desert Ruins from EX Hidden Legends, which requires each player to put a damage counter on each of their Pokémon-ex with a maximum HP of 100 or more between turns.
Pokémon-GX have a stylized GX graphic on the card name.
Pokémon-GX work very similarly to both Pokémon-EX from the Black & White and XY series and Pokémon-ex from the EX Series. They possess considerably higher HP and stronger attacks compared to their regular counterparts. However, when a Pokémon-GX is Knocked Out, the opponent takes two Prize cards instead of one. Also like Pokémon-ex, Pokémon-GX are classified with their usual stage of Evolution, contrary to Pokémon-EX which had fully-evolved Pokémon as Basic Pokémon.
The main trait that makes Pokémon-GX differ from previous variant Pokémon is their exclusive mechanic called GX attacks. These attacks are based on the Z-Moves mechanic introduced in Pokémon Sun and Moon and like them, have more powerful effects and/or damage output than normal attacks. However, a player can only use one GX attack per game. A special GX marker is used to take note of whether the player has already used their GX attack or not.
Aesthetically, the artwork on Pokémon-GX covers most of the card, with the background illustration fading into the top and bottom-most areas, while still having the Pokémon break the card's borders (following on previous Pokémon variant cards). As such, the card text presented across the artwork is outlined, resembling Full Art cards. A blue and black bar containing the GX attack name separates it from the other attacks and the effect text is colored blue. Finally, the card border features a black line running over it.