Overall, this stage works very similarly to Super Smash Bros. Melee's Pokémon Stadium: it switches from a basic version to type-inspired transformations. The layout of the basic version is extremely similar to the Melee version, with a main platform with a solid pillar underneath and two floating soft platforms on the sides. The background features a crowd, much farther away than the one in the original Pokémon Stadium, and a screen which, like the one in Pokémon Stadium, displays either the battle, a symbol denoting the upcoming transformation, or the current standing of players and the time remaining.
The other transformations, however, are all completely new. Like in Pokémon Stadium, they appear in no specific order and it is even possible for the stadium to change into the same type twice in a row. However, the stage always begins on the standard arena and has to revert to its normal state before transforming again. Several Pokémon appear in the background during the various phases, with no actual effect on the battle.
The Electric type version features two slightly raised conveyor belts which occupy the sides of the main platform, both pushing outwards. The center of the main platform is static. There are three soft platforms in varying locations: two, one above the other, are over the middle of the stage, while the third can be over either conveyor belt.
The Flying type version features fans in the ground which create an updraft, severely lowering the gravity: all characters' jumping abilities are enhanced and their falling time is increased. Characters flung upward have a much higher chance of being Star KO'ed. The updraft only extends above the platform. No other platforms are present, giving the stage a Final Destination style layout. The floor is also slightly raised.
In the Ground type variation the layout changes to a large solid mound of dirt on the left and a hut built into a tall rock on the right. The hut provides two platforms, the lower one being longer and curved, and the higher one being short and flat. No physics alterations are added.
In the Ice Type version all platforms and surfaces extremely slippery, so characters are more likely to trip. A hut can be seen in the background, and there are two icy platforms that slope inwards slightly.
A stage such as this has never been seen in any Pokémon game. There have been flat areas where trainers would do battle, but they were always inside buildings called 'gyms'. One reference could possibly be from the game Pokémon Stadium. The arenas in Pokémon Stadium have the Poké Ball logo in the center with crowds watching the battle. Another possible origin is from the anime. There have been gyms with a theme based on a Pokémon type, such as rock or electric, and the scenery would change to match the theme. However, the exact arrangements in this stage have never been seen in a Pokémon title. A possible source of inspiration for both this stage and its Melee Stage predecessor is the Pokémon anime television show, in which type-transforming arenas featured during the Pokémon League.
It is unconfirmed as to which region exactly the stage is set in, but reasons can be found for each region in the mainstream games, excluding the then-nonexistent Unova and Kalos.
- Johto: The N64 game introduced the Johto region's Pokémon to 3D, and may have been set in Johto itself.
- Hoenn: The Generation Three battle theme Wild Pokémon Battle! (Ruby/Sapphire) is the only "true" battle theme to appear on the stage. The theme originates from the Hoenn region.
- Sinnoh: The stage stars a number of Sinnoh-only Pokémon. In addition to this, the Brawl stage Spear Pillar originates in Sinnoh.
Comparing to the background (skyscrapers), it may be Saffron City or Celadon City of Kanto, Goldenrod City of Johto, Lilycove City of Hoenn, or the Fight Area/Battle Frontier of Sinnoh. It may be a mix, if the buildings seen are from various cities/regions. Alternatively, it may be White City from the game Pokémon Stadium 2.
In the Stadium's Ice mode, there is a cabin in the middle of the stage. Hidden in the cabin is a poster of a kitten, and what looks like the Wii Hint Cat on the same poster. It is unknown whose kitten is pictured on the poster, but it is rumored to be Masahiro Sakurai's.
- It is widely believed that the Flying transformation of Pokémon Stadium 2 is based on the Valley Windworks from the Sinnoh region. The inclusion of wind turbines is the main reason people think this. To further back up the theory, the rare Pokémon Drifloon makes a guest appearance here. In Diamond/Pearl/Platinum, Drifloon was only obtainable by finding it in front of the Valley Windworks on Fridays.
- Unlike the Melee Pokémon Stadium, characters fly in front of the screen in the background when Star K.O.'d.
- In the original Dojo screenshot of the Flying element of the stage, Drifloon and Hoppip are shown much farther away than in the final version of Brawl.
- When playing as Wario or Wario-Man, using a fully charged Wario Waft on the Flying stage will result in an instant Star KO.
- In Brawl, if playing as Zero Suit Samus the jumbotron on the background will still show the name "Samus" instead of "Zero Suit Samus", like in Pokémon Stadium.
- In Brawl, if this stage is featured in an event match (such as in Become the Champion!), the jumbotron in the background will not display "SUCCESS" when the player clears an event, but will display "FAILURE" when the player fails an event. This issue also happens in Pokémon Stadium and was fixed for both stages in the PAL version.