Mario Circuit

Mario Circuit (, Mario Circuit) is a stage based on the course of the same name from  in and Super Smash Bros. Ultimate.

Stage overview
The stage takes place on a set of platforms that move around the track, and will stop at certain parts of the track, similar to, Port Town Aero Dive, and the 3DS-exclusive Mario Kart stage Rainbow Road. Shy Guys drive around the track is a reoccurring theme in the Mario Kart stages. Because of the track's antigravity effect, the road will sometimes be above or to the side of the fighters. Unlike in Mario Galaxy, fighters are not affected by the unusual gravity. The track is able to meteor smash anyone under it while moving. Star KO's are normally banned on the stage, though Screen KO's can happen. Before the platform rises up, in the Wii U version hears 3 pings, while Ultimate version hears the Lap 2 jingle.

There are eight locations the platforms can stop at. The platforms will skip a random number of locations between each stop as they follow the track. In order around the track:
 * A circular tower across from the castle. Not connected to the track.
 * A platform next to the bridge, with the track as the right sidewall.
 * A gap in the railing, with the track in the background below. Stacks of tires on the track act as a third platform under the gap, but if racers appear they will travel across this platform.
 * The underside of a long platform, with the track as the ceiling. Racers can hit a jump that sends them close to the platform.
 * Some platforms next to the other side of the bridge, with the track as the left sidewall.
 * A small island floating in the middle of nowhere. Not connected to the track.
 * A section of railing and brick wall, with the track in the background above.
 * The finish line, with the track and sidelines as the ground. The "Mario Kart" sign above is a long platform that avoids the racers.

Hazards off
When hazards are turned off, only the cars are removed. Gravity remains and players can still get hit by the road.

Ω forms and Battlefield form
In Super Smash Bros. for Wii U, the Ω form uses the same base platform as the regular form, but it cannot be passed through from below. The platform also doesn't stop at any locations, and the track doesn't interact with the stage.

In Super Smash Bros. Ultimate, the Ω form and Battlefield form are similar to the Ω form in SSB4; however, the main platform is resized and reshaped to match. The three soft platforms of the Battlefield form are metallic and unique.

Origin
is the name of a track that appears in every ' game since '. This stage is an accurate recreation of Mario Circuit in ' and ', which is a prime example of the twisting, -esque course layouts made possible by the game's new mechanic. The design references a Möbius Strip, which is used in experiments with magnets, including magnetic levitation, which ties back back to the anti-gravity mechanic.  is the first game that allowed Shy Guys as playable characters, but only through DS Download Play. If friends wanted to play the game together, but somebody didn't have the game, they could still connect together through DS Download Play. It wasn't until  that Shy Guys were playable through normal means. In this stage, the karts are driven by Shy Guys, and the karts they drive on are the s from that game.

Tournament legality
The movement of this stage causes stage hazards due to parts of the road dealing damage to fighters. Some of the landing positions also have strange layouts that make competitive fighting difficult; this stage is usually banned in competitive play.

Glitch
If a player ends up on the right side of the top platform when it transitions after taking a stop, the player will instantly die, albeit the other player won't. This will cause the stage to become invisible and the screen unable to move. After a few seconds, the screen will finally move but there'll be invisible platforms, along with invisible stages outside the moving stage.

Trivia

 * If a fighter is caught by a Boss Galaga or Beetle before the stage scrolls to the section where the road is above the fighters, but breaks free as the stage scrolls to that point, they may get stuck "inside" the road and constantly be knocked back and forth, taking damage until they are blasted outside of the road.
 * Karts driven by Toads were planned to appear, probably similar to the Shy Guys' role in the same stage.
 * In the 2 stops which feature the road to the side of the platform as a wall, it is possible under some conditions to get on top of the road's terrain. Since this is above the upper blast line, it will always result in a KO however.
 * Rarely, if the stage is played for 15 minutes or longer, it may restart twice, the first time being the correct looping process and the second time being as if the stage was restarted in Training Mode.
 * If the stage is restarted in Training Mode, all but one of the Shy Guys will disappear - the visible Shy Guy is the only one with a hitbox.
 * The Shy Guys Karts are shown to be always in anti-gravity form even in parts of the track where the track is normal, unlike in Mario Kart 8 where drivers need to drive pass the anti-gravity strip.
 * In Ultimate, the following Assist Trophies cannot appear on this stage: Skull Kid, Nightmare, Andross, Ashley, Devil and the Squid Sisters. Additionally, Lugia cannot be summoned from a Poké Ball on this stage.