Boxing Ring

The Boxing Ring is a stage appearing in Super Smash Bros. for Wii U and 3DS, originally from the Punch-Out!! Series, but it has an alternate version, where it is themed for the Smash Bros. series.

Design
A generic indoor stadium with a jumbotron, with a visible audience in the background, and fights taking place in a boxing ring. It has been shown that characters can stand on the ropes surrounding the ring and perform spring jumps off of them for extra height. It has also been shown that the lights high above can be knocked down to make the room darker, with the falling lights causing a powerful explosion.

It was shown to have "Smash Bros." signs and symbols initially, which made it unclear whether the stage was from Punch-Out!!, or if it was an original Smash stage. At Little Mac's reveal however, the Smash symbols were shown replaced with Punch-Out!! logos, showing that the stage is indeed a Punch-Out!! stage as was speculated since the stage's reveal. This led people to believe the Smash symbols were just placeholders to hide the fact it was a Punch-Out!! stage and by extension Little Mac's inclusion in the earlier trailers, but in a later Miiverse post by Sakurai, it was confirmed that the earlier seen Smash version will be another version of the stage. It's unknown at this time if there will be any non-aesthetic differences between the versions.

Initially this stage seemed to be exclusive to the Wii U version of the game, though with Little Mac's reveal, a 3DS version has been confirmed.

Origin
In every home-console Punch-Out!! game, the player plays as Little Mac as he works his way up in professional boxing circuits to become the World Video Boxing Assocation (WVBA) champion. The last circuit that Little Mac goes through is the World Circuit. The Punch-Out!! variation of this stage is loosely based on the World Circuit boxing ring that appears in Punch-Out!! for the Wii.

The concept of the ring itself seems to originate on King Dedede's boxing ring from the early Kirby games, as well as taking its modern-day elements from the recent Punch-Out!! games, including the scrolling text in the background; however, the text in Punch-Out!! read "World Circuit" rather than "Punch-Out!!".

In Kirby's Dream Land, the final boss battle against King Dedede takes place on a pecualiarly small boxing ring, which has a portrait of the king himself hanged in the background, there is no crowd to witness the fight, other than that, there is nothing special about it. This boss fight would be later recreated in Kirby Super Star sub game, Spring Breeze, where the boxing ring was made larger, a crowd composed of many Kirby regular enemies (including some guests like Mario, Luigi, Toad, etc.) and a marquee that reads "Champion: King Dedede vs. Challenger: Kirby".

Trivia

 * As Punch-Out!! is itself a fighting game series, Boxing Ring is one of only three stages in the Super Smash Bros. series to be featured as a stage in fighting games outside of the Super Smash Bros. series, the others being Green Hill Zone and Pyrosphere.
 * In a post, it is revealed that King Dedede might affect the stage as well, probably referring to the stage in the Kirby universe, where Dedede had a ring as well.