Sparring Ring

Sparring Ring is a stage in, released in the Version 3.1.0 update on 2017-09-28. Previously, the stage was only used to warm up in lobbies, but was made available for all modes in Version 3.1.0. At the time, it was the first and only stage to not correspond to a fighter, and seemed to be themed after the ARMS Laboratories in general instead. However, when Springtron was added as a playable character in Version 4.1.0, Sparring Ring became his home stage.

Appearance
Sparring Ring is a flat, square boxing ring with no obstacles to interfere with gameplay. The floor has a large yellow circle on a black background, and in the middle of the yellow circle is a smaller black circle with the ARMS Laboratories logo in yellow. Yellow foam bars run along with outside of the ring, and outside are tall walls and canopies providing shade up above.

Trivia

 * Sparring Ring was the first and so far the only stage to be added to the game without a fighter. It is also the only instance of a stage that was assigned a character after it was released.