The Online Practice Stage (also known by other names, such as Waiting Room) is a stage of sorts in SSBB. It is played in when a person is waiting for a Wi-Fi match to load. The player is given the opportunity to practice for the match on Sandbag while they wait. The stage appears to be completely flat, with a pair of bottomless pits on each side, similar to Final Destination, likely due to its inevitable lack of true use. The stage also has its own unique song that can also be heard in the Sound Test. When Sandbag is thrown out of the stage, it reappears in the center. It should also be noted that there is a "KO" zone for the top of the stage, although Sandbag cannot be killed by flying upwards. This is because the Sandbag in the waiting room is the Sandbag item, only, it doesn't release confetti or items. Characters who can Item Swallow can eat Sandbag, but another will simply appear in the usual location.
The stage can be used in Versus Mode via hacking.