Stage legality

In competitive play, a banned stage is a stage that is not eligible for tournament play. A stage may be banned for a variety of reasons, such as:
 * Poor matchup balance due to providing an extreme advantage for certain characters, such as allowing excessive camping or infinite chaingrabbing.
 * Powerful stage hazards that easily KO players knocked into them, or force them to give up the advantage to avoid them.
 * Allowing players to exploit glitches or bugs.
 * Possessing "caves of life", certain sections of the stage that allow characters to survive much longer than realistically possible under normal circumstances, which creates an over-centralization around teching
 * Possessing walk-off blast lines and walls. Both conditions create unreasonably powerful camping positions and potentially allow easy zero-to-deaths that wouldn't occur in a competitive environment; in addition, walk-off blast lines completely eliminate offstage play, due to the main stage taking up the entire width of the fight.
 * Drastically altering gameplay and strategies needed to win,

Below is a list of banned stages in Super Smash Flash and Super Smash Flash 2.

List of banned stages in Super Smash Flash
This is the current ban list for Super Smash Flash, as of May 23, 2015.

List of banned stages in Super Smash Flash 2
This is the current list of banned stages for Super Smash Flash 2 Beta, as of July 1, 2017. There are three levels of stage bans: Note that this banlist only covers singles, as the competitive doubles metagame is virtually nonexistent at this time. It should be noted that all these stages are banned regardless of the stage hazard, unless stated otherwise.
 * Banned: Stages that are banned in all forms of competitive play.
 * Banned in back room list: Stages that are banned from the official Backroom stage list, but are sometimes legal in experimental rulesets.
 * Banned in back room online list: Stages that are banned from the official online Backroom stage list, but are legal in offline tournaments and experimental online rulesets.