Rules and game settings that are widely accepted in the competitive community for use in professional Smash tournaments are considered to be within the bounds of what is tournament legal. Some multiplayer game elements, such as items and certain stages, are believed to cause gameplay to become degenerate or unfair in the context of tournament level competition. Because of this, these elements are not considered tournament legal, and are "illegal" in competitions. For example, the Melee stage Big Blue is not accepted as tournament legal and is a banned stage. The most widely accepted sets of rules for Melee and Brawl are those proposed by the Smash World Forum's Back Room (the SBR rulesets), while the original Super Smash Bros. does not have an official SBR ruleset.
See the following accepted rulesets: