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. While tournament rulesets are generally accepted by most major tournaments, they are not set in stone. There may be minor differences between them, and some local tournaments may make their own ruleset completely different from the standard to meet their specific goals. Rulesets are also subject to change at any point in an effort to address a loophole or account for a new gameplay discovery.
See the following accepted rulesets: