Doubles

Doubles refers to the 2 versus 2 part of a tournament, also referred to as "teams". Doubles requires a different strategy, namely teamwork, to defeat opponents. Although there are as many ways to play as there are players, several things remain constant: those who work together to attack and destroy their enemies stand a greater chance of winning, while those who separate to take on their opponents alone are easier to defeat as individuals by attacking them two-on-one. Strength in singles playing style does not necessarily translate into strength in doubles; the strongest team is the winner, not the pair of strongest individuals.

Doubles tournament rules
In general, rules for singles tournaments also apply to doubles except where otherwise noted. See tournament legal for all tournament rules.

All games

 * Team Attack is enabled. This setting is preferred as it prevents abusive strategies and requires greater coordination between teammates.
 * Sharing stocks is allowed.
 * Legal stages may differ from singles, particularly in Smash 64 and Melee.
 * If the clock expires and the total number of stocks of each team is equal, use the sum of the final percentage of the players on each team as the tiebreaker; whichever team has a lower sum wins. (A player who has been eliminated has 0 stocks and 0%.)

Super Smash Bros. Melee

 * Fountain of Dreams is banned in doubles play. This is due to the stage's small size, as well as the water reflections causing lag issues.
 * is a starter stage, unlike in singles, joining the four remaining singles stages (, Dream Land, Pokémon Stadium, and Yoshi's Story) as starter stages. Other stages normally banned in singles may be occasionally used as counterpick stages (such as Kongo Jungle).

Super Smash Bros. Brawl

 * Double Meta Knight is banned: two players on the same team cannot both use . This rule became commonplace in 2012, following Apex 2012, in which all four players in grand finals used Meta Knight; prior to 2012, double Meta was legal in tournament play.
 * If time runs out and either player on a team breaks their edge grab limit, their team loses. If players on both teams exceed the limit this rule is ignored.
 * It may be requested by either team to change team colours in order to prevent any unnecessary confusion, if one of the players is, , or.

Super Smash Bros. 4

 * Instead of the 2 stock and 6-minute time limit format in Singles, Doubles are played with 3 stocks and an 8-minute time limit.
 * Like the Double Meta Knight ban in Brawl, Double Cloud is banned in doubles even with at least one Cloud as a teammate. The effectiveness became a notoriety for the community which resulted Smash 4 tournaments,, , , , and banning Cloud in doubles.

Super Smash Bros. Ultimate

 * Due to a glitch regarding 's Rebellion Gauge, Joker and were banned from being paired together in doubles at Glitch 7. This glitch has since been fixed.

Differences from singles
The doubles metagame differs considerably from singles, and places greater emphasis on teamwork and synergy, rather than individual skill; two players who team and practice regularly will generally be favored to win over two players who are individually stronger but have never teamed before. is not known as a tournament favorite in singles, but practices extensively with his brother in doubles; the two form one of the strongest doubles teams of Melee, and the two have placed in the top three at almost every doubles event. SFAT and PewPewU are another static doubles team famous for their teamwork, and the two have earned consistent top placings in doubles tournaments.

The relative strengths of certain characters can be significantly different in the doubles scene. The Ice Climbers are high-tier in Melee and top-tier in Brawl, but are considered nonviable in doubles play; this is because their wobbling strategy is almost impossible to pull off safely, for an opponent can easily interrupt a wobble to save their teammate. in Brawl is also regarded as significantly weaker in doubles, since one of his main strengths, his ability to camp with lasers, is less effective in a field with four players. On the other hand, in Brawl, is considered a borderline viable character in singles, but is known as one of the best characters in the game in doubles. Wario's strong aerial mobility and attacks allow him to navigate through the more chaotic battleground with ease, and his forward throw and down are two of the best setup throws in the game, granting his teammate an easy followup attack that often leads to a KO. In general, a much larger number of characters are considered viable in doubles, since two different characters can mitigate each other's weaknesses, and the greater emphasis on teamwork means that singles viability is less valued. In Smash 4, Cloud is a popular character in singles that becomes dominating in doubles. Cloud's massive disjoints and good frame data allow him to control the stage with his aerials, while his Limit Break specials can finish off stocks with little effort. Furthermore, Cloud's average recovery can be helped or covered with a teammate's attack, allowing him to take advantage of his survivability. In 2018, some tournaments and scenes banned the usage of Cloud, either individually or in tandem, due to his dominant results.

Numerous unique strategies and "gimmicks" have become popular in the doubles metagame, many of which utilize strategies that are unique to the 2v2 format. For example, players can use Mr. Game & Watch's Oil Panic or 's Pocket to collect a teammate's projectiles and use them as a powerful attack against opponents. Ness and Lucas can also use their PSI Magnets to collect easy healing from a teammate's energy projectiles. The Anubis Combo was a popular strategy in Brawl that utilized the unique nature of 's aura to its advantage, where an extremely powerful Lucario fought the enemy team 1v2 for most of the match.