Online play

Online play, also known as network play or netplay, is the act of playing games in the  series with other players via the Internet. Thus far, Super Smash Bros. Brawl, both versions of Super Smash Bros. 4, and Super Smash Bros. Ultimate have had netplay officially supported by Nintendo; while released without native netplay capabilities, modern methods exist for playing both Smash 64 and Melee online.

In Super Smash Bros.

 * See also: Project64k

The Nintendo 64 does not natively support online play, though the idea was explored as part of the add-on. As such, online play for Smash 64 is accomplished through the use of emulators, such as Project64k. Owing to the lower system requirements of Nintendo 64 emulators and the rather fragmented community surrounding Smash 64, netplay is among the most common ways to play the game in the current scene. Initially, netplay was achieved via servers such as Smash FU and The Galaxy, but the community has since changed to mostly using peer-to-peer connections.

In Super Smash Bros. Melee

 * See also: Project Slippi

While the Nintendo GameCube does have limited support for internet connectivity with appropriate adapters, Melee was released prior to the official release of these adapters, and as such, it does not natively support online play. Like Smash 64, online play for Melee is generally accomplished through emulators, particularly Project Slippi.

Prior to Slippi and Dolphin featuring netplay functionality, experimental online play was previously performed by a variety of tunneling softwares that could directly connect GameCube consoles to one another, such as via or exploits in  for the GameCube. These methods, however, were difficult to set up, required extensive knowledge of the software on hand and networking protocols, and required both players to be using the same version of Melee. Matches themselves often had desyncs, with items notably being implicated.

Online play later experienced mainstream popularity with the GameCube and Wii emulator Dolphin, which allowed for considerably easier connectivity between players, as well as being considerably more reliable in terms of synchronisation. Initially holding only niche popularity due to Dolphin's high system requirements, the gradually increasing power of personal computers and improvements to Dolphin's performance has allowed for more Melee players to partake in online play.

In Super Smash Bros. Brawl

 * See also: Nintendo Wi-Fi Connection, Dolphin

The Nintendo Wii was the first Nintendo home console to support online play out of the box, with Nintendo allowing the device to take advantage of the Nintendo Wi-Fi Connection (WFC). As a result, Brawl was the first game in the series to officially support online play, allowing players to fight against either strangers or friends. In addition, gameplay mods for Brawl could also be unofficially played online via this protocol, though all players would need the mod in order to prevent desyncs from occurring.

Upon selecting the Nintendo Wi-Fi menu, the player is given two options: With Friends and With Anyone. With Friends requires inputing Nintendo Wii friend codes to connect with other players for private online games. With Anyone offers three options: Basic Brawl, Team Battle and Spectator Mode. Basic Brawl is meant for 1v1 matches where the rules were based on a mixture of a voting and lottery system. Team Battle is much of the same except for teams. Spectator Mode allows players to watch other online matches without participating. This mode included a betting system where spectators could win rewards for correctly predicting which fighter would win.

Official support for online play in Brawl was ended on May 20, 2014. A variety of methods, however, still allow for Brawl to be played online; replacement WFC servers, primarily Wiimmfi, make WFC mode continue to work just like it used to. The Dolphin emulator also runs Brawl and supports netplay with less latency than WFC.

In Super Smash Bros. 4

 * Main article: Nintendo Network

Like Brawl, both and  natively support online play, this time via the Nintendo Network. The service offers a variety of improvements over Brawl's online play, particularly in regards to options and matchmaking. The overall concept, however, remains the same, with players being able to play against either strangers or friends via the internet. The latest version of the game must be downloaded to access online modes.

As of version 1.1.0, upon entering the Online submenu, the player is given five options: With Anyone, With Friends, Tourney, Conquest, Spectate, and Share. Upon selecting With Anyone, there are two options to choose from: For Fun and For Glory. For Fun is an unranked mode that can be used with any ruleset. For Glory uses a matchmaking system based on Global Smash Power and is restricted to no items, and Ω Form stages only. With Friends functions similarly to Brawl. Tourney is similar to the mode in previous games, except online with occasional tourneys run by Nintendo themselves. This mode went defunct on November 8, 2017 after the discontinuation of Miiverse. Conquest aggregated global wins among specific groups of characters (known as teams) in With Anyone during a limited time, and determined the victor based on the number of wins. Players who backed the winning team would win prizes. The mode was discontinued on January 3, 2019. Share is a server that allowed players to upload content for others to view. Several options in this mode were discontinued on November 8, 2017 after the discontinuation of Miiverse, including uploads to YouTube, sharing snapshots and sharing custom stages. However, sharing replay data and Mii Fighters remained available.

Official support for all online functionality in Smash 4 will end in April 2024, with the discontinuation of online services for the Nintendo 3DS and Wii U consoles.

In Super Smash Bros. Ultimate
Ultimate has native online support much like Brawl and Smash 4. However, this time online play is a paid service as part of. Rather than selecting from modes with specific rules, players can now choose their own preferred rules and the game will attempt to match players with similar desires. Compared to previous games, Ultimate allows for a wider selection of rules when playing with anyone. Just like Smash 4, the latest version of the game must be downloaded to access the online modes for the same reasons.

As of version 4.0.0, upon opening the Online submenu, the player is given four options: Smash, Spectate, Shared Content, or Online Tourney. Upon choosing Smash, there are three options to choose from: Quickplay, Battle Arenas, and Background Matchmaking. Quickplay has the player select Solo or Co-op (local), with a Preferred Rules switch underneath the two options. Preferred rules include the format, time limit, stage, stock count, whether Final Smash Meter is on or off, and which items should be turned on. If a player accrues enough Global Smash Power with a single fighter, the player can use that fighter in Elite Smash: a mode similar to Quickplay where players are only matched with other players in Elite smash. However, the player needs to maintain that GSP count, and will be kicked from Elite smash if they dip below the threshold.

Upon choosing Solo or Co-op, the player(s) can choose their character(s), and are taken to the Online Practice Stage. There they can train with CPU partner(s) while waiting for opponent(s).

If the player(s) choose Background Matchmaking, they can choose Solo or Co-op, their fighters and preferred rules. While waiting for their opponent(s), they can participate in various different modes.

Battle Arenas are a new form of online play for the series, being able to make it visible for all (Public), or for Friends only. Arenas can have a password set, preventing unauthorized players from entering. The type can also be set, for All Skill Levels, Veteran Players, Glorious Smashers, Anything Goes, Playground, amiibo Battle (available after update 3.1.0), Elite Only, and Beginners Only (both available after update 6.0.0).

Many players have opted to use emulation via the yuzu emulator in combination with external video streaming software such as Parsec as a means to play Ultimate online. This has become popular in the wider competitive scene mainly due to the problems faced with the game's native online service, with some top players such as and  using this technique to play.

In competitive play
Online competition has been a fixture of the scene ever since the introduction of network play in Brawl, though serious online tournaments were unheard of until the release of Smash 4 outside of AllisBrawl's ladder playoffs, due to Brawl's notoriously poor online performance and players at the time predominantly playing on poor Wi-Fi connections. The ability to match with players regardless of location makes it an important avenue for players who wish to compete but are either unable or unwilling to travel to large-scale gatherings like tournaments. Like offline tournaments, online tournaments usually have an organizer that oversees the bracket, while having players that are matched friend each other on their respective systems, play their matches, and then report the results to the tournament organizer.

The use of online battles as an outlet for serious competition, however, is controversial. The inherent latency that comes with playing a game online, thus resulting in framerate drops, online desynchronization, and even complete disconnections, makes them significantly less suitable for testing the skills between players, especially for a game that tests players' reaction times in competition like Smash. The need of an internet connection also opens up other issues, such as worse performance if one participant does not have a stable internet connection, and interference or some other form of griefing. These concerns have led the community to prefer offline play whenever possible and disregard most online competition as little more than diversions before 2020. Masahiro Sakurai himself has expressed the opinion that playing any Smash game online is not ideal, feeling the lack of camaraderie from playing against unseen strangers instead of one's friends makes the game less fun. However, the majority of players would still play online to practice, as it allowed them to conveniently play whenever they want, and play far more different players than they would have access to at their locals, being an invaluable source for obtaining matchup experience.

As with many other games, online competition received renewed attention during the COVID-19 pandemic. Starting from the beginning of 2020 and continuing into the end of 2021, nearly all public events and gatherings either put strict regulations on in-person attendance or were cancelled entirely, including most offline Smash tournaments. As such, the community began prioritizing online tournaments, some of which acted as stand-ins for cancelled offline tournaments. While the aforementioned problems with online still persist, the competitive scene has slowly begun to recognize that, given the proper equipment and preparation, online play is a valid method for competition, with many high profile tournaments being online-only and annual circuits integrating online tournaments into their roster for credit towards the finals.

The necessity of unofficial tools to play the older Smash games online resulted in renewed friction between the community and Nintendo, the latter of which openly disapproves of the use of any mods. This came to a head with the cancellation of The Big House Online, the planned online replacement to The Big House 10, in November of 2020, after Nintendo ordered a cease-and-desist of the tournament due to its planned use of Project Slippi for the Melee tournament. Many community members felt that Nintendo's actions were in poor taste during a pandemic that prevented most offline tournaments from occurring, the backlash of which eventually culminated into the #SaveSmash movement.

A player that predominantly plays online is often called a "Wi-Fi Warrior" or Online Warrior. These players have historically had the community doubt their ability to perform as well in an offline environment, due the belief that these players adapted to an online environment that would not have their skills translate to an offline environment without the input lag of online play (or less charitably, believe these players outright exploit the increased input lag and instability of online play in their play styles). Whether this ideology is fair or not is debated, as often these players do perform at a comparable level when they compete offline, and since Brawl, many top players, if not the majority of them, were initially "Wi-Fi Warriors" or players that did play online a significant amount.