Luigi

Luigi is the younger brother of Mario. He is a playable fighter in every Super Smash Bros. game, but usually has to be unlocked first. Luigi appears in several Mario games, usually having a nearly identical role and set of abilities as Mario. This is reflected in the Super Smash Bros. series, in which Luigi has similar abilities to Mario while retaining some moves of his own.

Super Smash Bros.
In the first Super Smash Bros., Luigi is one of the four unlockable characters. He can be unlocked by completing Break the Targets with all eight starter characters, followed by beating him on the Peach Castle stage. Despite being a locked character, Luigi always appears alongside Mario on Stage 4 of 1P Game and the How to Play tutorial. Luigi weighs 100 units just like Mario.

Luigi is one of the slowest characters, on the ground and in the air (tied with Ness for the slowest running speed and the slowest air speed), as well as one of the lowest falling speeds. Luigi's attacks are either weaker than Mario's, or they deal the exact same damage. Keeping with his distinct gameplay in the Mario series, Luigi also has the lowest traction of any character, but has the highest jumps. Luigi's moves are mostly copied from Mario, though his copied moves have their distinctions.

Super Smash Bros. Melee
In Super Smash Bros. Melee, Luigi returns as an unlockable character. Many of Luigi's moves were changed, increasing his distinction from Mario. Luigi's attack speed has majorly improved, and many of his attacks are now stronger than Mario's. Luigi has become faster on the ground, in exchange for a lower air speed. In addition, his taunt, returning from Super Smash Bros., is now a meteor smash when used against opponents on or near the ledge. Luigi also gains a distinct side special move, Green Missile, in which Luigi launches himself head-first into opponents. Unlike Mario, Luigi cannot Wall Jump.

He can be unlocked in Adventure mode by either finishing Mushroom Kingdom with the seconds value on the timer being a 2 (ex. XX:X2XX), likely a reference to him being second player in several Super Mario series games, or by playing 800 matches in VS. Mode. If the former requirement is met, Luigi takes over Mario's place in the following stage, which is also named Mushroom Kingdom; before the stage starts, a cutscene is shown in which Mario is about to jump onto the roof of Peach's Castle, but Luigi jumps on Mario, who then falls into the water. Later, once Adventure mode is completed, the player's fighter is taken to Mushroom Kingdom II stage to fight Luigi, who can be unlocked from being defeated. Luigi retains his physics from the previous installment, having the lowest traction, but has the second highest jump height, which is now surpassed by Falco.

Additionally, in Adventure mode, once Luigi has been unlocked, his metal counterpart assists Metal Mario on the Battlefield stage. There are four trophies of Luigi, one of them being Vacuum Luigi, which is based on his appearance in Luigi's Mansion.

Super Smash Bros. Brawl
In Super Smash Bros. Brawl, Luigi appears as an unlockable character once more. To unlock him, the player must either play 22 Brawl matches, clear Classic mode without using a continue, or have him join the party in The Subspace Emissary by clearing Subspace (Part 1); with any of the former two methods, Luigi must be defeated on Luigi's Mansion to be unlocked. For this game, Luigi's appearance has been updated to reflect his current design, and his voice clips use his distinct voice, rather than being Mario's voice clips at a higher pitch like in the previous games. Once again, a few of Luigi's animations were changed to make him less identical to Mario. Like many other characters, Luigi's damage output was decreased from Melee; despite this, his attacks remain stronger than Mario's.

For this game, Luigi weights 97 units, making him lighter than Mario. He is also one of the few characters that is able to crawl. While few of Luigi's moves are changed in this installment, his Final Smash is Negative Zone.

The Subspace Emissary
Luigi first appears where he pretends to threaten and attack on-coming Waddle Dees. They are harmless and make no move to attack him, but he is frightened by them nonetheless. From behind, he is attacked by King Dedede, who slams Luigi with his mallet, sending him flying into the air. After he comes back down, Luigi becomes a trophy. King Dedede places him on the road as bait for Wario, who is coming down the road. Wario takes the bait, and King Dedede manages to steal Luigi along with the rescued princess and Ness.

Later, Dedede places a special brooch on Luigi and the others. When Tabuu transforms everybody else into trophies, the brooches, which were revealed to be timer-based revival tools, turn Luigi and Ness back into living beings. Luigi and Ness then revive King Dedede. The unlikely trio set off to help out the others in Subspace. Luigi, along with Ness, then watch King Dedede battle Bowser, and later help him convince Wario to join them. After they turn the trophies back to normal, they all face off against Tabuu.

Super Smash Bros. for Nintendo 3DS / Wii U
Luigi appears as a playable character in Super Smash Bros. for Nintendo 3DS and Super Smash Bros. for Wii U, both of which are the only games where he is a default character. None of his moves have been changed from the previous game with the exception of his down throw, which is now a Ground Pound instead of a body slam; and Final Smash, which is now Poltergust 5000. Luigi now also scuttles during his jumping animation, making him more closely resemble his depiction in the main Mario franchise. Luigi's damage output has been lowered overall, but in exchange, his mobility is faster.

In this game, Luigi can use equipment to boost his stats at the cost of others. In addition to generic badges, Luigi, like Mario, can wear certain additional equipment such as shoes (speed), overalls (defense), and gloves (attack). Finally, Luigi can use alternate special moves, which function differently than the base moves.

Super Smash Bros. Ultimate
Luigi returns as an unlockable playable character in Super Smash Bros. Ultimate. He has a new running animation, which is very similar to his running animation in Luigi's Mansion. Like Mario, Luigi also receives a new walking animation. Aside from this, a few of his moves have changed, such as his up tilt and forward tilt. The former is an uppercut that goes straight upwards instead of a spinning uppercut (in the original Super Smash Bros.) or a "paw swipe" with his fists (in subsequent games), while the latter is now a side kick instead of a roundhouse kick. Luigi also now uses his new Poltergust G-00 for his grab and throws. The Poltergust G-00 functions as a tether grab, and can be used in midair. Luigi's forward and back throws involve him slamming the opponent in multiple directions, while his up throw has him eject foes directly from the Poltergust G-00. Luigi also uses the Poltergust G-00 in his Final Smash. Luigi's up smash is nicknamed the Lead Headbutt, while his standard air is the Luigi Kick.

Luigi benefits from universal changes: his mobility has been made faster, no longer being below-average; his short hop timing and landing lag in his aerials are reduced, making them faster; he can directionally air dodge once again, improving his recovery; and he can use any ground attack out of a run and any aerial attack while holding onto ladders. Luigi's traction has been majorly improved, no longer being the lowest in the game, and is more in line with Mario's. Luigi's forward tilt and dash attack both deal more damage, his forward smash deals more knockback, and his down smash's clean hit is more likely to connect. His down tilt deals less damage, in exchange for having less ending lag.

Luigi appears in Simon's debut trailer, Vampire Killer, where he is walking through Dracula's Castle with his Poltergust while terrified of his surroundings. He attempts to ward off various approaching mummies with his Poltergust's flashlight, eventually hitting one of the mummies in the face with a plunger, which sticks for a few seconds before causing the Mummy to pursue Luigi in a rage, forcing him to flee. He then exits the door into another room, only to find a moving Medusa bust with glowing eyes, causing him to flee again before tripping and landing on his posterior. He then gets back up and looks up to see Death, who kills him with his Scythe as he is screaming. Death is then ambushed and warded off by Simon. At the end of the trailer, Luigi's soul attempts to reunite with his corpse, but as he does so, Carmilla's mask appears in the window next to him, causing him to scream.

Luigi briefly appears in Piranha Plant's reveal trailer, where he is seen dazed alongside a group of Yoshis.

Luigi is unlocked as the 33rd character to be unlocked via playing VS matches, completing Classic Mode as Mario or anyone within his unlock tree, being the fifth character in Mario's unlock tree, or getting him to join the player's party in World of Light.

As with several other returning characters, Luigi's victory theme, which is the orchestral arrangement of the level clear theme from Super Mario Bros. (and is shared with Mario, Dr. Mario and Peach, and in this game, Daisy) has been slightly shortened and sped up compared to the previous installments.