The Japanese trailer introducing Mega Man in Super Smash Bros. for 3DS and Wii U has "Clash Man" (the original Japanese name) instead of "Crash Man" (the English name) in the Japanese commercial, despite being changed to Crash Man in Japan.

All of the characters in the game were chosen at the start of development. This means Geninja was chosen before Pokemon X & Y was released, and that its inclusion was not because of its popularity.

There was an open slot for a new Pokémon character, and the team began discussing who to put in it, eventually settling on Greninja. All the reference material they had for Greninja were simply drawings at that point. Sakurai went home the same day he received the Greninja reference material and stayed up until midnight to do the motion capture for the character.

According to series director Masahiro Sakurai, Dr. Mario, Dark Pit and Lucina were originally considered to be alternate costumes for Mario, Pit and Marth respectively, but were eventually changed to be their own separate characters with slight differences in their movesets from the three.

According to Masahiro Sakurai, the reason the Ice Climbers were cut from the roster is because of 3DS hardware limitations. He also states that he didn't want to add them exclusively to the Wii U roster to avoid there being considerable differences between the two versions.

Sometimes when Luigi uses the green missile and he hits a wall, he will stick to the wall.

The song that plays on the results screen after a fight is the character select theme from the first Super Smash Bros.

The Pokemon Trainer trophy makes reference to the first opening theme music from the English dub of the Pokémon anime.

"Pop quiz! What do Misty, Brock, Cynthia, Iris, and Ash all have in common? That's right"”they're all Pokémon Trainers! This Pokémon Master in the making is the same. Back in Super Smash Bros. Brawl, he fought to be the very best"”like no one ever was. To smash them was his real test"”to launch them was his cause!"

Having specific character pairs fight each other in a normal 1v1 Smash fight results in personalized victory screens:

• Fox beats Falco:"Better luck next time, Falco."
• Falco beats Fox: "You're off your game, Fox."
• Male Robin beats Lucina: "Lucina, I hope I didn't hurt you."
• Female Robin beats Lucina: "How can you protect Chrom if you can't protect yourself?"
• Lucina beats Marth: "This is the Hero-King?"
• Lucina beats Ike: "And they call you the Radiant Hero?"
• Palutena beats Pit:"Oh, so sorry about that, Pit."
• Palutena beats Dark Pit: "Poor little Pittoo."
• Dark Pit beats Pit: "Where's your goddess now?"

Holding down the L button when selecting the Boxing Ring stage will change the design of the ring from Punch Out oriented to Super Smash Bros. oriented.

According to the game's director, Masahiro Sakurai, the reason for Sheik and Zero Suit Samus appearing as separate characters is due to the limitations of the 3DS not being able to have them transform from their respective characters. This option was made because Sakurai wanted both versions of the game to have same roster.

After obtaining every Mii outfit, the game will give you a notification reading, "Collected every type of custom outfit! Your body is ready!" A reference to Nintendo of America CEO Reggie Fils-Aime's popular quote from E3 2007, "My body is ready!", which has since become a popular meme.

As the Villager does their final smash attack, Tom Nook actually throws furniture into the house being built. There's even a chance he will throw in a Triforce from The Legend of Zelda, as it can be collected in some of the Animal Crossing games as a house decoration.

During Palutena's Temple, Palutena, Viridi and other characters from Kid Icarus: Uprising will converse with Pit about the character you're fighting against. This is similar to how Snake in Super Smash Bros. Brawl could use his codec to converse with either Colonel Campbell, Mei Ling, or Otacon when on Shadow Moses Island.

Lucina is the only unlockable character who was officially revealed prior to the game's 3DS release and is the first female unlockable character in the Super Smash Bros. series.

When initiating Palutena's Guidance as Pit when fighting against Shulk, Pit will quote several popular phrases used in Xenoblade Chronicles, such as "What a bunch'a jokers" and "Let's not lose our 'eads, though."

When initiating Palutena's Guidance as Pit when fighting against a Mii Gunner, the Nintendo Wii's code name "Revolution" is referenced when Viridi refers to the Mii Gunner's motion controlled arm cannon as "revolutionary".

The description for the "Souflee" trophy from Kid Icarus reads, "We could tell you it's a cake, but that would be a lie". This is a reference to running gag through the first Portal game, stating that "the cake is a lie".

According to Masahiro Sakurai, the Orbital Gate Assault stage took one year to create.

Unlike all previous entries in the Smash Bros. series, Jigglypuff uses the standard Pokémon palette as apposed to her shiny palette. This is most noticeable in her eye color.

While Xander Mobus, the game's announcer, recorded a shout of the game's name (much like Super Smash Bros. Melee), it went entirely unused in the final game's release.