Mii

The Mii is a customizable player avatar that has become a staple of Nintendo games and systems since its introduction in 2006. The Miis were originally introduced and associated with the Wii system (their name being "me" with the same alternate spelling used for the Wii), and since then Miis have also been used for the 3DS and the Wii U. They have been primarily featured in Nintendo's casual first-party titles, and there are also features which allow Miis from other systems to visit through the Nintendo Wi-Fi Connection.

System Applications

Wii

The Miis are featured in the Mii Channel. This is where players can create their own Miis and showcase them within the Mii Plaza. The maximum amount of Miis is 100. The Mii Parade feature could be used to see other people's Miis. Miis also play roles in other channels, such as the Check Mii Out Channel, where Miis can be rated by others.

Miis could also be used to a limited extent in certain Nintendo DS games. Personal Trainer: Walking used Miis that could be either transferred from a Wii's Mii Channel or created within the game.

3DS

The 3DS has a Mii Maker application where Miis can be created, viewed and sent or received to others. This Mii Maker has an optional advanced method where the 3DS's camera will take a picture of the player's face, and the system will try to form a Mii matching the face. Miis could also be transferred from the Wii to the 3DS.

Miis are further personalized in this game, as the player can attach a quote to the character and list their favorite game. There is also a new, separate Mii Plaza app where the player can play minigames with visiting Miis who arrive through StreetPass. The minigames include Puzzle Swap and the RPG-like Find Mii.

In-Game Appearances

Miis have made a variety of appearances since their debut. While they are playable in some games and in other cases are worked into crowds or other minor appearances, some games merely use the Miis as icons for save files or features such as the Nintendo Wi-Fi Connection and StreetPass. They are primarily used for first and second-party games, but they have also been widely used in third-party games for the Wii and DS, including some playable roles.

Mario Games

• Miis have been used to represent save files in WarioWare: Smooth Moves, Super Mario Galaxy, Super Mario Galaxy 2, Mario Strikers Charged and Super Mario 3D Land. In WarioWare, Miis were also featured in some microgames, and the ending credits had the participants represented as Mii versions of themselves.
• In Dr. Mario Online Rx, the player can replace Dr. Mario with a Mii as the main playable character.
• Miis can be unlocked as playable characters in Mario Kart Wii (by winning the 100cc Special Cup) and Mario Kart 7 (by completing all of the cups with any engine setting). They also make background appearances in various courses within both games. In Wii, they had two different outfits.
• Miis are playable in Mario Super Sluggers. Up to eight Miis could be used, but they could not act as team captain. The Mii was also playable in Mario Sports Mix.
• Miis are playable in the Wii versions of Mario & Sonic at the Olympic Games, Mario & Sonic at the Olympic Winter Games and Mario & Sonic at the London 2012 Olympic Games.
• Miis appear in Mario Party 8, where they are the only characters playable in the Extras Zone, and they all wear Mario-like overalls. They are also normally playable in Fortune Street.
• In Yoshi's Woolly World, there are Yoshi designs based on the default designs for the Mii Brawler, Mii Gunner and Mii Swordfighter from the Super Smash Bros. games. They are unlocked by scanning their respective amiibos.

Super Smash Bros.

In Super Smash Bros. for Nintendo 3DS/Wii U and Super Smash Bros. Ultimate, Miis are featured as playable characters, known as Mii Fighters. These Miis can be imported from the system's Mii Maker or created within the game. There are three different types of Mii Fighters with different specialties: Mii Brawlers use hand-to-hand combat, Mii Swordfighters use swords to attack, and Mii Gunners have blaster arms to shoot enemies with. These fighters are all customizable, as the player can choose their special moves and can equip them with a number of custom parts that can affect their stats in different ways to allow for variety in how they play.

In the 3DS/Wii U Smash Bros., all three types of Mii Fighters are also present as enemies in Multi-Man Smash as the Fighting Mii Team, acting as a successor to the Fighting Polygon/Wireframe/Alloy Teams present in previous Smash games. They continue to act as opponents in the similar Mob Smash games of Ultimate.

In Ultimate, they are technically unlockable characters, and the three types each have their own fighter slot. However, each type can be unlocked simply by creating a character of that type in the Mii Fighter menu. Alternatively, a generic version of each Mii Fighter type is unlocked by finding and defeating them on Adventure Mode's map. That is also how each of them are unlocked for Adventure Mode, which only has characters available who are unlocked within that mode. Within Adventure Mode, the Mii Swordfighter is found by the Light Realm's village area, the Mii Gunner is located at the island area, and the Mii Brawler appears in the Sacred Land area of the Dark Realm after solving a torch puzzle. In this game, Mii Fighters are the only characters unavailable for Classic Mode.

In the 3DS/Wii U game, each variation of the Mii Fighter has two unlockable trophy, and there is also a trophy for the Fighting Mii Team, while the Wii U version also has trophies for each of their Final Smashes. In Ultimate, each of the Mii Fighters has their own Fighter Spirit that can be purchased through the Vault's shop.

Other Wii Games

• Miis are the primary playable characters in Wii Sports, Wii Sports Resort, Wii Play, Wii Play Motion, 'Wii Fit, Wii Fit Plus, Wii Party and Wii Music.
• In Metroid Prime 3: Corruption, Miis were used to represent save files, and bobblehead versions of Miis could be bought within the game to decorate Samus's Gunship, with the bobblehead wearing the Varia Suit. Miis were also used for save files of the other games in Metroid Prime Trilogy.
• In My Pokémon Ranch, Miis were used for the player and non-playable characters, including the original character Hayley.
• In Animal Crossing: City Folk, it is possible to play a mask of the player's Mii that can be worn by the player character.
• In Big Brain Academy: Wii Degree, Miis are used for save files, and they also appear in the game as students.
• Miis can be used in the WiiWare version of Magnetica.

Other 3DS Games

• Miis are featured in Pilotwings Resort as playable characters.
• In Pokémon Rumble Blast, a Mii is used to represent the player character.
• Miis are playable in Tetris: Axis.
• Tomodachi Collection and Tomodachi Life are Nintendo life simulation games featuring the Mii characters.