Mii

Miis are digital avatars that appear in the Mii Channel, Mii Maker, and Mii Plaza. Miis get their name from the word "me", in the same way that the Wii gets its name from "we". Miis are based off of human beings, and players can design what their Miis look like and use them in compatible games. Shigeru Miyamoto had wanted to create digital avatars for Nintendo systems since the Nintendo Entertainment System and kept trying to create them with every system released, such as the Nintendo 64DD add-on and Nintendo DS. Players can start from scratch or create a Mii from an existing template Mii. Only 100 Miis fit in one Wii console, while each individual Wii Remote can hold 10 Miis. Miis can also be created on the Nintendo 3DS and the Wii U. They can be created either from scratch or from a photo, using Mii Maker, where they can be edited as well. Also, Miis can be made into QR Codes, to be scanned from another Nintendo 3DS, or a Wii U. Each 3DS system can have up to 100 Miis, and each Wii U system can have up to 3000 Miis.

WarioWare: Smooth Moves
Miis appeared with Wario in WarioWare: Smooth Moves. In this game, the Miis are used as personal files for the players, and are used in several microgames and in Multiplayer Mode to represent those playing. One of the multiplayer modes starring the Miis is very similar to the minigame Balloon Bang. The creators of the game also appeared in the credits as Miis, but were wearing costumes unable to be used by the player, such as Mario overalls.

WarioWare D.I.Y.
In the microgame Tightrope (one of 9-Volt's microgames), the purpose of the game is to prevent a male Mii from falling while holding a pole and crossing a tightrope. The Mii is leaning to the left, as if he's about to fall. The player needs to tap the right side of the Wii Balance Board at the bottom right corner to give the Mii balance. The Mii then leans to right and the player has to tap the left side of the Wii Balance Board. If the player taps the side that the Mii is leaning to (e.g. tapping the left side while the Mii is leaning to the left and vice versa), the Mii falls to his doom. If the player takes too long to choose, the Mii also falls. If the player prevents the Mii from falling, the game is won. However, if the Mii falls, the game ends in a loss.

This microgame is based on the Tightrope Walk minigame in Wii Fit.

Mario Party 8
In Mario Party 8, Miis are playable characters and are sometimes seen in the background of mini-games, which are only playable in the "Extras" section. The Miis in this game wear overalls, gloves, and shoes like the Mario brothers. The shirt they wear depends on the player's color, not their favorite color. Miis are also available to personalize players' file.

Mario & Sonic at the Olympic Games
In Mario & Sonic at the Olympic Games, Miis are playable characters, just as capable of competing as the characters from the Mario and Sonic the Hedgehog series. Their stats are all five out of ten. In this game, the Miis have no voices and are simply called "Mii" during events.

Mario & Sonic at the Olympic Winter Games
Miis return in Mario & Sonic at the Olympic Winter Games. This time, Miis can be customized to wear different clothes and accessories. Unlike the last game, the stats differ depending on the gear. They can even wear different costumes of the playable characters in the game. Some of the bosses from Festival Mode also give off their costumes for Miis to wear once defeated.

Mario & Sonic at the London 2012 Olympic Games
Miis appear again as playable in Mario & Sonic at the London 2012 Olympic Games. As in the previous installment, players can customize their Miis with accessories and wear various costumes. These are earned when playing in the Olympic events and the London Party mode.

Mario & Sonic at the Sochi 2014 Winter Olympic Games
Just like in the 2 previous installment on the Wii, the player can use their Miis as characters. As with the previous 2 installments Miis are customizable, however this time around Miis will actually show what type their clothing makes them.

Dr. Mario Online Rx
In Dr. Mario Online Rx, Miis are able to replace Dr. Mario as the playable character. Here, they must maneuver Megavitamins tossed into a glass jar in order to destroy the Viruses. In order for a virus to be destroyed, it must be connected to at least one Megavitamin of the same color. Unlike Doctor Mario, Miis speak. Miis can tell the player how many minutes have passed and how many capsules they've thrown.

Mario Kart Wii
In Mario Kart Wii, Miis first appear as background characters, found in various race courses. They also appear in posters, and other signs, as seen in Coconut Mall. Later in the game, Miis can be unlocked as playable characters. There are two outfits available for Miis, and both outfits must be unlocked. The first one (Outfit A), which is available when the Mii character option is unlocked, is a plain racing suit of the Mii's favorite color. The other (Outfit B), depends on the gender of the Mii. If the Mii is male, he receives a Mario outfit of his color (if the Mii's outfit is green, the outfit will look similar to that of Luigi), and if the Mii is female, she receives a Princess Peach outfit of her color.

A kart's color scheme changes depending on the Mii's gender (primarily blue for males, primarily pink for females). Miis also receive generic voices in Mario Kart Wii, which has a unique voice for each gender and favorite color combination. There are four different voice recordings for both male and female Miis, which changes pitch, depending on which size class the Mii is in (if the Mii is large-sized, the voice will be lower than normal, and if the Mii is small-sized, the voice will be higher than normal). The weight class for the Mii driver depends on the size in the Mii Channel. Notably, when the player plays as a Mii, statues and pictures in various courses, such as Moonview Highway, Luigi Circuit, Coconut Mall, and Daisy Circuit, will replace the character heads with that of Mii heads, consisting of the Miis saved on a players Wii console.

A Mii can be either a large, medium, or small character, depending on his or her height and weight.

Originally, a Mii Outfit C was going to be added, but was cut from the final version of the game.

Mario Kart 7
Miis later appear as racing participants in the Nintendo 3DS title, Mario Kart 7. They can be unlocked by completing all the Grand Prix cups on any engine class. Unlike in Mario Kart Wii, however, all the Miis get the same stat boosts and are the same weight (in this case, medium, as Mario and Luigi), which are at around average levels. Miis also appear as audiences in several courses. Also, the Miis have two of their own courses, Wuhu Loop & Maka Wuhu, as well as their own battle course, Wuhu Town. All of these courses come from the game Wii Sports Resort.

Stats

 * Class: Medium
 * Speed: 3.5
 * Acceleration: 3
 * Weight: 3.25
 * Handling: 2.75
 * Off-Road: 3.75

Mario Kart 8
Miis have been confirmed to appear as playable characters in Mario Kart 8.

Mario Super Sluggers
Miis are playable characters in the game Mario Super Sluggers. Miis cannot be chosen as team captains, but up to 8 Mii's can be used. Mii stats in this game are 6/10 and chemistry with other characters is based solely on favorite color (excluding Diddy Kong, Funky Kong and Toadsworth) e.g. red Miis have chemistry with Mario, green Miis have chemistry with Luigi (but oddly, not Yoshi; Yoshi has good chemistry with light green Miis instead), pink with Peach, etc. Miis of the same color but opposite genders also have chemistry with each other. Also, they possess the quick throw ability, which allows the players to make faster throws to teammates.

All male Miis are right-handed batters in this game, while the female Miis are left-handed batters. However, both genders are right-handed fielders. They don't speak in the game.

Mario Sports Mix
Miis are one of the nineteen playable participants in Mario Sports Mix. They're the all-rounder (All-Around) type, with Mario, Luigi, Yoshi and Ninja. Despite their height and width, they all receive the same stats: 3/5 in every stat. The color of their outfits depend on their favorite color and their clothing depends on their gender; male Miis receive a sporting outfit, while female Miis receive a skirt. Miis are also seen in the audience.

Their special ability is very similar to Mario's special ability; they throw the object into a goal which can be blocked by a struggle of the opponent. In dodgeball, the shot causes a damage radius that hits anyone inside the radius. Miis receive voices in this game, a quality somewhat rare in games they appear playable in.

On a side note, Miis never appear as opponents in tournaments.

A real life Mii made an appearance in various commercials to help promote the game in North America. They are sports anchors during these commercials under the names Mii-guel and Mii-chelle, showing gameplay footage to the players in various segments like the Super Top 3 Show, for example. Also, they announce a press conference on the day of the game's release, asking questions for Mario.

Fortune Street
Miis appear as playable characters from the beginning. If the player decides to start a solo profile, the he or she then has to choose a Mii for their profile. The only characters the player can use in solo mode is their Miis. The player can unlock clothes to dess up their Mii in the Dressing Room. Miis don't say anything to the other players. The color of the Mii's shop depends on the color of the Mii which is replaced by two of the Mii's opponents talking to each other; However, if one or more Miis have the same color, they will be changed, depending upon order as chosen.

Mario Tennis Open
Miis also appear in the Nintendo 3DS title Mario Tennis Open as playable characters. The player can dress up Miis in different costumes that can be bought in the clubhouse to give them different stats.

New Super Mario Bros. U
Miis make their first appearance in New Super Mario Bros. U as playable characters only in the Boost Rush, Challenge, and Coin Battle Modes. The Miis can now use the same abilities as Mario, Luigi, Blue Toad, and Yellow Toad, as they can use power-ups like the Super Acorn and Fire Flower. If the Miis are selected as either P1, P2, P3, or P4, each will be colored with the overalls of Mario, Luigi, Wario, and a coloration similar to Luigi's blue alternate costume from the Super Smash Bros. series. Randomly generated Miis appear in various places of the background in Boost Rush Mode. Miis have the ability to play with or without a hat and female ones wear shorter overalls, revealing black socks underneath. In this game, the Miis reuse their voices from Mario Kart 7.

In New Super Luigi U, the player's Mii can also be used if a trick is done on the Flying Squirrel Ovation level in Superstar Road which has the player holding down on the / or  on the  while selecting the level (if this trick is used on a different level in the game, the player plays as Nabbit instead).

Miis are also able to post comments online about a level they have played.

Super Mario 3D World
Miis return in Super Mario 3D World. Here, they serve as representatives of people who send messages and ghost data through Miiverse. The player can spot them standing around on the world map, where their messages pop up when Mario and co. get close. Players can also opt to send out ghost data on completed levels, and try to beat the time records on other people's ghost data as well. The player can race up to three Miis at once, in an attempt to beat their record. In the game, the Miis appear in Sprixie costumes corresponding to their favorite color, and are shown to mimic the exact movement of the person using the Mii, (using Luigi's Scuttle, running on all fours like the Cat Suit, etc.) Miis also have voices in the game while doing a type of move.

Mario Golf: World Tour
Miis are set to appear in Mario Golf: World Tour. The player is able to travel around a hub area as their Mii. Like in Mario Tennis Open, the player can customize their Mii with various clothing and clubs to alter their stats.

Other Appearances
Miis also appear in games such as Donkey Kong Barrel Blast, and Mario Strikers Charged to represent the player, similar to an avatar. In Super Mario Galaxy and its sequel, players can personalize their files with Miis. This has also been done with other non-Mario related games. In Super Smash Bros. Brawl, players can use their Mii on Wi-Fi to represent themselves.

Miis appear along with Mario, Luigi, Blue Toad, and Yellow Toad in the Wii U experience game New Super Mario Bros. Mii. If the Miis are selected as either P1, P2, P3, or P4, each will be colored with the overalls of Mario, Luigi, Wario, and Mario's colors from Mario Bros., respectively, just like New Super Mario Bros. U.

Check Mii Out Channel
One of the channels in the Wii is the Check Mii Out Channel (or the Mii Contest Channel in the PAL region), where Nintendo holds contests to see who can create the Mii that looks the most like a certain person, for example a few contests had players to create Miis that looked like the Tooth Fairy, or another that even had players to create a Mii of a Gingerbread Man. Some of the contests have been Mario related. Here is a list of them:
 * Mario, without his hat, was the first contest in the Check Mii Out Channel.
 * Luigi, without his hat, was a later contest.
 * Another contest had players create Princess Peach.
 * Another contest was "Someone like Mario, but a little different".
 * One contest focused on Bee Mario.
 * A contest focused on "someone that helps a princess", which makes a reference to Mario and Link.
 * One contest was "Wario without his hat".

Trivia

 * Miis receive voices for the first time in Mario Kart Wii, not counting small background noises that they first made in Wii Play ' s Shooting Range event.
 * If the player goes on the internet browser on the Wii U from the home menu and the curtains are closed, the spotlights shine on the curtains for about 15 seconds, then the current user's Mii comes up and start doing different activities. They include singing, juggling, dancing with a baton, dancing with a candy cane as if it is a baton, doing a magic trick, and sleeping.