Amiibo

amiibo (アミーボ) are a line of interactive figurines available for usage with compatible software for Nintendo platforms beginning with the Wii U and Nintendo 3DS.

Function
amiibo are a line of collectable figures or cards featuring numerous Nintendo characters from various franchises. The series debuted on November 21st, 2014 with the Super Smash Bros. for Nintendo 3DS and Wii U line of amiibo. Using near field communication via the sensor within the Wii U GamePad, Nintendo 3DS amiibo adapter platform, New Nintendo 3DS touch screen, or Nintendo Switch JoyCon, scanning an amiibo unlocks special content in numerous Nintendo video games. The bonus each amiibo unlocks depends on the game which they are scanned in. Some only unlock generic bonuses in game while others may unlock unique content. Several amiibo also have the ability to save special data within the amiibo's internal storage.

Super Smash Bros. Series

 * Marth
 * Ike
 * Robin (Male only)
 * Lucina
 * Roy
 * Corrin (Male and Female)

Fire Emblem Series

 * Alm
 * Celica
 * Chrom - (JP only, WW release on October 20th, 2017)
 * Young Tiki - (JP only, WW release on October 20th, 2017)

Fire Emblem Fates
Upon scanning a Marth, Ike, Robin, or Lucina amiibo, the scanned character will appear as a NPC wandering the player's My Castle in the south. Like other My Castle features, the visiting amiibo character will activate a short event then disappear. Players will need to complete a map in order to resummon the amiibo character again. All other amiibo aside from the four mentioned have no compatibility with Fates.

The first two scans with an applicable amiibo will gift the player an Accessory only available to that character. The answer the player gives to them will determine which one they give.

After two conversation scans, the third time the amiibo is scanned, the character will request a battle between the player's army and their small squad at the Plains of Hoshido. After defeating the amiibo character's forces, they will join the player's army for free and will be added to the player's Unit Logbook. All amiibo characters do not have any secondary classes, but can use DLC seals. They also do not have Personal Skills. Each character, upon recruitment, will always carry their signature weapon in their inventories. While their signature weapons can be unequipped and can equip other weapons, their signature weapons cannot be removed from their inventories.

Subsequent scans will make them appear in one of the shops. If they appear in any of the Armories, they will sell weakened versions of their signature weapons. If they appear in the Accessory Shop, they will sell their unique Accessories.

Each amiibo provides two exclusive accessories that is unique to them. These accessories cannot be gifted to other players. They also have a variation of their signature weapon that is visually the same, but with greatly reduced stats and bonuses.
 * Marth gives the Dragon Headpiece (Tiki's circlet) and Marth's Tiara. Marth's weapon is Marth's Spatha.
 * Ike gives Ike's Pauldron and Yune's Pauldron (Lehran's Medallion). Ike's weapon is Ike's Backup.
 * Robin gives Robin's Books and a Dragon Feather (Grima's wing feathers). Robin's weapon is Robin's Primer.
 * Lucina gives a Bear Hat and her Butterfly Mask. Lucina's weapon is Lucina's Estoc.

Fire Emblem Echoes: Shadows of Valentia
Echoes introduced the first Fire Emblem specific line of amiibo with Alm and Celica receiving amiibo. Upon acquiring a Mila's Turnwheel, players can scan Alm and Celica to unlock a special dungeon. Alm's unlocks Duma's Ordeals while Celica's unlocks Mila's Ordeals. Both reward the player with special equipment when cleared. Additionally, players can copy the data of their current file's Alm and Celica stats onto the amiibo in order to summon them as illusory allies in battle.

During a battle, players can use Alm or Celica to summon an allied Illusory character using the amiibo art command. Summoning Illusory characters will cost Alm or Celica 10 HP per use. The illusory ally summoned is determened whether or not the amiibo is a Fire Emblem series related amiibo or not. Illusory allies are highlighted by their whiteish blue coloration. However, they cannot be commanded and will disappear at the end of the Ally Phase of battle or if they are defeated.

amiibo can be summoned multiple times during a battle, however the player cannot use the same amiibo twice in the same battle. However, each turn, the player is allowed to use a different amiibo to summon another ally. Additionally, once the two armies are combined, only one amiibo can be used per turn. For example, if Alm uses a Mario amiibo, if Celica attempts to summon an illusory ally using Luigi, the allies summoned by Alm will disappear.

Using any of the Fire Emblem amiibo from the Super Smash Bros. for Nintendo 3DS and Wii U line of amiibos will summon an illusory version of that unit. Like the Fates summoned amiibo units, they come with a fixed inventory, including their signature weapon which cannot be removed from their inventory.

Using any non-Fire Emblem series related amiibo will summon a generic Illusory Unit. These Illusory Units are completely random upon each summoning, and can be a generic human unit or Terrors. Hence, a Mario amiibo might summon Barons the first time he is used, but on the second time, he might summon Bow Knights instead. Anywhere from one to three units may be summoned per use.

Fire Emblem Warriors
Warriors are compatible with all amiibo, both Fire Emblem and non-Fire Emblem related. Scanning any amiibo will grant the player gold or weapons and up to 5 different amiibo can be scanned each day.

Scanning the Young Tiki and Chrom amiibo grant weapons with specific skills on the weapons.

Other Compatible Games
Certain Fire Emblem character amiibo are compatible with the following non-Fire Emblem games with special effects:

Chibi-Robo! Zip Lash
Unlocks in-game figurines of Chibi-Robo imitating the scanned amiibo's pose. This feature is not compatible with Roy, Corrin, Alm, or Celica. Subsequent scans with Marth, Ike, Robin, and Lucina and all scans with Roy, Corrin, Alm, and Celica gives the player 50 or 100 Moolah once a day per character, per scan.

amiibo tap: Nintendo’s Greatest Bits
Unlocks demos of various classic games.

Captain Toad: Treasure Tracker
Gives the player 1-Up Mushrooms

Code Name: S.T.E.A.M.
Makes the scanned character usable once per level, although they cannot be revived at checkpoints. (Marth, Ike, Robin, and Lucina only.)

Hyrule Warriors
Gives the player a weapon with up to three stars, a random material, or a random number of rupees. Up to five can be scanned daily.

Kirby Planet Robobot
Scanning a Marth, Ike, Lucina, or Roy amiibo grants Kirby his Sword ability. Scanning a Robin amiibo grants Kirby his Spark ability. All other Fire Emblem amiibo will unlock a random ability.

The Legend of Zelda: Breath of the Wild
Spawns a random assortment of food based items.

Mario & Sonic at the Rio 2016 Olympic Games (Wii U)
Gives the player Coins or Rings that can be used at the item stand.

Mario Party 10
Allows the player to play Scratch Bonus and win Mario Party points.

Metroid Prime: Federation Force
Unlocks a skull-themed recolor for the player's mech.

Miitopia
Grants tickets to play mini-games in the arcade.

Mini Mario & Friends: amiibo Challenge
Creates a Mini Spec to navigate a level.

Style Savvy: Fashion Forward
Unlocks a special skirt design based on Lucina's outfit. (Lucina Only)

One Piece: Super Grand Battle! X
Unlocks a Marth costume for Brook. (Marth Only)

Pokkén Tournament
Gives gold or unlocks a special Trainer Customization or Title. Up to five can be scanned daily.

Super Mario Maker
Unlocks the ability to use the scanned character as a Mystery Mushroom costume for Mario. (Marth, Ike, Robin, and Lucina only.)

Super Smash Bros. for Nintendo 3DS and Wii U
Allows the player to train a computer controlled allied character of the scanned amiibo. (Roy and Corrin can be scanned even without buying the DLC). Only compatible with amiibo from the Super Smash Bros. line.

Yoshi’s Woolly World
Unlocks a yarn print based on Marth, Ike, Robin, or Lucina, depending on the amiibo scanned. All other Fire Emblem amiibo unlocks a generic amiibo design.

Poochy & Yoshi's Woolly World
Unlocks a yarn print based on the scanned character. Corrin and Roy now produce Yoshis based on the two rather than generic Yoshis.

Trivia

 * The first physical non-E-Book item ever sold through Amazon.com Mexico was an Ike amiibo.