Amiibo can only store one game’s data
Nintendo has confirmed that its forthcoming range of NFC Wii U figures has one big limitation - figures can only store data from one game. If you want to use the Amiibo on another compatible game that will write data to it, you’ll have to delete the data already on the figure via the settings on the Wii U.
However, if you wish to use the figure on another title which only uses read-only data, then you won’t have to delete your data. For example, a Captain Falcon figure with Super Smash Bros data on it can still be used for Mario Kart 8 to unlock the extra costume without jeopardising your Super Smash Bros data. Because Mario Kart 8 only needs to read the data on the figure rather than add to it, nothing has to be lost.
Nintendo recently released an update for the Wii U to add Amiibo functionality, including being able to register an Amiibo owner, nickname, and the ability to delete data written to an Amiibo or reset an Amiibo entirely.
Amiibos are launching in the UK on November 28, 2014 alongside Super Smash Bros for Wii U. Nintendo has also partnered with Loot Crate to bring fans special Amiibo crates over the holiday season.