Using Amiibo in 'Super Smash Bros. Ultimate' unlocks fighters, spirits, and training partners. Enable NFC on your Switch: go to 'System Settings' > 'Controllers and Sensors' > 'NFC' and toggle it on. Launch the game and go to the 'Games & More' menu. Select 'Amiibo' to access the Amiibo menu. Hold the Amiibo figurine to the NFC reader (right Joy-Con’s top, Pro Controller’s center, or adapter for Switch Lite) for 1-2 seconds. Amiibo of Smash fighters (e.g., Mario, Link) unlock the character if you don’t already have them, or grant a custom spirit. You can train Amiibo fighters to battle—feed them spirits to boost stats and teach moves, then use them in battles against friends or CPU opponents. Amiibo also grant in-game items like gold, snacks, and custom outfits for Mii Fighters. Collect different Amiibo to unlock unique content and build a powerful Amiibo army.