You need a GameCube Controller Adapter. The Wii (RVL-001) has four GameCube controller ports hidden under a flip-down cover on top. The Wii Family Edition (RVL-101) and Wii Mini remove these ports—adapter required for those models.
| Adapter | Ports | Compatibility | Price |
|---|---|---|---|
| Official Wii U GCN Adapter | 4 | Wii U (Wii Mode, Smash 4), Switch, PC | $25–40 used |
| Mayflash 4-Port (MAGIC-NS / F300) | 4 | Wii U, Switch, PC, PS3, Android | $20–30 |
| Raphael's GCN to USB (DIY) | 1 | PC, MiSTer, custom | $15 parts |
Original Wii: plug in directly. Family Edition/Mini/Wii U: Mayflash adapter + homebrew (Nintendont) for full support.