All-Star Battle: Secret is a single-player event match in Super Smash Bros. for Wii U. In it, the player must choose a character and take on the fighters who were unlockable in previous Smash Bros. games. The first are the first four unlockable characters who have been in every Smash Bros. game, though arranged according to Brawl, Ness, Luigi, Captain Falcon, and Jigglypuff, followed by Dr. Mario, being unlockable in Melee, and the last being Toon Link, R.O.B., and Sonic, who were unlockable in Brawl.
- The music used in this event, Credits (Smash Bros.): Ver. 2, normally plays on Battlefield, rather than Onett.
- Ironically, R.O.B. and Dr. Mario are the only characters faced to be unlockable in Super Smash Bros. for Wii U.