Special Mode is a term in Vs. Mode that's featured in Super Smash Bros. Melee (known as Special Melee), Super Smash Bros. Brawl (known as Special Brawl), Super Smash Bros. for Wii U (known as Special Smash), and Super Smash Bros. Ultimate (known as Custom Smash) which allows players to add in special rules into each match. Although it does not appear in Super Smash Bros. for Nintendo 3DS, many of the Final Battles in Smash Run enable one of the options as seen in Special Smash. One important note is that matches played in this mode do not count for statistics in Records or the completion of some challenges.
Unlike Melee's Special Mode, where only one special condition could be played at any time, Special Brawl allows several options to be applied at the same time. One can even play without any options, and simply play a normal match where records are not recorded.
The mode returns once again in Super Smash Bros. Ultimate under the name Custom Smash. It has the same conditions from Smash 4, except for 300%/Stamina, as Stamina became a standard game mode while 300% (now called Super Sudden Death) became it's own game mode.