Gold is a transformation that appears in Super Smash Bros. for Nintendo 3DS and Super Smash Bros. Ultimate. Fighters affected by this transformation are referred to as gold fighters. It originates from the Mario universe.
Gold fighters deal more knockback to opponents from direct attacks and throws, but projectiles are unaffected. In Smash 3DS only, the fighter will not flinch or receive knockback. When granted by collecting 100 coins on Golden Plains, or by summoning Xerneas, the effect is accompanied by a damage output multiplier, indicated by a red particle effect around the affected fighter. In Smash 3DS, the damage output multiplier is 1.45x (1.3x for specials). In Ultimate the damage output multiplier granted by Xerneas is 1.66× (1.75× for specials) and Golden Plains grants 1.5× (~1.575× for specials). The aesthetic effects of the transformation, such as the metallic appearance and muted voice clips, are similar to that of a Metal Box.
The Metal Killer spirit skill deals increased damage to gold fighters, treating them just like metal fighters. Conversely, Metal Slash does not treat gold fighters as metal fighters, dealing 1% damage instead of an Instant KO.
In Spirit Battles
The effect originates from the Gold Flower power-up, introduced in New Super Mario Bros. 2, which allows Mario to transform into Gold Mario. Gold Mario is a variant of the Fire Mario transformation that allows Mario to shoot golden fireballs which turn breakable blocks and enemies into coins.