In Super Smash Bros.
As a boss opponent
Metal Mario appears in the single player mode of this game as more or less a boss opponent to be battled one-on-one. In this battle that takes place in Metal Mario's Stage, he is a very different fighter than the normal Mario; he barely flinches to ordinary attacks (even throws barely move him at low percents), and takes an absurd amount of damage to KO (often over 300%, and for Star/Screen KOs, 380); only when his damage exceeds 180% can he be knocked down.
On lower difficulties he mainly walks around the stage, seldom attacking, but he can be hard to beat on higher difficulties. When being controlled using codes such as debug menu, Metal Mario is ironically considered by many people as being worse than normal Mario due to his worse Down Aerial, worse Up Aerial, an incredibly bad short hop, is able to be chaingrabbed, usually via repeated Back Throws, and has the same knockback as the other characters. There would also be various rumors of being able to unlock him as a playable character as well as his stage, all of which turned out to be false; just like the Master Hand rumors though he would later become playable along with his stage in hacked versions of the game.
In Super Smash Bros. Melee
As a boss opponent
Metal Mario more or less reprises his role as a special opponent in a single player mode, in this case as an opponent in the level of the Adventure mode taking place on the Battlefield stage, following the battle with fifteen Fighting Wire Frames. Unlike the last time, Metal Mario is not a unique opponent; he is actually a Mario that is permanently under the effect of the newly introduced Metal Box item, except he falls much faster. This makes him more aggressive, and his recovery is longer, but the metal does not increase his weight as much as it used to. If the player has unlocked Luigi, Metal Mario teams up with Metal Luigi for that same battle, making it more difficult. Beating both characters will award the player with the Metal Bros. KO.
Mario can also become Metal Mario by using a Metal Box. However it still produces a weaker effect.
As a trophy
Metal Mario also appears as a trophy which can be acquired randomly through the 1-P mode or the Trophy lottery.
- Metal Mario
- Mario was in for a surprise the first time he hit a Metal Box in Super Mario 64. The metal cap that popped out transformed Mario into living metal, giving him great stamina, a heavy tread, and the ability to walk underwater. In Super Smash Bros., Metal Mario showed up as an incredibly stubborn midlevel boss.
- Super Mario 64 9/96
In Super Smash Bros. Brawl
Despite his role as a boss in Super Smash Bros. and Melee, he, alongside Race to the Finish, didn't return in Brawl. However, Mario can also become Metal Mario by using a Metal Box or battling in Metal Brawl.
In Super Smash Bros. for Nintendo 3DS & Wii U
Once again, Metal Mario doesn't return in the sequel of Brawl, Super Smash Bros. for Nintendo 3DS and Wii U, and Mario can become Metal Mario once again by using a Metal Box or battling in Metal Smash.
- If one looks closely at the reflection on Metal Mario's trophy in Melee, the stage of Yoshi's Island can be seen. This is easiest to spot on his hat, nose or bottom.
- Metal versions of both Mario & Dr. Mario appear in the Mario universe as Metal Mario has appeared in spin-offs (Mario Kart 7, Mario Kart 8, Mario Tennis Open, etc.) while Metal Dr. Mario's only known appearance outside of Smash Bros. is in Dr. Mario 64