Mario World

Mario World, called Mario's world in the English translation of Super Mario RPG: Legend of the Seven Stars, refers to the lands that the Smithy Gang tried to conquer. After Mario had most recently rescued Princess Toadstool from King Bowser, a giant sword known as Exor plunged into Bowser's Keep and sent the three flying in separate directions from the impact. While Mario was on his journey with Mallow to discover the fate of the princess and figure out the connection between the sentient blade's nature and the recently appearing monsters, he finds a mysterious walking doll known as Geno that became aware and grew life-size. Geno reveals that he is actually an emissary of the Star Road, which was shattered by Exor shortly before crashing into Bowser's Keep. The Star Road grants the wishes of the world which take the form of small shooting stars that fall on the mystical Star Hill. Smithy knew this, and from his new base of operations sent his crew to collect the fallen Star Pieces to prevent it from ever being restored and fulfill his own dream of filling the world with weapons. With the willpower of friend and foe alike, Mario's allies united against this common enemy. In the end, the Star Road was restored, Geno's starry essence returned to keep watch over the Star Road, and Exor vanished into the wind never to be seen again.

Trivia

 * The term "Mario World" was first used in the instruction booklet of the console ports of Mario is Missing! However, in that context, it may instead refer to the direct counterpart of "the real world," which was a distinguishing concept utilized in contemporary cartoon and film media.
 * The name is also reused in Mario Tennis: Power Tour, though in that instance it appears to apply to the petite floating area in the clouds which houses the Peach Airport and Peach Dome.