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The Blue Pipe is a pipe item found in Mario Pinball Land. These items can help Mario from losing a life or from leaving the area Mario is supposed to be. They usually appear when the player ventures into a new area as they appear between the flippers the player controls. It can be obtained by buying it from Toad, or hitting a ? Block.
They return in Paper Mario: The Thousand-Year Door where they appear in the middle of Rogueport Sewers sublevel 2 to serve as shortcuts to Petalburg, Boggly Woods, Keelhaul Key, and Poshley Heights. The first two require the Super Hammer, and the last two requires the Ultra Hammer. There is also a differently colored blue pipe that leads to Fahr Outpost. They also appear in Super Paper Mario, where they are built by Welderberg. There are three in the game: One leads to Flipside's B2F, one to Flopside's B2F, and one to Flopside from Flipside (and vice versa). Each is accessible on the second floor of both cities.