Split play time between Bowser. View larger.

And the team of Mario & Luigi. View larger.

Two stories and gameplay paths that can affect each other in real-time. View larger.

Story
The story of Mario & Luigi: Bowser's Inside Story is an atypical one in the world of Mario and Luigi in that the two plumbers team up with Bowser for the good of the Mushroom Kingdom, even if Bowser is totally unaware of it. As the game opens the Mushroom Kingdom is seen to have been struck by a sort of infection known as "The Blorbs," and exposure to it has caused out of control physical ballooning of the Toads. A council of the who's who in the Kingdom, including Mario and Peach, is assembled to try and figure out what to do about it, when right on queue, in barges Bowser, intent on dragging away Peach. He is stopped and shown the door by Mario, but later is tricked by the villain Fawful to eat a "Lucky Mushroom." Brainwashed by this, he returns to the council where the mushroom causes all the council to shrink to a tiny size and Bowser to literally inhale them. Fawful and his henchmen then set about taking over all of the Mushroom Kingdom, even the parts that Bowser has staked a claim to. Nobody, except maybe Mario, takes what is Bowser's, so there is going to be trouble. Although now very small, Mario realizes a few things. Peach, as usual, has gone missing, Bowser and he are on the same side in this fight and that Bowser will need help. How will Mario save the day this time? That's up to you.

Gameplay
A single player action RPG, action in Mario & Luigi: Bowser's Inside Story is split between the player-controlled team of Mario and Luigi, trapped in Bowser's stomach, and Bowser himself. These play out as two separate paths of action, constantly overlapping, which players can toggle between and engage in. As they do so players see that Bowser's actions on the outside affect the conditions for Mario and Luigi in his stomach, and the actions of the plumbers can add or subtract from Bowser's abilities. Examples of this are the good and bad things that Bowser swallows that the Bros. must deal with, and conversely the toll an illness the Bros. can affect has on Bowser's physical abilities. Players can see this link for themselves when at times during the game Mario and Luigi are shown on the lower DS screen, while simultaneously Bowser moves in in-game real-time on the top screen. Again, these two paths lead to the same place, the defeat of Fawful. The challenges that players face in doing this is the basis for the RPG gameplay, with players gaining experience points in the challenges that they face, which can be used to level up character-specific fighting and other abilities and even buy in-game gear. Additional gameplay includes puzzle-solving, searching for hidden items, mini-games and more, engaged in as the team of Mario and Luigi, and Bowser on his own.

Key Game Features

• Two Separate Storylines - One features Bowser and his efforts to stop an arch-villain from taking over his castle. Meanwhile, inside Bowser, the microbe-sized Mario and Luigi must muscle their way through challenges and keep their nerve if they want to find a way out. They take action to control Bowser from the inside – but without his knowledge.
• Switch Between Storylines at Will - What happens inside Bowser affects what he’s doing on the outside. Sometimes Mario and Luigi must solve puzzles and challenges behind the scenes to help Bowser overcome various obstacles and advance the plot.
• DS/DSi Integrated Gameplay - In some battles, Bowser grows so large that players must turn their Nintendo DS or Nintendo DSi system sideways, blow into the microphone or tap on the touch screen with the stylus to keep up with the action.
• Distinctive Nintendo Humor - The game features the same hilarious dialogue that has been the hallmark of the Mario & Luigi series.
• RPG Gameplay - A players work their way through challenges they can level characters up with experience points.