Mario & Luigi: Paper Jam Bros out on December 4

Surely two Marios are better than one. That's something you'll be able to explore in Mario & Luigi: Paper Jam Bros. that will see release on December 4. This will be the fifth time that we get acquainted with Mario in paper form and the first time Paper Mario and Mario & Luigi are mashed up in one game.

Here's an excerpt on the story from the press release:

"Everything begins when Luigi accidentally finds and opens a mysterious book that somehow draws the characters from Paper Mario in Mario & Luigi's world. Now it's up to you as a player to take control of the trio consisting of Mario, Luigi and Paper Mario. Defeating Bowser and Bowser Paper so that all of the Paper Mario universe can come back to his world again."