It seems the Mario & Luigi role-playing series has a bit of a jam - a paper jam. Mario & Luigi: Paper Jam was announced during Nintendo's E3 2015 Direct, and it's mashing up the worlds of both Mario & Luigi and Paper Mario. The 2D paper-version of Mario was seen partying up with 3D Mario and Luigi, thus proving the best teammate you can by your side is yourself. As for how the game will play, that remains to be seen, but we did spy a rampaging papercraft Mario at one point flattening enemies into a sheet.
Mario & Luigi: Paper Jam is slated for Spring 2016, and if you want to get all the latest updates on this another other Nintendo games shown during the Direct, but sure to stay tuned to GamesRadar+ and our E3 2015 hub page.