Paper Mario: The Origami King previews are coming in from other sites, like Venture Beat and GameXplain, which means gameplay details are coming in. While some have already been discussed, like it having a more open world that is all connected, things Nintendo hasn’t been hyping up have been discussed too. For example, there are no Paper Mario: The Origami King experience points. That also means no leveling up.
As pointed out in many previews, battles in Paper Mario: The Origami King don’t include that RPG staple, even though the game itself is a part of a series that has traditionally been an RPG. To improve Mario’s stats, people must instead find items that increase his health, Confetti bag upgrades, and folded Toads to increase the number of people in the stands at his fights and provide more assistance opportunities. However, even though there’s no Paper Mario: The Origami King EXP or incentive to repeat battles, enemy respawning does occur.
You can see GameXplain’s explanation at the one minute mark in the video below.