Which company developed the Paper Mario series?

Intelligent Systems developed the Paper Mario series. Nintendo publishes the games, but Intelligent Systems is the development company most closely associated with creating the series and its distinctive paper-based role-playing adventures.

The original Paper Mario was developed for Nintendo 64 and released in Japan in 2000. It was initially conceived as Super Mario RPG 2, following the Super Nintendo game developed by Square. When Square could not take on the project because of its work on Final Fantasy VII, Nintendo assigned development to Intelligent Systems.

Intelligent Systems helped establish the series' signature combination of turn-based battles, partners, puzzles, action commands, and paper-themed visual design. The studio also developed later entries such as Paper Mario: The Thousand-Year Door and Paper Mario: The Origami King.

Nintendo is a common wrong answer because it owns and publishes the franchise. Square Enix is linked to Super Mario RPG's original developer, Square, while Rare developed other Nintendo-associated games but not Paper Mario.