This article is about one of Nintendo's divisions. For the room in Luigi's Mansion: Dark Moon, see Tree House. For Donkey Kong's home, see DK's Tree House.
Treehouse is the product development division of Nintendo of America. Though the name is often used to refer solely to the localization department, "Treehouse" englobes the localization team, audiovisual department, product management, and quality assurance work.
Treehouse handles American English, Canadian French, Pan-American Spanish, and Brazilian Portuguese localizations for the Pan-American market. Treehouse started as an initiative to address the lackluster quality of the English localization of Nintendo games during the 8-bit and 16-bit era. The department often translates games as they are being developed and thus often communicates with the Japanese development teams. The Japanese developers also consult Treehouse to prevent the inclusion of culture-specific content that could prove alienating to international audiences.
The "Treehouse" name finds its root in Donkey Kong Country; the team handling the North American localization of the game was "locked away" from the rest of NOA due to Nintendo's high secrecy toward the game and was codenamed "Treehouse" after Donkey Kong's residence. As Treehouse expanded, the name stuck.
From its founding up to the early Wii years, Treehouse's English translations were used for the English script in all English-speaking and English-defaulting regions, with minor editing to account for difference in spellings between American and British English as well as replacing any potentially offensive content (examples of the later include removing an instance of the word "shag" in Super Paper Mario as well as the sentence "I don't get my jollies doing nice things" in WarioWare: Smooth Moves being changed to "I don't get my kicks doing nice things"). After Mario Party 8 was recalled in the United Kingdom due to featuring the word "spastic" (a term considered benign in the United States but considered highly offensive in the United Kingdom), American and British English scripts started to differ more, to varying degrees, ranging from games with largely similar translations but different object and character names to completely different scripts. However, this practice has been abandoned beginning with games released for the Nintendo Switch, going back to extremely similar, if not identical, translations between American and British English localizations.
For a time, Treehouse's scripts were also used as the basis for translation in other languages. One example of this practice is the European French translation of Paper Mario, which features many character names and dialogue clearly based on Treehouse's writing rather than the original Japanese script. This practice largely stopped after the release of the Nintendo GameCube, although Treehouse's own Canadian French and Pan-American Spanish translations often share terminology with the English one.