Will Nintendo sue?

If anybody is interested in what this is all about, it's an OS project called Full-Screen Mario, a clone of the original SMB using HTML5. I had a little play, and so far it seems like a pretty good clone: http://www.fullscreenmario.com/

Might be worth contributing to if you are interested in HTML5 game dev or have some experience with the potential legal issues surrounding the project.

The developer uses Nintendo's trademark "Mario" in the title of his video game project. (Edit: As pointed out in the comment below, the name "Mario" itself is not trademarked, so to be correct the previous sentence should instead read "The developer uses Nintendo's trademark Mario in his video game project.") I'm not a lawyer but as far as I understand (unlike with copyright) Nintendo is legally obliged to react and protect it, right?

Edit: Concern about trademark issues is also what apparently led to the Super Mario Clone FOSS project (http://sourceforge.net/projects/smclone/, note the URL) being renamed Secret Maryo Chronicles. I'm not sure if Nintendo ever contacted them or if it was a precautionary change.

Edit 2: There's some interesting commentary from a professional lawyer on the issue of trademarking and copyrighting characters at http://www.ivanhoffman.com/characters.html, though it's from 2003.

If they notice, they'll probably complain. Nintendo is fairly hardline on this kind of thing, afaict.

An academic conference in my area used to host an annual "Mario AI championship", where competitors submitted either Mario-playing AI controllers, or systems to procedurally generate Mario-like levels [1]. After a few years someone at Nintendo found out, and demanded that we: 1) stop using the name "Mario", and 2) stop using the Mario assets in the procedural level generation framework. Imo there was a decent fair-use claim in that case, but nobody wanted to pursue it, so now it's informally referred to as the "Non-Mario AI competition" [2]. (As a direct reimplementation of an actual Mario Bros game, the project here seems like it would not really have a good fair-use claim, anyway.)

That's in contrast to Blizzard's reaction to the annual Starcraft AI competition [3]: once they found out about it, they sent a representative and donated prizes.

[1] http://julian.togelius.com/Togelius2013The.pdf

[2] http://platformersai.com/

[3] http://webdocs.cs.ualberta.ca/~cdavid/starcraftaicomp/

They're not obligated to do so, but they do have the right to do so. The name Mario is not a trademark itself since common names cannot be trademarked, although product names containing the name Mario are trademarked by Nintendo, such as Super Mario. I think Nintendo has sufficient grounds to sue because this project uses the name Mario in concert with an actual rework of a Nintendo product which itself is copyright. Most likely they won't resort to a lawsuit right away, instead will send a cease and desist.

Although the SC AI guys are still stuck with BW, not SC2 :'(