can you get dmca'd if you simply don't call it zelda even though it's obvious that it is?
There are three main types of intellectual property, and a few minor ones (though we did see them discussed with a PS5 skins thread the other day).
The big three are
Patents. Don't apply to software unless you are in the US or Japan, though the US would sorely love them to apply elsewhere. Elsewhere mostly says software is maths and you can't patent maths you utter cretin. Still there have been cases of software patents bothering games -- it is generally held that the smooth transition between cameras in racing games being a Sega only thing was as a result of a patent. Equally what goes in the US does trickle out if we are doing the whole international business thing and I don't think I have ever seen a patent induced censorship dodge in games where the US lacks something Europe might have/allow.
Trademark.
These are usually for things like logos, catchphrases, brand names and the like. Things designed to prevent confusion with customers as to what is your product/the real deal
http://tmsearch.uspto.gov/bin/showfield?f=doc&state=4809:una1xe.2.2 is one for pikachu (a pokemon for the unaware), though there are further ones for detective pikachu exist.
http://tmsearch.uspto.gov/bin/showf...h&a_search=Submit+Query&a_search=Submit+Query
If you want Nintendo of America in general
http://tmsearch.uspto.gov/bin/showf...h&a_search=Submit+Query&a_search=Submit+Query
Here is one featuring a Zelda character (in this case a description and example picture of Link, though it is fairly specific.
http://tmsearch.uspto.gov/bin/showfield?f=doc&state=4809:una1xe.4.46
Trademark is usually what hits fan games and while the C in DMCA stands for copyright if you are using it in a more colloquial verb form ("takedown notice" and "cease and desist" tending to be more useful terms) then yeah that would count. It is also fairly evidently a big aspect of things like the footage usage rules that various companies put out
https://www.xbox.com/en-us/developers/rules (the parts about names, not using hacked or glitched content and so forth).
Copyright. This gets very very very confusing very fast. As a general concept this covers the expression of a work. Script, music, artwork (
https://www.forbes.com/sites/emmawo...nfringing-cat-meme-copyright/?sh=237339f42e34 ), code itself and the list of exemptions/exceptions/allowable uses is tricky (fair use is what most would start with here, critique/review/parody/eduction/... you might have met before, however we are probably supposed to note it is a defence, not a right per se)
https://fairuse.stanford.edu/overview/fair-use/four-factors/
We have seen even big companies go after each other for copyright infringement when making similar games, though it is rare indeed, usually discouraged by copyright lawyers, and usually quite notable when it happens, and most cases (though not all) are usually more company A keeps source code they made on contract with big publisher B to use with their new game, disagreements over engines, or similar.
Copyrighting a gameplay style is not really the done thing -- a method of doing something is usually what patents cover, though the expression of a gameplay style is copyrightable to some extent (this was part of that Rainbow Six Siege vs Area F2 thing not to long ago, though
https://www.wired.co.uk/article/ea-vs-zynga back in 2012, now I wonder who had thought of Zynga in recent years, is probably the main example of such things). Most times a word like clone gets thrown around then there is next to nothing the company being "cloned" can do, and frankly that is one of the few rays of sunshine in US copyright law.
For a fan game I would usually expect it when they borrowed some artwork/music, "remix" or "inspired by" is a hard stretch as much as "changed two notes"* or "changed a couple of pixels" (see "derived works", though shockingly to me is disassemblies and decompiled versions of games are available in all their glory on public source code repositories located in the US and have been for years and years now in some cases).
*how many notes is a fairly common debate among music lawyers. It is usually more of a subjective thing but there have been some very low counts, and the law itself gets rather hazy.
So yeah you are free to release high fantasy small boy is the chosen one that battles through puzzle dungeons ending with bosses all day long. Don't borrow artwork and also try to avoid some manner of "tracing" (though comics do such things all the time, even if it is frowned upon) and that makes life rather easier. How many elements you would need before either a viable case (bombs, hearts and arrows is nothing major, bomchus, hookshoot, master sword... trickier) much less one Nintendo would be inclined to take on (which is also a function of how much of a thorn in your side you are**), varies and gets very fuzzy.
**trademarks have a duty of protection. If you allow too many people to use your trademarks it risks becoming "genericised". This is also why many are viewed as aggressive towards fan games, especially after "big" trade magazines pick them up.
https://www.eff.org/deeplinks/2013/...-require-companies-tirelessly-censor-internet for a slightly different take.
http://self.gutenberg.org/articles/eng/list_of_generic_and_genericized_trademarks https://digitalsynopsis.com/advertising/generic-trademark-product-brand-names/ for lists of things troubled here.