Public Domain Characters in Games: Copyright vs. Trademark

Public domain characters are some of the most useful building blocks in game design. Cthulhu, Sherlock Holmes, Dracula, Alice, Robin Hood, and King Arthur show up in board games and video games constantly, because nobody owns the stories anymore.

But “public domain” only answers a copyright question. Trademark law runs on a different clock, and it can still catch you even when the character is free.

This guide covers how to tell whether a character is really in the public domain, which version of it you can use, and where trademark law creates problems. It ends with a short list of public domain characters popular in games and what to watch for with each.

When do characters become public domain?

A character becomes public domain when the copyright on the work that first published it expires. There’s no separate copyright clock for the character itself.

For works published before 1978, US copyright lasts at most 95 years from publication. Under 17 U.S.C. § 305, every term runs to the end of the calendar year it would otherwise expire.

So the math is simple: add 95 to the publication year, and the work is free on January 1 of the following year. As of 2026, anything published in the US in 1930 or earlier is out of copyright.

That’s why A.A. Milne’s first Winnie-the-Pooh book (1926) went public domain in 2022. Steamboat Willie, the 1928 Mickey Mouse cartoon, followed in 2024.

Three wrinkles trip people up:

• “Published” is the trigger, not “written.” According to the Duke Center for the Study of the Public Domain, the script of Barrie’s play Peter Pan wasn’t “published” for copyright purposes until 1928. The play only entered the US public domain in 2024.
• Some works fell out early. Older works needed a copyright renewal to get their full term, and many never got one. Duke reports that the February 1928 issue of Weird Tales, which carried Lovecraft’s “The Call of Cthulhu,” appears never to have been renewed and went public domain in 1956.
• Newer works run much longer. Under 17 U.S.C. § 302, works created from 1978 on last for the author’s life plus 70 years. A work made for hire, which covers most studio-made characters, gets 95 years from publication, so no modern video game character is anywhere close.

For a broader walkthrough of checking copyright status, see how to know if something is in the public domain. For games themselves rather than characters, see board games without copyright and how long video game copyrights last.

Only the public domain version is free

This is where most people get burned. When a character’s first appearance goes public domain, you get that version, not every version that came after it.

The leading case is Klinger v. Conan Doyle Estate, 755 F.3d 496 (7th Cir. 2014). Arthur Conan Doyle published 56 Sherlock Holmes stories and 4 novels between 1887 and 1927, and in 2014 the last 10 stories were still under US copyright.

The Doyle estate argued that because Holmes and Watson kept developing in those late stories, the characters as a whole stayed protected. It had been demanding license fees from publishers of new Holmes stories on that theory.

The Seventh Circuit rejected the argument. It held that the late stories were derivative of the early ones, so “only original elements added in the later stories remain protected.”

As the court put it, “The alterations do not revive the expired copyrights on the original characters.”

The court gave concrete examples. Only the late stories reveal that Holmes came to like dogs and that Watson married twice, so those details stayed off-limits until the late stories expired too.

For game makers, the lesson carries straight over. The 1926 Pooh is free.

Disney’s versions came after it acquired Pooh rights in 1961 (Milne v. Stephen Slesinger, Inc., 430 F.3d 1036, 1040 (9th Cir. 2005)), and anything original Disney added is still its property.

The same goes for the 1928 Mickey. Duke’s summary is blunt: only the original 1928 works entered the public domain, and later versions may still be copyrighted.

Work from the original source. Pull your character description from the public domain book, film, or illustrations, and design your own look from there.

What trademark law can’t do: Dastar

Once the copyright is gone, can a company use trademark law to stop you from copying the work? The Supreme Court said no in Dastar Corp. v. Twentieth Century Fox Film Corp., 539 U.S. 23 (2003).

Fox let the copyright lapse on a TV series about World War II. Dastar copied and re-edited the footage and sold it under its own name, and Fox sued under the federal trademark statute.

The Court refused to let trademark law fill the gap.

Allowing the claim, it said, would “create a species of mutant copyright law that limits the public’s ‘federal right to “copy and to use”’ expired copyrights.” Id. at 34.

So you can retell the public domain story, use the public domain character, and adapt the public domain art. Nobody can use a trademark claim to take that back.

What trademark law can still do: Frederick Warne

Dastar protects your right to copy the work. It doesn’t let you borrow someone else’s brand.

The classic example involves Peter Rabbit. In Frederick Warne & Co. v. Book Sales Inc., 481 F. Supp. 1191 (S.D.N.Y. 1979), Beatrix Potter’s original publisher conceded that seven of her books were in the public domain.

But Warne had registered three of its cover illustrations as trademarks for books, including the “running rabbit.” A competitor published the seven stories in one volume and used reproductions of those covers as ornaments on nearly every page.

The court refused to throw out Warne’s trademark claim.

It explained that “the fact that a copyrightable character or design has fallen into the public domain should not preclude protection under the trademark laws so long as it is shown to have acquired independent trademark significance.” Id. at 1196.

In plain English: if a company has used a character’s image as its brand long enough that buyers see it as a signal of who made the product, that brand use can be protected. The character itself stays free.

After Warne sued, the competitor swapped its “sitting rabbit” cover for a rabbit design of its own. That’s the safe move from the start.

The LITTLE MERMAID and RAPUNZEL filings

Trademark law cuts the other way too. A classic character’s name is often too descriptive to own at all.

In In re United Trademark Holdings, Inc., 122 USPQ2d 1796 (TTAB 2017), the Trademark Trial and Appeal Board refused to register LITTLE MERMAID for a mermaid doll. It found that buyers would read the name as describing Hans Christian Andersen’s public domain character, not as a brand.

The Board contrasted that with a character like Superman. Buyers expect Superman products to come from, or be licensed by, the company that created and owns the character.

The same applicant then filed to register RAPUNZEL for dolls and toy figures. This time the application passed examination and was published for opposition.

A doll collector and mother opposed it on the ground that RAPUNZEL is generic for a Rapunzel doll. She brought a petition with 432 signatures.

She never got to argue the point.

In Curtin v. United Trademark Holdings, Inc., 137 F.4th 1359 (Fed. Cir. 2025), the court held that a consumer’s interests don’t give her the right to bring an opposition. To oppose, you need a commercial stake, which usually means you’re a competitor.

The genericness question was never decided. For anyone making toys, games, or merch around classic characters, that means the job of fighting a bad registration falls on you.

How to fight a bad registration: letters of protest and oppositions

You have two tools, and timing decides which one you get.

A letter of protest is open to any third party under 37 C.F.R. § 2.149, with no commercial stake required.

It hands the examining attorney evidence supporting a refusal, like dictionary entries or proof that everyone uses the term to name the product.

The rule caps you at 10 items of evidence per refusal ground and 75 pages total unless you can show special circumstances, and it bars legal argument. If you file before the mark is published, the evidence only has to be relevant to the ground for refusal.

If you file within the 30 days after publication, it has to make a prima facie case for refusal, which is a much higher bar. After that window, the letter of protest route is closed.

The USPTO charges a fee for each letter of protest.

Two limits matter. Your involvement ends when you file, and the USPTO’s decision on whether to use your evidence is final.

Filing also doesn’t pause anyone’s deadline to oppose.

Here’s our guide on writing a letter of protest an examiner will actually use.

An opposition is a full proceeding before the Board.

Under 15 U.S.C. § 1063(a), it has to be filed within 30 days after publication, and you can get an automatic 30-day extension if you ask before the first window closes.

After Curtin, you need a real commercial interest to bring one. If you sell competing products, you have it.

More on the process in our guide to the notice of opposition.

Public domain characters list: what to watch for in games

Here’s a short list of public domain characters that show up in games often. The “watch out” notes flag specific, documented issues.

Where nothing is listed, the general rules above still apply.

Sherlock Holmes

Is Sherlock Holmes public domain? Yes, all of him now.

Klinger notes the last story was published in 1927, so under the 95-year rule the final copyrights ran out at the end of 2022.

Watch out for: later adaptations. Film and TV versions of Holmes carry their own copyrights in whatever they added.

Winnie-the-Pooh and Tigger

The first Pooh book (1926) is free, and Duke lists The House at Pooh Corner, which introduced Tigger, among the 1928 works that entered the public domain in 2024.

Watch out for: Disney’s versions. Disney acquired Pooh rights under a 1961 agreement, and its own additions to the characters are not free.

Mickey Mouse (Steamboat Willie)

The 1928 Mickey from Steamboat Willie is public domain. Disney still holds trademark registrations for Mickey Mouse, so its brand rights continue.

Watch out for: anything that suggests Disney made or approved your product. Use the 1928 design only, and keep it off your logo and box art.

Cthulhu

Lovecraft’s “The Call of Cthulhu” first ran in the February 1928 issue of Weird Tales. On Duke’s account it went public domain decades ago, and on any count it is free now.

Watch out for: the game name. Chaosium holds a live US registration for CALL OF CTHULHU (Reg. No. 1,621,407), a stylized mark with an illustration, for rulebooks and supplements for a fantasy roleplaying game.

Dracula

Bram Stoker’s novel dates to 1897, so the Count himself is free.

Watch out for: the Universal film look. Universal released its Dracula in 1931, so under the 95-year rule any copyright in that film can last no longer than the end of 2026.

Alice

Lewis Carroll published Alice’s Adventures in Wonderland in 1865. Alice, the White Rabbit, and the Cheshire Cat are all free.

Watch out for: Disney’s 1951 animated film. Its designs can stay under copyright through the end of 2046.

Peter Pan

Duke reports that Barrie’s 1911 novel Peter and Wendy has been public domain in the US since 1967, and the play since 2024.

Watch out for: the UK. Schedule 6 of the UK Copyright, Designs and Patents Act 1988 gives Great Ormond Street Hospital’s children’s charity a royalty on public performance, commercial publication, or communication to the public of the play or an adaptation of it.

Check it before a UK release.

Tarzan

Edgar Rice Burroughs’s Tarzan of the Apes first appeared in The All-Story magazine in 1912, so the original story is free.

Watch out for: the yell. Edgar Rice Burroughs, Inc. holds a live sound mark registration for the Tarzan yell (Reg. No. 2,210,506) for toy action figures.

Zorro

Zorro comes from Johnston McCulley’s story “The Curse of Capistrano.” In Sony Pictures Entertainment, Inc. v. Fireworks Entertainment Group, Inc., 156 F. Supp. 2d 1148, 1156 (C.D. Cal. 2001), the court wrote: “It is undisputed that Zorro appears in works whose copyrights have already expired.”

Watch out for: Zorro Productions, Inc.

In Cabell v. Zorro Productions, Inc., 155 F. Supp. 3d 1143 (W.D. Wash. 2014), the court noted the company claims to be the worldwide proprietor of the ZORRO trademark.

The author of a Zorro musical alleged the company threatened his licensees with legal action. That court dismissed the case for lack of jurisdiction without deciding who was right.

Robin Hood and King Arthur

These come from centuries-old folklore, and no copyright ever covered the core legends. The risk sits in modern retellings, which carry their own copyrights in their own additions.

What you should do

• Confirm the date. Find the first publication date of the work the character comes from. If it’s 1930 or earlier, the US copyright is gone.
• Use the public domain version, not the famous one. Build from the original text and art. Leave out later costume changes, personality traits, and design choices a studio added.
• Design your own look. Don’t copy the title treatment, logo, or packaging of the best-known version. That’s where the trademark and trade dress claims come from.
• Search the USPTO register before you name the game. Classic names get registered for games, toys, and apparel. Check your product category, not just the name.
• Add your own brand. “Dracula” alone is weak and probably not yours to own. “Dracula” plus a distinctive title from your studio is something you can protect as a trademark.
• Check your release territories. US public domain status doesn’t carry over to every country, as Peter Pan in the UK shows.
• Watch for filings in your space. If someone applies to register a public domain character’s name for games, file a letter of protest while it’s still in examination. If you sell competing products, you can also oppose within 30 days of publication.