There are two primary definitions for the term public domain. The one we won't be discussing is public land that can be purchased from the government for a small amount of money and if you homestead it for a few years, it becomes yours.
The term "public domain" that we will discuss here refers to the collective of works not covered by intellectual property rights in any way whatsoever. This is usually due to said rights either expiring or never existing, but it can also be due to the creator intentionally forfeiting said rights. Examples of such works include the English language, the formulae of Newtonian physics, recipes, the works of Shakespeare and Beethoven, and the patents on powered flight. This also applies to many old movies, cartoons, novels, poems, comics, and various other works of entertainment, science, and general knowledge. In general, Public Domain works make for a great resource for those who would like to use properties in their work, but don't have a lot of cash.
Since Public Domain works don't have the protection of copyright or other IP rights, anyone can use them as the basis for new creative works without fear of running into lawsuits or other legal issues. In essence, someone is free to use, adapt, change, or implement entire sections of the work as they so choose (including the entirety of the work), even for profit, all without asking permission or paying royalties. Shakespeare's works, for example, have received numerous film adaptations with their own unique spin on The Bard's tales. People can also use those works, in part or in whole, within a new creative work (someone can quote as much Shakespeare as they want within a film).
In general, works enter the public domain by one of several means:
- The work existed before copyright laws existed (generally anything before the 1800s)
- The work got published after the creation of copyright, but it existed long enough for its original copyright to have expired (anything published before 1925 in the United States, except for sound recordingswith changes to US copyright law made in 2018, pre-1924 recordings enter the PD in 2022).
- The work's copyright lapsed due to age (with the current legal standard for the US holding that age at seventy years after the death of the creator, or 120 years after creation/95 years after publication [whichever is less] for works where a corporate entity is the creator).
- The copyright holder waives their copyright, or the owners aren't around to renew it and no one else has claimed ownership of the property—for example, this is what allowed the entire Van Beuren cartoon studio library to become public domain, since the independent studio abruptly went belly up in 1936, its founder died soon after, and their generally unpopular films faded into obscurity after the fact, save as quick to make home movie rentals decades later.
- The work got published at any time between 1925 and 1963, but the copyright owner failed to renew their copyright. (After 1963, renewal became optional.)
- The work was published between 1925 and March 1, 1989 with a faulty copyright notice. (e.g. missing a copyright symbol [or the word itself], year or claimant)
- In the United States at least, if the work was originally created by the federal government, it is automatically in the Public Domain at creation. (This includes the Private Snafu cartoons and Frank Capra's Why We Fight films.) The word "federal" is important in this contextworks created by state governments may or may not be PD, depending on the laws of the relevant state.
- That said, other federal laws can take certain government-created properties out of the PD. One notable example is Smokey Bear, the mascot of the US Forest Service. Created in 1944 under the direction of the Forest Service, he's been under the control of that agency's parent, the US Department of Agriculture, since 1952, when Congress passed and President Truman signed a bill to that effect.
- It was created by a machine or non-human animal. (Stern Electronics Inc vs. Kaufman ruled that video game images may be copyrighted.)
In the United States, a vast majority of works produced prior to 1925 have fallen into the public domain (with a few exceptions existing thanks to legal issues); works produced thereafter may or may not fall under copyright, owing to a litany of circumstances (including various extensions of copyright terms).
For certain works, international laws and treaties complicate matters further. While the King James Bible falls under the public domain in the US, over in the UK, the Crown holds it under perpetual copyright.
Public Domain Tropes:
- Public Domain Artifact: Various objects that originate from old folklore and ancient legends.
- The Public Domain Channel: An in-universe Show Within a Show that is actually public-domain media in the real world.
- Public Domain Character: Fictional characters that are owned by nobody, thus allowing anybody to use them.
- Public Domain Soundtrack: Music that is completely free of any royalties, and thus can be inserted into any media.
Public Domain Works:
- Public Domain Animation: Animated short films that exist in the public domain.
- Public Domain Comic Books: Comics, usually from the Golden Age to the Silver Age, that are no longer under copyright.
- Public Domain Feature Films: This covers public-domain movies such as The Birth of a Nation (1915) and Night of the Living Dead (1968).
- Public Domain Stories: Various folktales and works of written literature that exist in the public domain.