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, usually due to said rights either expiring or never existing, but it can also be due to the creator forfeiting said rights. Examples of such works include the English language, the formulae of Newtonian physics, 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. 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 1923 in the United States)
- 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 1923 and 1963, but the copyright owner failed to renew their copyright. (After 1963, renewal became optional.)
- In the United States at least, if the work was originally created by the US Government, it is automatically in the Public Domain at creation. (This is why the Private Snafu cartoons and the "Why We Fight" films of Frank Capra are in the public domain).
In the United States, a vast majority of works produced prior to 1923 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.
Here on TV Tropes, the Public Domain comes into play via four different tropes:
Pages Covering Public Domain Works:
- Public Domain Animation: Cartoon short subjects that exist in the public domain.
- Public Domain Comic Books: Comics, usually from the Golden Age to the early Silver Age, that are no longer under copyright.
- Public Domain Feature Films: This covers public domain feature length movies such as The Birth of a Nation (1915) and Night of the Living Dead (1968).
- Public Domain Stories: This includes folklore, short stories, poems and novels that exist in the public domain.