For most of the world today, if you get caught doing a crime, you do the (sometimes metaphorical) time associated with the crime. The justice system is there to ensure you get a punishment that fits what you've done.
But in fiction where Big Bads can plot to Take Over the World or commit countless atrocities in pursuit of their goal, the heroes might find that there is no adequate punishment for the Big Bad's crimes. If they'd killed a person they'd have been charged with murder, but what if they caused a World-Wrecking Wave and spoiled the lands on top of the already uncountable death toll - how do you punish that? Good question, because often crimes with No Adequate Punishment are so unthinkably evil, bizarre, or stupid that literally no one in a position to mete out justice has had the forethought of what to actually do if someone went and did them.
Don't expect this to mean that they get Off on a Technicality since there Ain't No Rule though, because The Villain Must Be Punished. In most cases, people who commit crimes like these are left to deal with the consequences of their actions, charged with something else in an attempt to at least get some measure of inadequate justice, or just outright killed or given a Longer-Than-Life Sentence to put a stop to further crimes on the pile. It's not justice, because their crime is such that there is no adequate justice to be had, but it's an attempt.
Reminder: If a crime has a "The harshest punishment imaginable" it is not an example of this trope. On the other hand; If "The harshest punishment imaginable" is invoked as a Plan B in a vain attempt to cover the crime, it is an example.
Contrast Failed Execution, No Sentence, in which the law does has an "adequate punishment" (in this case, death), but the fact that the executionee survives leads to the law being at odds of what to do, and There Should Be a Law for when someone believes what they have come across should be illegalized and punished by law, but isn't. May lead to an Obvious Rule Patch being subsequently applied in the form of a law specifically designed to mete out adequate punishment. Sub-Trope of Language Equals Thought, and related to Moral Event Horizon for actions which might have adequate punishment, but still serve to prove to the audience that there is no coming back from villainy for the character committing them.
- In Astro City, Infidel's crimes include laying waste to the entire world and destroying it at least once. Unfortunately, he has been involved in so many historic events (including several in the future) that his longtime enemy Samaritan has been unable to come up with a punishment that would suit the crime without damaging the timeline. On the other hand, Infidel has been unable to find a way to kill Samaritan without causing similar damage. As a result, they've been at an impasse for years, so Infidel has agreed to go into retirement in a pocket dimension, while Samaritan agrees not to interfere with whatever he does there... for now, anyway.
- In Closely Watched Trains, a womanizing telegraphist stamps the legs and buttocks of a female co-worker using rubber stamps from the train station they work in. When the girl's outraged mother sees them, he takes her to the police and courts, who reveal that they can't do anything because he never forced or threatened her. Finally, a Nazi Party official (the film takes place in occupied Czechoslovakia), upon seeing that the stamps are written in German as well as Czech, has the telegraphist charged with "Desecration of the German Language".
- In Harry Potter creating a Horcrux is considered the ultimate evil, beyond even using any of the three "Unforgivable curses"note which carry a life sentence in Azkaban with no parole, and yet the Wizarding world has no punishment for creating a Horcruxnote — because creating one involves literally tearing parts off your soul, and they don't know of a way to make the punishment worse than that.
- Implied in The Jaunt by Stephen King regarding a man who shoved his wife into a Portal Door with no exit coordinates. He tried to argue that he couldn't be tried for murder because there was no proof that the woman was dead, but the jury considered how infinitely worse it would be if she wasn't and ordered his execution anyway.
- In Lord of the Rings: Treebeard's reaction to seeing Saruman having chopped down a good portion of his home forest lets the reader know just how unspeakable an action it is. The ents end up resorting to a Neutral No Longer and enacting Gaia's Vengeance by attacking Saruman's city of Isengard to, at the very least, put a halt to it.
Treebeard: There is no curse in Elvish, Entish, or the tongues of men for this treachery.
- In the Star Wars Legends Jedi Academy Trilogy, Kyp Durron stands trial for destroying a solar system. Mon Mothma acknowledges that while this makes him a mass murderer on par with the Emperor, there is no adequate law in the New Republic books to punish such a crime. Not helping is that he was under the influence of the ancient Sith lord Exar Kun (long story, don't ask) which muddies the question of if he was even in control of his actions. Mon Mothma declares that the only person who could make a proper judgement is the ranking Jedi master, Luke Skywalker. The later novel I, Jedi explored some of the massive problems with this decision.
- From Things Fall Apart:
If a clansman killed a royal python accidentally, he made sacrifices of ______ and performed an expensive burial ceremony such as was done for a great man. No punishment was prescribed for a man who killed the python knowingly. Nobody thought that such a thing could ever happen.
- In Rainbow Six, this is discussed by Clark and Chavez in regards to the bio-terrorism plot intended to wipe out humanity to save the planet. Clark isn't sure how they'd even start with a trial for the attempted murder of the entire human race or who would have jurisdiction for punishing them. In the end, when Rainbow assaults the conspiracy's compound in the Amazon, rather than bring in the surviving conspirators to face trial and open the massive can of worms that would entail, he simply destroys their base and forces them to flee into the jungle with little hope of survival.
- In The Hammer of God by Arthur C. Clarke, The Reborn — a breakaway sect of Chrislam turned Apocalypse Cult — intentionally sabotage the effort to divert the asteroid Kali from its collision with Earth. The Elders of Chrislam quickly manage to identify the saboteurs and turn them over to the authorities, but nobody is certain of what to do with them — partly because they wouldn't be able to find an unprejudiced jury on Earth or probably even on Mars, but also because nobody can imagine a suitable punishment for the unprecedented crime of terracide. Of course, as is pointed out, the question will be moot if the asteroid cannot be diverted.
- In The Curse of Chalion attempting to use death magic to kill someone is punished by execution. However, successfully using death magic to kill someone carries no penalty, since successful death magic a) is technically a "death miracle", and thus sanctioned by the gods, and b) kills the spellcaster along with their victim, so it's not like you could punish them even if you wanted to. When Cazaril manages to survive performing death magic, it's acknowledged that in theory he's committed no crime, but that might not protect him if the information became public.
- Malcolm in the Middle has a comedic version of this show up in the episode "Motivational Seminar": Reese joins a pack of dogs, and goes on a destructive spree after they make him his leader. He ends up being caught by the police in a chicken coop and brought back to his parents which leads to the following comment from the arresting officer:
Police Officer: It's hard to know exactly what happened, ma'am. He and his friends appeared to have had themselves quite a little party. They just don't train ya to handle a scene like that. The law's a little murky in this area, but when we figure out how to charge him... I'll be back.
- The Star Trek: The Next Generation episode "The Survivors". After investigating some strange occurrences on a seemingly-abandoned colony, the crew learns the truth from its Sole Survivor, a man named Kevin: he is actually a nigh-omnipotent immortal alien, who decided to live among the human inhabitants of the colony as one of their own. When the colony came under attack by a cruel, warlike species known as the Husnock, he tried to ward them off nonviolently — but this only furthered the Husnock's aggression, leading to the destruction of the entire colony. Overcome with grief and rage, Kevin proceeded to exterminate all 50 billion Husnock in the galaxy with a single thought in retaliation. The subsequent realization of what he'd done made him decide to live in self-imposed exile within the ruins of the colony, with only an illusory recreation of his dead human wife as company. Picard is utterly stunned and concludes that not only does the Federation not have any laws befitting of Kevin's crime, but even if they did they have no power to actually enforce a punishment on such a powerful being, and he ultimately decides to simply leave Kevin to his solitude.
Picard: Captain's Log, stardate 43153.7 — We are departing the Rana system for Starbase 133. We leave behind a being of extraordinary power and conscience. I'm not certain if he should be praised or condemned; only... that he should be left alone.
- On That '70s Show, Kelso enrolls in the police academy and does pretty badly on a test. He and the others break into the office that night to alter the answers only to get caught. The officer who catches them tells him there's no punishment for what he's doing because it was thought there was no one stupid enough to do it.
- Torchwood: Miracle Day: Because no-one can die anymore, many laws regarding life and death are rendered useless. A man strangled his wife into brain-death. Since she isn't dead and no-one can die anymore, he can't be charged with murder or attempted murder. Assault is the only thing he can be charged with.
- The Hanar of Mass Effect apparently had no idea what to do when Jack Colony Dropped a space station onto their moon hard enough to make a new crater, and so they just charged her with "vandalism" instead — the same kind of charge one would get for breaking a couple windows, which makes it stand out on her List of Transgressions as being a case of Poke the Poodle.
- Planescape: Torment: If The Nameless One tells Vhailor that one of his previous incarnations murdered someone (a death sentence in Vhailor's book) but he's since lost his identity and can't recall anything of his previous life, Vhailor will ruminate on the matter and decide that there is no suitable punishment. He subsequently decides that The Nameless One's amnesia in itself serves as punishment — the one who performed the actual murder is "dead" in a manner of speaking.
- The Order of the Stick: Vaarsuvius killed a quarter of all black dragons, and everyone related to them, including innumerable humans, including the entire Draketooth family. Roy tells V that he's incapable of either counseling or judging the elf. And when V insists, Roy goes into detail as to why he can't advise the elf: The legal issues would take an army of lawyers to sort out, and morally/ethically, the harm V caused would likely defy any price V would be capable of paying.
Roy: This is way over my head. It's too big.
- Draco was the first legislator of Athens and wrote the law so the punishment was death even for minor crimes (hence why harsh laws may be described as "Draconian"). According to Plutarch, Draco openly admitted the laws weren't fair because major crimes received the same punishment as minor ones, but he had no idea for A Fate Worse Than Death to punish the major crimes, and thus death, while inadequate, was still the closest it could get.
- According to Herodotus, the Persians believed that no man since the beginning of time had ever killed his own father, and that whenever this appeared to happen, it was evidence that the patricidal child was actually an impostor or changeling.
- The history of "crimes against humanity" started with the abolition of the slave trade during the 19th Century, but was amended to include genocide after the Ottoman Empire's systematic murder of Armenians during the First World War and Nazi Germany's own murderous campaign against the Jews during the Second World War, the scale of which was never really seen before. The latter horror actually gave rise to the very word "genocide" to refer to it.
- The ILOVEYOU virus, which was created in the Philippines on/after 2000, left Philippine law enforcement stumped since at the time, there was no suitable law that they could use to charge the creators of the virus. The options at the time was to either charge for the use of prepaid internet cards to access the internet (which was barely related to the actual virus), or for malicious mischief (which needs to prove intent, and one of the creators told law enforcement that he released the virus by accident). The lack of a proper law forced the National Bureau of Investigation to have the creators released with no charges, and later resulted in the passing of the E-Commerce Law to address hacking/malware problems.
- In Canada, Gillian Guess had sex with gangster Peter Gill while serving as a juror in his trial, which didn't have a specific law against it because no legislator had imagined that a juror would do something that stupid. They eventually nailed her on a generic "obstruction of justice" charge. Incidentally, while she got Gill off on his own trial* , he was later convicted of obstruction of justice for screwing Guess.