One of the easiest, and therefore most common, ways to ratchet up the dramatic tension in an action scene is to impose a strict time limit on the heroes. There are a whole host of tropes that branch off from this concept, Race Against the Clock being chief amongst them. The reason why is obvious enough; few things raise the audience's heart rate more effectively than a race against time to disarm a bomb or accomplish some other similarly fiendish task.
Sometimes, however, the heroes aren't the one with the time limit. Sometimes the enemy is the one who has only a certain amount of time, fuel, or other resource before they are neutralized, shut down, or even dead. In these cases, the heroes' goal is not to race the clock, but to stall and wait out the enemy's clock while trying to avoid being captured or killed in the meantime. The heroes are facing a Danger with a Deadline.
The Danger with a Deadline trope covers situations in which an enemy poses a very real and present danger, but only poses a threat for a finite amount of time. After that time is up, the threat is either greatly reduced or completely neutralized. While the exact amount of time need not be known to either The Hero or the audience, it's generally made apparent in some way that the danger does have a deadline. This may be accomplished by dropping hints, saying so directly, or simply making it obvious enough that the audience can figure it out themselves.
While this trope often appears as "the enemy is in a Race Against the Clock," it can manifest in other ways. It may be Exploited by The Hero as a means to evade or defeat an otherwise insurmountable enemy, it can be Played for Laughs by having the enemy run out of time at a particularly awkward or inopportune moment, or it can provide a scare by having the enemy set upon the heroes at the last minute only to fail by a hair's breadth.
While not the most common trope in the world, it appears in almost all narrative-based mediums and still enjoys much use today, especially in cartoons and comedies. In fact, the relatively new medium of Video Games has given the trope a new lease on life, as it can be used to add layers of challenge and/or strategy to certain enemies and boss fights, or at least create some really bizarre Easter Egg situations.
Subtrope of Race Against the Clock. May incorporate elements of Exact Time to Failure. See also Hold the Line and My Defense Need Not Protect Me Forever, which describe strategic answers to this trope. Contrast Time-Limit Boss, Increasingly Lethal Enemy, and Stalked by the Bell, in which the enemy imposes a deadline on the heroes. See also Victory by Endurance, which describes winning by simply outlasting the enemy without any specific deadlines.
As this trope often involves death or the defeat of a major enemy, spoilers are inherent this page and will be unmarked. Reader beware.
- In Berserk, bloodthirsty spirits assail Guts and Casca during the night, thanks to their Brands of Sacrifice. Once the sun rises, however, the spirits disperse. As a result, Guts begins to sleep during the day so he can be ready to protect himself at night.
- In Demon Slayer: Kimetsu no Yaiba, demons are incredibly difficult for humans to kill thanks to having far greater strength, toughness, and speed, nearly limitless stamina, and a Healing Factor unless their heads are cut off. However, all demons are vulnerable to sunlight and will crumble into dust if caught outside at the crack of dawn.
- In One Piece, anyone who drinks Hero Water gains incredible physical strength for a short time, but it will inevitably kill them five minutes after consumption. Alabasta's finest guardsmen drink it in an attempt to defeat Crocodile. Unfortunately for them, Crocodile is well aware of the lethal side effects (thanks, Igaram...) and dodges their attacks and floats away with the powers of his Sand-Sand Fruit, letting them drop dead without lifting a finger.
- Makoto Shishio from Rurouni Kenshin is an incredibly powerful warrior, but due to being burnt to a crisp earlier in life, he can now only engage in strenuous activity (like swordfighting) for a very short period of time due to his extreme hyperthermia. He physically and mentally starts breaking down after 15 minutes of activity due to his extreme body heat, and after 25 minutes, he bursts into flame and dies.
- "The Story of the Yara": For whatever reason, the Yara only goes after men who are on the eve of their wedding. Alonzo points out that he's been frequenting the jungle pools on hot nights for a long time, and nothing has ever gone wrong. Julia herself says that the pools won't be dangerous after they marry. However, in the period in between, the Yara is a major threat to Alonzo's life and their happiness.
- A Certain Crazy Christmas Special: The villain is a Bad Santa, a deranged magician who can do anything related to Christmas, but his powers only work during Christmas time. Motoharu suggests simply staying clear of him until Christmas is over, but unfortunately that is not an option since he is actively attacking people.
- Fright Night (1985). The protagonists manage to avoid being killed by the vampire Jerry Dandrige until sunrise. They then rip the coverings off the house's windows and "let the sun shine in", eventually trapping Dandrige in sunlight and destroying him.
- While vampires have historically been considered nocturnal, Count Orlok from the 1922 German horror film Nosferatu is the earliest example of a vampire actually being killed by sunlight. The movie's influence is hard to overstate; even today, a large percentage of vampires in Western fiction are either killed, weakened, or otherwise adversely affected by daylight.
- In A Certain Magical Index, Cendrillon's magic lets her move fast enough to dodge a cluster bombing and automatically readjusts external factors to make her nearly untouchable. However, since her power is based on the legend of Cinderella, her power will fade at both midnight and sunrise. As such, her powers will fade when the sun comes up or if she's presented with something that represents a sunrise or the clock striking twelve, such as changing every nearby clock to show 12:00 or detonating an oil tanker to create a bright flame mimicking the sun.
- Most modern portrayals of werewolves hold that they change back into humans when the sun comes up or the moon is no longer full, so theoretically one just has to avoid being killed during a full moon. While this idea's origin is difficult to track, the earliest known recorded mention of a werewolf transformation being reversible dates back to Ancient Greece, namely the The Histories of Herodotus, although those particular transformations lasted several days. It's worth noting, however, that these "werewolves" were actual wolves; the wolf-man chimera of today is a more recent invention.
- In The Hobbit, Gandalf notices that trolls have caught Bilbo and the dwarves, so from his hiding place Gandalf disguises his voice to keep reigniting the trolls' argument over how to prepare the dwarves and hobbit for eating, stalling for time until the sunrise turns the trolls to stone.
- The Angel episode "Heartthrob" centred on a vampire who had taken a Deadly Upgrade to kill Angel, which would make him invulnerable for six hours, at the end of which he would die.
- Doctor Who: The Family of Blood are a family of short-lived body-snatching aliens. When they start hunting The Doctor, he decides to hide in human form for a few months on Earth in hopes of waiting out their lifespan. This fails to stall them quite long enough.
- On an episode of Red Dwarf, Rimmer is playing chess against one of the automated cleaning robots with full knowledge that while the robot might be able to outplay him, it also begins its work shift in a few minutes meaning it has to leave and thus forfeit the game.
- The Witcher (2019) has Geralt facing down a vicious monster called a Striga that has been cursed to rise from its tomb at night and cause havoc, so he has to keep it out of its coffin until after sunrise in order to defeat it. The effort of doing this nearly gets him killed.
- The Lord of the Rings Online: One possible lieutenant that can appear in skirmishes is the Daywalker Berserker, an armored troll who enters combat with 20 seconds of complete damage invulnerability. Once that expires, they can be hurt and dispatched like any other lieutenant.
- Metal Gear Solid 3: Snake Eater: The boss battle against The End can be won without actually fighting him — you have the option of saving during the battle, leaving the game, waiting for a whole week (or simply advancing the console's clock forward by a week), and then picking up where you left off. The End, who is already well over 100 years old, will die of old age. It's not very sporting or even fun to do, but it works.
- In Phantasy Star Online 2, Gehl Bulfs are flying, nigh-unkillable, intangible Falspawn that deal massive amounts of damage to any ARKS op they come into contact with, chasing them through walls and obstacles to ram them as many time as they can. But they can only last a few minutes at most and can only move in a straight line with short pauses between rushes. ARKS ops are recommended to simply avoid it until it expires by running in wide circles, though a stationary Photon Cannon that can kill the Gehl Bulf in one hit will sometimes be teleported in.
- Slay the Spire: Transients are extradimensional creatures that have near-unkillable amounts of HP, but also have a timer on them that causes them to fade out of existence within five turns, automatically winning you the match. The difficulty is in holding out until then, both battening down the hatches and smacking them around to lower their horrifically high damage.
- In the StarCraft II campaign Wings of Liberty, "Outbreak" takes place on a planet whose star has a very high UV output which burns Zerg units instantly. Thus the level has you bunker down and defend against swarms of Infested Terrans by night (a Zombie Apocalypse in all but name) and attack their bases by day. You can, however, attack during the night if you feel like going for an achievement.
- Played straight in Terraria with three of the five nocturnal bosses (Eye of Cthulhu, The Twins, and The Destroyer), who only appear at night and despawn if the player manages to outlast them until dawn. Subverted with Skeletron and Skeletron Prime; if Skeletron is not killed by the time dawn comes, it sends its head flying into the player at high speed, dealing enough damage to kill the player quickly.
- Discussed and Exploited in Futurama when Zapp Brannigan lists some of his "accomplishments," namely, his method of winning the war with the Killbots. Since the Killbots have a killing quota of 999,999 before automatically shutting down, Brannigan just ordered wave after wave of earth soldiers to go after the Killbots.
- In most Merrie Melodies shorts starring Ralph Wolf and Sam Sheepdog, such as Woolen Under Where, the two characters are expectedly antagonistic towards each other. Until, that is, the end-shift whistle blows, in which they immediately stop whatever beatdown is about to occur, become downright amicable with each other, punch out and go home.