A Video Game enemy which has to be defeated quickly, lest it become more dangerous. Unlike a Time-Limit Boss, failing to defeat them within a certain amount of time rarely leads to a Game Over (unless the player is careless), but can make things harder for the player in a number of ways:
- Calling or creating more enemies after a certain amount of time or Reviving Enemies who get back up if you haven't defeated their fellows quickly enough after them.
- Buffing itself gradually as time passes, becoming especially dangerous if the player lacks a Status-Buff Dispel or if the buff cannot be dispelled.
- Powering up into a stronger form if the battle drags on (this might lead to Do Well, but Not Perfect if the stronger form has a Rare Drop or other reason to challenge it).
- The enemy starts off with a weapon which is quite inaccurate, but over time the weapon's accuracy gets more and more buffed, until eventually it is almost guaranteed to strike with a lethal attack.
- Using a highly damaging attack which takes a few turns of prep (this type of enemy often runs away after doing so). Magic using enemies who need to build up enough Mana Points (by recovering them, or absorbing them from the player with an attack) before they can cast their spells are a specific variant. An Action Bomb is frequently an example.
These changes can either keep building up or they could happen all at once after a set amount of time/turns (or something in between, with the enemy getting stronger at regular intervals). This makes for a slight difference in strategy, as while the former is best defeated as quickly as possible, it might be wiser to defeat the latter as efficiently as possible within the time limit.
Sister Trope to the Time-Limit Boss (when failing to defeat them in time is an instant game over), Boss Arena Urgency (when the area the battle's taking place in is getting more dangerous) and Metal Slime (which costs the player a reward if it isn't defeated quickly instead). Sub-Trope to Gathering Steam. Contrast Turns Red. Compare Stalked by the Bell and Timed Mission, which share a similar relationship to this and Time Limit Boss. If you need to clear away your enemies' support to make things easier, you may need to Shoot the Medic First and / or Shoot the Mage First. The Virus (especially the zombieism variants, given that a lone zombie may not pose a great threat, but it will infect others if not re-killed) is often a meta example, as the longer it spreads the more victims fall to it (and the more of a threat it becomes).
Don't even think about attempting Victory by Endurance on them.
- The Final Boss of Ittle Dew has a phase where he summons Petal Slugs over time. If left unchecked and this phase isn't defeated quickly, they can turn the boss arena into a Bullet Hell.
- Used for story purposes in NieR: Automata when you first fight Adam. He starts off as a barely functional, stumbling boss. But as the battle drags on, he analyzes what 2B and 9S do in order to gain more skill, which in the game looks like he's leveling up.
First Person Shooter
- In Borderlands 2 there are a few enemies which can grow into more powerful forms if they're left unchecked:
- Raging Goliaths are what happens when a Goliath's helmet is shot off of him. These crazed mutant bandits become consumed by anger and start attacking anything and everything unfortunate enough to be near them all the while screaming his head off and laughing. For every kill they get they gain experience points to level up and when they do they get much bigger and stronger, ultimately transforming into the GOD-Liath. Players, if they're big enough Badasses, can farm them for loot and experience points.
- Varkids turn into cocoons, which spit out progressively more and more powerful forms. Unlucky (or lucky, if they're farming it) players might end up fighting Vermivorous the Invincible.
- The "Tiny Tina's Assault on Dragon's Keep" DLC has Orks, which grow even more quickly (and instantly), meaning the player is likely to end up fighting (or running from) a Grand Duke of Ork.
- The Pain Elementals from id Software's Doom series are Mook Makers which spit out endless amounts of Lost Souls, potentially creating a swarm of them if left unchecked.
- The Final Boss in Duke Nukem 3D is the alien queen, who gives birth to a dangerous drone every thirty seconds. Extra difficulty comes from the battle being underwater: once the player's air tank runs out, he's compelled to surface for air periodically, during which one or two new drones will be spawned.
- The Monster in Evolve. It's initially weaker than the Hunters, but if it gets to eat enough and evolve once, it becomes larger, stronger and able to fight on even terms with them. If it evolves again, it becomes stronger than the Hunter Team.
- Letting an Engineer robot get set up in Team Fortress 2's Mann vs Machine mode means the robots get free teleports, cutting down the time you have to prepare for each spawned wave. Worse, they're invincible when spawned, so you could have two dozen Scout robots run in with a bomb in their midst and you might find yourself quickly overwhelmed.
- Certain bosses in World of Warcraft have an "enrage" mechanic, which means they become much more dangerous if the battle drags on. For example, Beth'tilac has an area of effect spell that gradually increases in damage every time it's cast.
- Two of the bosses in Toontown Online, and, by extension, the fan servers, have so-called desperation modes, which crank up the difficulty as the battle drags on:
- The VP's stun time drastically shortens, making him much harder to knock back.
- The infamous C.E.O. After 20 minutes in the final round, one of the conveyors delivering healing snacks to the players will be disabled, and his attacks will become stronger. After 30 minutes, both conveyors will be disabled, his attacks will become even more powerful, he will attack more often, AND he gains a movement speed bonus.
- Elsword: The Bonus Boss Alterasia Type-H is infamous for this. He's surround by constantly spawning Alterasia Spores which periodically heal him. Failing to stay on top of them can cause him to be healed constantly.
- Final Fantasy XIV has various mechanics for bosses and other fights that fall in this category
- All of the Extreme/Savage difficulty and some endgame normal mode Primals and Raids have an "Enrage" mechanic where if you take too long, the boss will simply One-Hit Kill the party, usually with an arena-wide AOE they've done before.
- If somehow the party survives, the boss typically spams the attack until the party is dead.
- Several bosses spawn adds that makes it harder to fight the boss, either by attacking the players, increasing damage the tank takes (straining the healers), or giving the boss a permanent buff if left alone.
- Some bosses apply debuff stacks. The most famous of this are the bosses from Aurum Vale, which require consuming respawning Marbol fruits during the fight to stay alive
- Quite a few bosses have a phase where they build up a meter. The more the meter fills up, the more damage it does up to a party wipe if it gets full.
- Inverted if you're fighting against some Extreme Primals unsynced where you can kill them quickly. However, if you bring their HP down too fast before performing a mechanic, they becoming invincible and start spamming their ultimate attack.
- All of the Extreme/Savage difficulty and some endgame normal mode Primals and Raids have an "Enrage" mechanic where if you take too long, the boss will simply One-Hit Kill the party, usually with an arena-wide AOE they've done before.
- Warframe: Garuda weaponizes this with her passive ability, Death's Gate: The lower her health is, the more damage she does. So her playstyle is very much a high risk, high reward one based upon effectively managing her health with Blood Altarnote and energy with Bloodlettingnote . When done correctly, though, anything between Garuda and her objective may as well be bugs fighting a blender.
Combat Flight Simulator
- The Arclight Electromagnetic Launcher on Mihaly's X-02S Strike Wyvern in Ace Combat 7: Skies Unknown becomes increasingly accurate during the fight, as the X-02S's onboard systems become better equipped at tracking Trigger's aircraft; If the player takes too long to shoot down Mihaly, that accuracy will hit 100%, and given that the weapon can reduce the player's health to a measly 1 point from just a single shot, Trigger's defeat at the hands of the EML is assured from here on out.
- Infinity Mijinion from Mega Man X6 will periodically duplicate himself during battle (or when he's struck by a powerful attack). He can potentially fill an entire screen with his copies if you take too much time, making him harder to kill.
- The Binding of Isaac: Homunculi and Begottens start out chained to walls or rocks, only capable of running at the player in short range. If enough time passes without killing them, they break their chains, and each of them gains a new trick making them more dangers. Homunculi will leave damaging creep on the floor while they run and shoot six blood shots when they first break, while Begottens turn the screen dark and often turn invisible.
- The Tonberry from the Final Fantasy series will usually spend several turns approaching before using its signature "Everybody's Grudge" or "Karma" attack, which deals damage for every enemy defeated so far to one target. This attack can be One-Hit Kill for characters that have been murdering tons of enemies up to the point they can encounter Tonberries, which usually near the end of the game.
- Kingdom Hearts II: Lexaeus' gimmick for his Bonus Boss fight in the Final Mix version is that he has a power level that determines his damage output. He starts off doing so little damage that even if you're Level 1 he's completely non-threatening, but as the fight goes on he will occasionally power himself up and do more and more damage.
- In Pokémon:
- Regigigas has the "Slow Start" ability, which means that it spends the first five turns of a battle with reduced speed and attack. After this, the effect wears off and its real stats come into play. Seeing how the metagame is all about speed or stalling this handicap becomes more of a hassle than intended.
- Certain moves become more powerful if they gain momentum. Rollout, Ice Ball, Fury Cutter, and Rage will all become more dangerous if the foe can't be stopped, and they're allowed to use it multiple times in a row. Bugsy and Whitney both rely on this strategy in Gen II with a Fury Cutter Scyther and a Rollout Miltank respectively.
- Pokémon with the Moxie Ability. This Ability causes the Pokémon that has it to gain one stage of an Attack buff (a +50% boost per stage) every time it knocks out another Pokémon. If not stopped, these Pokémon will steamroll their way through the opposing team, especially if they can naturally increase their Speed. Magearna's signature ability, Soul Heart, is a Special variant of this, meaning it cannot even be slowed by Intimidate. Furthermore, it triggers whenever another Pokemon is knocked out - Magearna not only does not need to score the KO by itself (for example, if another Pokemon was knocked out by poison or burn, or by another Pokemon's attack), but it also triggers if a teammate was knocked out, making getting boosts incredibly easy to pull off.
- The ability Beast Boost is this on steroids. Unlike Moxie or Soul Heart, which can only boost a single stat, when a Pokémon with Beast Boost knocks out another Pokémon, the Beast Boost user gains one stage of a buff IN ITS HIGHEST STAT. With proper Min-Maxing, a Beast Boost Pokemon can be tailored to boost whichever stat the player wants it to. The more offensively-inclined users, like Pheromosa and Xurkitree, can boost their already strong Special Attack stat to ridiculous levels, while more defensive users like Celesteela and some variants of Nihilego can boost a defensive stat instead, making it even harder to take down.
- Blaziken is banned from competitive play for good reason. One of its abilities, Speed Boost, causes the Pokémon to gain one stage of a Speed buff at the end of every turn, which means it only takes about a turn or two to outspeed almost any Pokémon in the game.
- The ability "Moody" is even more broken than Speed Boost. At the end of each turn, it randomly raises one stat by two levels, while another one is randomly decreased by one level. It can also raise/lower accuracy or evasion, and if evasion gets raised it essentially works as free Double Team, so good luck hitting a monster that on average gets stronger each turn. This ability made Bidoof completely broken, therefore it is no surprise it got banned in competitive play as well.
- Any Pokémon equipped with the rarely-seen item Metronome can become this, as the Metronome's effect is to increase the damage done by a move for each consecutive turn it's used. If used in conjunction with the aforementioned moves like Rollout, Ice Ball, and so forth, both damage multipliers kick in, turning these moves very powerful very fast.
- The Void Shadows at the end of Pokémon Super Mystery Dungeon's Reverse Mountain have the ability to duplicate themselves, a decent amount of HP, an attack that affects your entire party, and no type. If you don't take them out before the two Mega Gengars and the Mega Tyranitar, you're pretty much screwed. It doesn't help that the three Megas have an ungodly amount of HP, the Mega Gengars have Confuse Ray, and the Mega Tyranitar is very bulky.
- Bosses in Diablo III generally adopt tougher tactics at certain health thresholds, or make the arena slowly more hazardous. However Belial has one attack that peppers the arena with randomly-placed explosions, of which there are more each time he does it until they become unavoidable.
- Every enemy in Breath of Death VII and Cthulhu Saves the World gets stronger the longer the fight drags on, pretty much ruling out any turtling strategy.
- The Bonus Boss in Lufia II: Rise of the Sinistrals is completely harmless for three turns, saying supportive things and even healing the party. On the fourth turn, he casts a spell that inescapably causes a Total Party Kill, though thankfully it doesn't cause a game over, merely sends everyone back to the beginning of the 99-level Bonus Dungeon without their final reward.
- The optional boss Mother Brain in Chrono Trigger can be this. She starts the battle with three Panels that will heal her every turn for a moderate amount of HP. If you kill all three of them, she Turns Red, getting increased stats and a powerful attack-all spell. Furthermore, her stats will continue to climb at a rapid pace. The longer the battle goes on, the more damage she'll deal and the less she'll receive, and after a few rounds she's practically unkillable. It's generally recommended to avoid this phase entirely by killing only two Panels and leaving the third alive (it will die when she does anyway).
- Bonus Boss Lucifer in Devil Survivor has to be defeated quickly once he goes into his second form, as he will periodically cast Megidoladyne, an Almighty-elemental spell that targets everyone in all of your parties on the map and does 50% more damage with each successive casting, until it inflicts four-digit damage in a game where player-controlled characters can each only have up to 999 HP.
- Etrian Odyssey IV introduced Rare Breeds, glowing variants of normal Mooks and F.O.E.s that get stronger the longer you leave them alive. They also give your party much more experience points than normal, provided they don't run away first.
- The final boss of "The Answer" chapter in Persona 3 FES Erebus will use an attack called Dark Embrace periodically. Each time is is successfully used it will increase in damage until it becomes impossible to avoid a Total Party Kill. It's more downplayed than other examples however because it's possible to prevent it using it at all by inflicting enough damage while it's charging. Not that it explains that.
- High-level paladins in Warcraft III have a shield that makes them invulnerable and a mass resurrection ability. If not neutralized quickly, they spend the fight unable to take damage and bring back half a dozen dead units at full health.
- The Firelord's Incinerate ability deals ever-increasing damage with every attack.
- Plague Inc. has two of them, both being antagonists in two different game modes:
- Z-Com in the Necroa Virus mode. Every fortification of theirs will grow stronger over time, allowing them to combat your zombies more easily. They start off with one fortification, and if not dealt with in time will send planes over to other countries to establish more fortifications that will send more planes if not dealt with. As such, it's essential to get your zombies to take down their fortifications quickly.
- Templars in the Shadow Plague mode. Like Z-Com, the Templars will become stronger in their country over time and give them better attacking power against your vampire, which makes it important for the vampire to remove them quickly. Unlike Z-Com they can't establish more bases, but instead grow stronger each time another Templar base is destroyed.
- In a different sort of enemy, the Bio-Weapon plague will get increasingly deadly no matter what you do, and quickly becomes so quick at killing it can't infect fast enough and burns itself out. The key is to keep developing supression genes that will keep the lethality down for some time at least, until you've managed to infect enough people. And, if you infect everyone, you can just bring back all the lethality back and then some by unlocking the Annihilation Gene, which can and will kill the world in two weeks if everyone's caught the disease.
- In the remake of Resident Evil, dead zombies who are not decapitated or burned will later come back to life as deadly Crimson Heads when the player returns to the area after a certain amount of time or if certain Event Flags are triggered (although, there's at least one corpse that the player can't do anything about, and a boss battle with the Super Prototype crimson head that can't be avoided).
- Dungeons & Dragons 1st Edition supplement Deities & Demigods Cyclopedia, Greek Mythology chapter. The giant Antaeus grows stronger each round he fights as long as he's touching the ground. He starts with the strength of a hill giant (19) and gains the strength of the next larger giant size each round of combat until he reaches the strength of a titan (25). This allows him to do increasingly more Hit Points of damage when he hits. In addition, each time he grows he regenerates all lost Hit Points of damage and gains an additional 25 Hit Points, making him tougher to kill. So when he starts to fight he has 100 Hit Points and a Strength of 19, doing 2-16 Hit Points of damage per hit. After 7 rounds of combat he has 250 Hit Points and a Strength of 25, doing 8-48 Hit Points per hit.
- In Magic: The Gathering, Primordial Hydra has power and toughness that double every turn, and after it has been on the field long enough to get 10 power, it has trample, making it impossible to chump block.
- In a similar vein, Kalonian Hydra enters with respectable stats that double every time it attacks. And unlike Primordial Hydra, it always has trample.
- Figure of Destiny and Warden of the First Tree start off as 1/1s, but must be killed quickly before their controller begins to spend the mana to transform them into their stronger forms over time.
- Betrayal at House on the Hill's tentacles scenario summons several monsters that start out pretty wimpy, but if the players don't manage to win the scenario promptly quickly become extremely dangerous, increasing in strength and speed every few turns.
- The Final Boss of XCOM 2 will keep summoning reinforcements every turn, forcing you to kill them quick or be swamped by mooks.
- The Final Boss of Fire Emblem Awakening has a similar gimmick, with it summoning several enemies around the map every turn. Including high mobility enemies like Wyvern Riders. Thankfully the mission ends in victory if the boss itself is killed.
- Plants vs. Zombies: Heroes: Several Plant and Zombie Teammates will keep buffing themselves each turn if not removed from the battlefield. The Pea Pod and Team Mascot will give themselves +1 strength and +1 HP every turn, while the Doubled Mint's stats double each turn. Many cards with the "Dino-Roar" ability will also have this trait, usually buffing themselves or other teammates whenever a card is drawn by their side.
Wide Open Sandbox
- One of the enemies spawned by the Vortex Pillar is the Alien Larva, which start out weak, but grow in to the stronger Alien Hornet, then become the deadlier Alien Queen. Each form deals more damage than the last and the Queens can shoot projectiles that screw up the player character's movement. Queens can also spawn Larve when killed, starting the cycle all over again.
- The Star Cells spawned by the Stardust Pillar start as standard Asteroids Monsters, splitting in to a few smaller versions of itself when damaged. Should the smaller versions live long enough, they each grow in to full-sized Star Cells that once again split when damaged, which can quickly overwhelm a player.
- The Juggernaut role in Town of Salem grows in power and gains a new ability with each successful kill they make. After the first kill they will be able to attack every night, after the second they gain basic defense, the third they will kill each other person who is targeting theirs, and the maxed out Juggernaut will kill any player while ignoring any defense or heals. The only role who can survive the last attack is Pestilence, who cannot be killed at night.
- The co-op bosses in 100% Orange Juice! use a random card every turn to make things harder for the players, and as the match progresses these cards will gradually be swapped out for stronger ones. Each boss also has their own method of becoming more dangerous over time, such as Star Devourer dealing more damage to players in battle as she steals more stars or Big the Johnathan covering the board in damage panels with his dive bomb attack.
Non-Video Game Examples
- The Incredibles: The Omnidroid is stated by Mirage to be an example of this trope:
Mirage: I've got to warn you. It's a learning robot. Every moment you spend fighting it will only increase its knowledge of how to beat you.Mr. Incredible: Shut it down, do it quickly, don't destroy it.Mirage: And don't die.Mr. Incredible: Great. Thanks.
- Lung in Worm gets more powerful the longer a fight continues, growing wings and increasing his pyrokinetic abilities.
- A common misconception was that Broly from the 8th Dragon Ball Z movie had his ki continuously increase while he was in his Legendary Super Saiyan form, based on a misinterpretation of one line he said. In Dragon Ball Super, characters like Hit and Ganos were introduced who actually fit this better, continuously improving throughout the fight.
- Hit and Ganos become increasingly lethal in the exact opposite way. Hit becomes more skilled and improves his Time-Skip, but he doesn't gain any actual physical improvement; meanwhile, Ganos's skill stays the same, but his strength, speed and endurance increase constantly.
- The new canon version of Broly from Dragon Ball Super: Broly on the other hand, does have such an ability. When he's introduced, he's never been in a fight before. It's quickly revealed that when he fights he constantly grows stronger. And does it so quickly that he surpasses Super Saiyan Blue Goku and Vegeta as well as Golden Frieza, and it's speculated that he could even be a match for Beerus. This rapid increase in power means that Goku and Vegeta are forced to become Super Saiyan Blue Gogeta to win.
- In JoJo's Bizarre Adventure: Stardust Crusaders, this is what makes Anubis such a threat to the heroes: Not only can he learn how to counter any attack done to him right after it connects, but he grows faster and stronger each time he fights.
- A common problem in So I'm a Spider, So What?, especially with boss monsters. Since continual exposure to threats allows you to unlock resistance skills, Kumoko has to kill her foes quickly before they grow immune to what she's using. Fortunately this goes both ways, as Kumoko also grows in power as she fights.
- The Ranma ½ fan fiction Relentless revolves around one of Happosai's sins (insulting a witch by stealing her undergartments) coming back to haunt all of the cast in the manifestation of a summoned spirit that is implacable and, worse yet, capable of adapting to all attacks that can injure it. By the time the Nerima Wrecking Crew finally figure out a way to kill it with magic in the final act, it is every bit as epic a battle to put it down as you would expect it to be.