My Defense Need Not Protect Me Forever

Two sides will be fighting, with one side (usually the villain) holding the upper hand. The hero is left relying on his gradually weakening defenses and it appears that our hero is about to be destroyed. The villain says something like, "You can't hold out forever," and then...

Suddenly, the villain is promptly defeated. It may be because a group of reinforcements arrived in time to take him down. It may be because the hero had to take time to prepare the attack needed to take the villain down.

For the hero reveals that he didn't need his defensive measures to cover him forever; he just needed the given time to set up what was needed to defeat the villain.

A subtrope of Tempting Fate. See also Defensive Feint Trap, Just Toying with Them, and contrast with Exactly What I Aimed At, where the hero has apparently missed but turns out to not to have needed to hit the villain.

Anime and Manga

 * In Saint Seiya, the Perseus saint tells Shiryu he can't block his Medusa shield forever. Shiryu was unable to attack effectively at the moment,.
 * In the first game of Eyeshield 21, Hiruma reminds the team of mostly rookies that they only need to cover their ace running back for 0.5 seconds, which would give him enough time to get a significant amount of yardage.
 * In Naruto, during an anime filler, Yamato dodges every attack from a Earth element user, because he was waiting for his preparations to complete for using an Earth technique.
 * In Code Geass R2, the Black Knights fight a defensive battle against the corrupt eunuchs who rule the Chinese Federation. They get trapped in a mountain cave and hold out until Lelouch's Engineered Public Confession causes the oppressed masses to rise up, turning the tide of the battle.
 * The basic concept behind the Soaring Dragon technique in Ranma ½: Get your opponent mad and let them keep attacking while you dodge and lead them around in a swirl without getting mad or attacking yourself, even if you take a few hits. This ends up "collecting" the expended "hot" chi energy of the opponent, and allows the user to mix "cold" chi in the mix, creating a tornado of energy and tossing their opponent into the air.
 * Rurouni Kenshin has defeated a few opponents this way, and buying time for a counterattack was how Aoshi's Elite Mooks made a Heroic Sacrifice.
 * In Dragonball Z, Goku has tried everything else to no effect against Frieza, and has to resort to his trump card, the Spirit Bomb. The problem is, it'll take him several minutes to create a big enough Spirit Bomb, and he has to stand motionless and let Frieza pummel him while doing it. This means the much weaker Piccolo is forced to step in and fight a losing battle to keep Frieza distracted long enough.

Card Games

 * Very common in Magic: The Gathering, particularly with combo decks facing creature aggro decks. They slow down their opponent with counterspells or creature removal long enough to set up a devastating move. The right card can often totally shift the course of a game.

Film

 * This gradually becomes the strategy of the entire British army in Waterloo. Hold off the French army just long enough for their Prussian allies to join them and then overwhelm the French. Despite the fact that the French look set to gradually wear out the English, it finally works.
 * Pretty much a staple in any Star Trek film: The Enterprise's shields will be as useless as wet tissue, and yet the crew still finds a way to come out on top (Heat-seeking torpedoes, self destruct mechanisms, turning the enemy's own weapons against them...)
 * During the final space battle in Galaxy Quest, the Protector never fires a single shot at Saris's ship (in fact, the Protector only ever fires once in the film, at the very beginning). Instead, The Captain has the pilot navigate into the nearby mine field, while diverting all available power to structural integrity in order to survive Saris's Macross Missile Massacre. By the time he turns his ship around to face Saris, the Protector's armor is completely gone, which means a single volley would finish it off. However, the ship is . Cue explosions.
 * In Real Steel, Atom can take a lot more damage than an average fighting bot thanks to him being built specifically for sparring, but even his endurance is taxed during his prize fight with Zeus, whose fights never last more than 1 round. When Zeus once again starts pounding Atom relentlessly, Charlie just does his best to keep Atom's vital areas covered from the worst of it without hitting back. Eventually, just as Atom's endurance is about to give out,, allowing Atom to take the initiative. Rope-a-dope, Rockem-Sockem-Robots style.

Literature
"Mr. Prosser: "You can't lie in front of the bulldozers indefinitely." Arthur Dent: "I'm game, we'll see who rusts first.""
 * This is a recurring motif in The Lies of Locke Lamora by Scott Lynch. Locke doesn't have to hold out forever, only until Jean gets to him...
 * From the beginning of The Hitchhiker's Guide to the Galaxy:


 * It doesn't really work.
 * Well, if Arthur had stayed there another half an hour, the planet would have been destroyed before Prosser could get around to bulldozing the house.
 * In Heroes of the Valley by Jonathan Stroud, one of the titular heroes says almost that exact phrase to the others as they are overwhelmed in their final fight to the death against a nigh unstoppable enemy.
 * In Miya Black, Pirate Princess IV: This Impossible World, This Impossible Girl, Miya utilises this tactic twice; she almost gets herself killed in the fight against Flynn before ending it with a single unspectacular move ("You show off. I watch."), then reveals that the fight was both a distraction and a delaying tactic.

Tabletop Games

 * Rather unique defense arrangement of 2e Alchemical Exalted: my power shield fails but perfectly blocks, my last HPs don't go out Terminator-like (the appropriate charm has both a development and fanon name Terminator Charm)... all the while I keep coming at you. The catch? Your defenses cost essence, and mine didn't, so if your pool is out before my layers, guess what happens?

Video Games

 * Most defend or hold-the-line missions in RTS is this, seeing as the usual result is either a counterattack or a straight-up victory.
 * The final level of Warcraft III has the allied races desperately trying to hold off Archimonde so Malfurion can set a trap for him.
 * Several timed missions in that series and in StarCraft involve stalling until help arrives or a devastating attack can be prepared.
 * However, in one of the early missions, if you build up enough defenses, they really can protect you forever.
 * Starcraft II, as well. In fact, one mission is designed to specifically test if you CAN do this. It only ends when you die.
 * It should be noted that this is one of the few missions you play as the protoss instead of your usual terran army that excels on turtling.
 * In Dragon Age Origins, the king's strategy at the battle of Ostagar is make the main force hold the gates while a smaller force ambush them from behind and turn the tide of the battle.
 * A strategy sometimes used in RPGs, where certain powerful abilities need time to charge and others protect you for a limited period of time. By combining them, one can protect oneself from harm while charging the powerful attack that will defeat the enemy swiftly and surely. Alternately, the shield protects against a single attack, and then breaks. You can use it against a once-off instant death spell or similar lethal attack. A final method is to get hurt by a weak attack, then (ab)use the resulting Mercy Invincibility to walk through attacks or obstacles that would otherwise have killed you. Once passed, they have no chance to hurt you again.
 * Many speedrunners save their protective measures for such occasions, where speed is more important than killing all the enemies.
 * In Team Fortress 2, the Scout's secondary unlockable is the BONK! Atomic Punch energy drink. When you drink it, the Scout becomes invincible for 5 seconds but cannot attack. ...Except for the taunt kill with an incredibly long wind-up time. A relatively easy way of getting the Scout's taunt kill achievement is therefore to drink BONK!, then quickly approach an enemy from behind and start the taunt. Even though BONK! will wear off just before the swing finishes, your enemy will die instantly from the attack and thus you don't need the protection anymore. Unless the rest of the team is nearby, which they most likely will be.
 * Tales of Vesperia has a villainous version of this with
 * Most Tank-type characters in City of Heroes have a power that gives them a lot of bonuses and power, but only for a few minutes, after which you'll be drained of endurance and/or other abilities. The reasoning is this very trope: You need those extra defenses just for a minute or so, after that it won't matter.
 * The Legend of Zelda: Skyward Sword has another villainous version where

Web Comics
""The laws of probability dictate that you will fail a Will save before I run out of Suggestion spells." "Clever. However, there's one number you've failed to include in your analysis. Your hit point total." *chomp*"
 * Order of the Stick has V sum it up: "True, except that we have no need to continue this exercise indefinitely."
 * Roy of Order of the Stick also fights such a battle.
 * And again.
 * This example could also be seen as something of an inversion if viewed from Sabine's perspective; her Attack did not protect her forever... and the backup plan failed spectacularly.
 * V also was on the receiving end of this trope once.

""Ha! You can't hide forever!" "She doesn't have to.""
 * Girl Genius:


 * This one is subverted, as it turns out that Agatha has to hide after all.
 * A variation in Tales of the Questor: The only defense against being repossessed that Freeman Downs has is Quentyn going out and trying to find the artifacts, something he may well perish before doing so.
 * Freefall's Sam Starfall plays this trope perfectly straight with a robot that wants to kill him.

Web Original
"Penelope Windsor: "I didn’t have to stay hidden for the entire trip," the mouse explained. "Only for as long as it took for it to be too late to turn back.""
 * Chakona Space: Played with in the hands of a stowaway:

Western Animation

 * Lightning in Teen Titans was fighting Beast Boy, who used his shapeshifting powers to evade Lightning's attacks. Lightning remarked that BB's powers couldn't protect him forever. As soon as he finished, he got rammed by BB.
 * In Justice League, Kalibak was fighting Batman and used this line, but Batman revealed that he was just stalling for Superman. When Supes arrived, he punched Kalibak across the block and said, "For what it's worth, I don't think you could have taken Batman either."
 * The plot of an episode of Gargoyles. Hudson and Goliath are facing an Ax Crazy, laser canon-wielding Demona, and big guy Goliath has been taken down. Hudson protects Goliath, and Demona doesn't catch up to them until dawn; at which point all three turn to stone, and Demona has to face a fresh Goliath when the sun goes down.
 * In Avatar: The Last Airbender, in The Day of Black Sun, Part 2 Azula stalls as the heroes fight her so that she can wait for her firebending to come back.

Real Life

 * "Though effective, appear to be ineffective." Sun Tzu
 * Rope-a-Dope, in boxing.
 * This is the rationale behind #4 of The Thirty-Six Stratagems.
 * Also called the "rope-a-dope," a common Air Combat Maneuvering stratagem which involves flying in a straight climb; theoretically presenting a tempting target for the enemy but in actuality setting them up for a devastating counter-attack when their plane cannot keep climbing as long as yours can.