Inigo: I admit it: you are better than I am! Man in Black: Then why are you smiling? Inigo: Because I know something you don't know. Man in Black: And what is that? Inigo:I am not left handed![Switches the sword to his right hand and starts driving him back]
A Combat Trope in which one of the combatants reveals that he's been holding back, but now decides it's time to take it up a notch.
The situation varies from example to example. A common example is for a character to fight with their non-dominant hand, as in the trope-naming example, only to switch back to their dominant hand to gain an edge. Similar to this is pretending that they have a serious handicap, then deciding to stop the charade. It can also go so far as a character revealing that they have always had a superpower which they now decide to exploit, or a Dangerous Forbidden Technique which they now have no option but to utilize.
Villains can invoke this trope, as well.
Has a couple of sub-tropes:
Fai in Tsubasa Reservoir Chronicle begins the series with an elaborate phoenix tattoo which Yuuko demands as his payment for the fulfillment of his wish. Much later, it's revealed that the tattoo was designed to prevent his magic from growing in power each and every time he uses it, as it would otherwise naturally do.
Used in Naruto, when Jiraiya fights Pain: Jiraiya think he's won by defeating Pain's three bodies then it turns out Pain has three more, and one of them can repair the others. Fittingly, he reveals this by ripping off Jiraiya's left arm.
When Pain fights Naruto, he believes that Naruto has used sage mode long enough, and it will expire shortly. It does, but Naruto has got a couple more sage modes stocked up elsewhere. He also generates more sage mode during the battle, while Pain is busy lecturing him.
A, the Raikage, thinks he is still stronger than Bee when Bee challenges him to a Lariat strike. However, Bee reveals he has surpassed him, and completely overpowers him without his Hachibi Cloak.
Also Rock Lee's fight with Gaara. At first, even with his speed, Lee can't get past Gaara's sand defenses. Guy tells Lee that it's time to pull out all the stops, and Lee starts taking off the weights on his legs. No one else thinks this would make much difference, and Gaara's siblings find it outright laughable...and then the weights shake the whole arena and form significant craters when they hit the floor. It turns out they were very heavy. Lee then resumes his attack, even faster than before and able to hit Gaara so fast his sand shield can't move fast enough to block him.
In Magical Girl Lyrical Nanoha StrikerS, the third season of the series, it's revealed that Nanoha, Fate and Hayate voluntarily put limiters on their powers in order to continue working together, officially because of the office politics of having too high a concentration of power in one unit, but actually to disguise the true power available to Section Six, the reactions when the villains found out just how well this worked were priceless. On an entirely unrelated note, Nanoha herself isleft-handed.
As doesExperimental Comic Kotone, but inverted in that Konstantin is left-handed. This is actually a better ruse because 90% of the population is right-handed, no one would notice anything strange if a person was using their right hand.
Karasu in YuYu Hakusho pretends that his power is to make anything he touches explode. Kurama tries to counter by fighting at a distance. But Karasu reveals that his real power is to make invisible bombs that he can move with his mind. BOOM.
Younger Toguro gives us this gem after he's already powered up and begun dominating the fight with Yusuke.
Toguro: What I've been telling you is a hundred percent is really more like eighty-five. (powers up even more)
In Black Cat Volume 2, Train Heartnet reveals that he is not right handed. As a matter of fact, he was originally left handed, learned to wield his pistol ambidextrously, and switches to his dominant hand to increase his fighting potential (i.e., speed and accuracy).
A similar example is Maki in Hayate × Blade, who had always held her sword in her right hand until it was severely injured by her opponent. Another character explains that she had not been fighting with her full power previously, because the manner in which she was gripping the sword was completely different.
Similarly, in The Prince of Tennis, Ryoma plays his first match in canon with his right hand. He manages to upstage his opponent in this state, but eventually decides to reveal that he is not right handed, and completely crushes the terrified opponent. Ryoma is fond of confusing his opponents this way throughout the series.
This is probably the most prevalent in Ryoma's showdown against Yukimura in the finale of the OVA, where Ryoma almost gets out-dueled by the much feared Yukimura, and falls to the ground exhausted, but suddenly wakes up in a Deus ex Machina and out-duels Yukimura in reverse.
Also, Inui purposefully handicaps himself with heavy weights on his ankles, which he later removes to the shock of his opponent. He's not the only one who does so, either; the non-regular Arai also uses weights. As does every other character in the series in at least one match.
This also happens in the second movie, Battle of the British City, where after Ryoma's reveal of being left-handed, Keith also switches to his dominant left hand having been using his right hand for most of the match.
Actually, this happens quite often, notable examples being in the manga.
During Kikumaru and Oishi's match against Rikkai's Niou and Yagyuu, it's revealed halfway through the match that Niou and Yagyuu have been imitating each other, and when they finally switched back to being themselves, their moves' power increase (helped by the fact that since Niou's dominant hand is his left, they've both been using their weaker hand up until the reveal).
Also with Shiraishi in the New Prince of Tennis, where it's revealed during a match that the reason his left hand was wrapped in bandages was because underneath he was wearing a golden gauntlet. With that taken off, the power and speed of his shots become impossibly high.
In chapter six of Zombie Powder, It is revealed that Gamma purposely handicaps himself when he fights against women and children. At the time, Gamma was fighting an old man with the appearance of a child, and when he realized this, he began to fight seriously. And beat the mickey out of his opponent.
Myojin pulls this in The Law of Ueki. Ueki thinks he's figured out how to beat him, then he reveals that unlike every other power user, he was given two special powers instead of just one.
Characters on Dragon Ball Z, whether hero or villain, tend to do this very frequently.
During the second Goku/Tien Shinhan match, both are about evenly matched until Goku stops and asks if he can take some of his clothes off. Tien obliges (it's apparently rather hot outside), and thinks nothing of it until Goku's undershirt lands on the floor with a heavy-sounding thud. Cue the weighted-clothing revelation and Tien's subsequent humiliation.
Having reluctantly teamed up with Goku to stop Raditz, Piccolo gets ready for the fight by taking off his cape, revealing that it's actually weighted training gear. Goku gets a kick out of this — and takes off his weighted clothing.
After taking a hard hit from second-form Freeza, Piccolo ditches his weighted cape and powers up to a higher level. This gives him the advantage until Freeza one-ups him by going to his third form.
Freeza is the franchise's absolute worst offender: One of our heroes finally has Freeza's measure? He just transforms to a stronger form.Three times. Later on, Goku is seemingly matching Freeza's strongest form - until Freeza reveals he's still not even using half his power. Goku assumes he's bluffing until Freeza goes up to 50% and starts kicking his ass all over again. Even after Goku turns Super Saiyan, Freeza has one more lengthy power-up sequence left as he goes all the way to 100%.
In Freeza's case, it's explained that he has difficulty controlling his true power and the transformations keep his power within manageable levels. This shows in Freeza rapidly burning out when he reaches 100% of his power.
Of course, at one point in the fight (after assuming his final form) Freeza intentionally gives himself a handicap, offering to fight Goku without using his hands, and he actually does for a while. He was likely just showing off, and stops doing it when Goku seems to be fighting better.
Played with in the fight between Gotenks and Super Buu. Piccolo assumes Gotenks really IS outmatched, panics, and traps them all in a pocket dimension. Gotenks then reveals that he was only pretending to be losing, and that he could secretly go Super Saiyan 3 all along. He was hiding it because he thought it would be moreBad Ass. He uses his withheld Super Saiyan 3 transformation to rip the fabric of space-time, escape said pocket dimension, and kick Super Buu's ass for five minutes anyway.
The tendency to fight this way gives Goku and Pan serious trouble against Haze Shenron. Pan has no problem kicking around this pathetically weak opponent but it turns out that his pollution aura has been sapping their strength, thereby giving him the upper hand. After escaping his area of influence and regaining their strength the pair are able to return and easily destroy him with an energy blast. They should have just done that in the first place.
In Gintama, Kagura pulls this on Abuto. They seemed a pretty equal match, until he has her pinned to the floor and helpless, but it turns out she wasn't fighting with her full power; she then goes full-on Yato on him and proceeds to give him a thorough thrashing.
Not a conscious reveal so much as a Superpower Evil Side triggered in response to Shinpachi almost being killed by Abuto. Shinpachi actually has to stop Kagura from killing Abuto, knowing that in her right mind she wouldn't want to.
In Gundam 00, Tieria is in control of Gundam Virtue, which is capable of transforming into the ridiculously powerful, androgynously-beautiful Gundam Nadleeh.
Debateable — Nadleeh is less capable of inflicting damage than Virtue and only slightly more manouverable; while it has the power to completely shut down certain opponents, it is less powerful than Virtue against all other foes.
In Yu-Gi-Oh! 5Ds Psychic duelist Akiza (Aki Izayoi in the original) has a hair braid that supposedly suppresses her powers (which is basically to make Duel Monsters and magic real); however, this may just be a Magic Feather.
Ryuho of Scryed, when, pressed by Kazuma, he reveals that his Alter, Zetsui, has a level of power previously unknown even to his closest allies.
It seems to be more of a justified power limiter as their energy is drained a lot faster when using it. Also his allies knew about it, but it was stated that it had not used for the last two years.
Gou from Getter Robo Go handicaps himself during a shot put event by only using his right hand. When he uses his left hand, he can throw the weight like a baseball.
Used almost literally in Mr Fullswing, where ace pitcher Inukai claims to have been a softball player for most of his time in middle school and throws underhanded pitches with his right hand... until the final batter of the tryout game comes up, and he switches to his natural left handed, baseball pitching style.
Similar to the Mr. Fullswing example above, the antagonistic billiards player Ryoji in Breakshot is narrowly defeated by main character Chinmi in a exhibition match, and it's immediately revealed that Ryoji, who had been using his right hand against Chinmi, is actually left handed and was going easy on him. When they meet again in the finals of the tournament, Ryoji reveals there's more to it than that; He actually let him win before.
Played straight, but humorously, in Hunter × Hunter, when the hero starts an arm-wrestling contest to earn money and only barely defeats an unassuming challenger who is later reminded by a comrade that they're not right-handed, she apparently has forgotten.
Played not so straight in the Greed Island arc, where Killua and Gon train with Biscuit Krüger who looks like their age, but isn't. Not only that but when she fights against an opponent while Killua and Gon aren't around, she turns into a huge muscley beast that is her "real form" and utterly obliterates the opposition. She's quite strong before this, so it isn't so much hiding her strength as it is she thinks the form is really ugly and doesn't want people to see it.
Played straight in Shamo, where Villain Protagonist Ryo Narushima spent most of all 5 rounds struggling to fight the heavyweight karate genius before a straight punch literally knocked some sense-inducing flashbacks into him, to which he switches to a southpaw stance, completely shocking the entire crowd.
It is also used as an explanation of why Ryo turned out the way he is. Yes, folks - he's evil 'cause he's left handed.
The entire Negi/Kotaro vs. Rakan/Kage fight in Mahou Sensei Negima!. The entire thing consists of the the opponents one-upping each other, to simply ludicrous levels. Negi does it five times in a single chapter.
Rakan later combines it with Screw Destiny. When disarmed, dislegged, told he's a puppet, and shown that the Princess has been hypnotized. He responds by putting on magical armor arms and legs and getting up for round 2.
You know what, just Rakan in general is this trope. After he was finally defeated by Fate and dissolved by the Code of the Lifemaker, he re-materializes when Fate taunts Negi and then gives Fate a final epic punch and tells Negi to kick his ass before dissolving for real.
Happens also in the final fight of the Mahora Festival Arc. After destroying the main secret weapon of his opponent (and his own equivalent weapon gets destroyed in the meantime as well), Negi declares that now he has an advantage because he can use magic and his opponent cannot. Then suddenly his opponent reveals that she is pretty good at using magic in battle too. Of course, he should have expected this, since she is his descendant from the future after all.
In an episode of Hikaru no Go, a guy named Dake-san is called in by the proprietor of a Go salon to teach a lesson to a kid who's been cheating. He pretends to be a weak player at first, among other things by holding the stones poorly - with his right hand. His moment is when he reveals that he IS left-handed.
Justified in Katekyo Hitman Reborn!. Ryohei only uses his left arm in his fight with Lussuria until he needs to. This is because he was saving the energy in his right arm so he could use his Maximum Canon.
"Haha, too bad. I've only shown eighty percent of my power so far." "I've only shown half."
In Angelic Layer, during Hikaru's fight with Shirahime, Shirahime takes off her kimono, increasing her already-amazing speed and turning the tide of the battle.
Eyeshield 21 football teams tend to do this by not allowing certain players to play until needed, as to make the enemy underestimate them.
In Fullmetal Alchemist while fighting Wrath, Scar reveals that during the three month break he has tattooed his right arm with his brother's reconstruction transmutation circle getting rid of his weakness that he could only deconstruct using alchemy.
Much earlier, Edward fought Slicer/Number 48 a Boxed Crook turned Animated Armor who displays his blood seal on the back of his helmet during the fight. Ed then knocks the head off, knowing he couldn't control a body he wasn't connected to, but then it turns out "Slicer" was actually twoSerial Killers (brothers), the other of which was put in the same armor, but the seal was on the torso. This is then Lampshaded after Ed beats him as well and he pokes the armor cautiously while asking if there was a third one. The older Slicer brother resignedly says no, it's just the two.
When Ed fights Kimblee, he manages to screw up one of the half transmutations circles on Kimblee's hands and knock the Philosopher's Stone out of his hand to prevent Kimblee from using any alchemy without wasting time drawing another circle, but Kimblee had another stone hidden in his mouth (and had for literally years). Explosions ensue.
Also, when Sloth gets badly pummeled by the Armstrong siblings, he remarks it's time to "go full throttle":
Sloth: "I am the fastest Homunculus."
In an extra chapter in the manga "The Military Festival" Ed and Mustang battle it out Mustang shoots flames at Ed as Ed runs around dodging. Ed suckers Mustang close enough to rip off the transmutation circle on his glove when Mustang reveals that his left hand (which was in his pocket the whole time) also has a transmuting glove on it. So it's more like I Am Not Right Handed. Later, during Mustang's fight with Envy, it tuns out to not be a gag when we see Mustang consistently using his left hand for pinpoint burning and his right hand for big explosions.
Parodied in Baka to Test to Shoukanjuu, when Akihisa goes up against Miho Satou, an A class student, Akihisa declares himself to be left-handed, but winds up losing anyway, because it's a fight determined by test scores.
In Chrono Crusade, Aion gets badly beaten by Duke Daffau when Daffau attacks Aion's base, Eden. For a moment, it looks like Aion's beaten within an inch of his life—until he reveals that he was holding back the entire time and proceeds start a trap that weakens Daffau and his troops, while activating a secret property in his sword that allows him to heal incredibly quickly.
In one of the Early rounds of the Do D tournament of History's Strongest Disciple Kenichi, Takeda claims he can handle an opponent by himself. Cue him getting whupped. He then states loudly that he's going to have to take this seriously, whereupon he takes off his shirt, revealing that he was wearing a full body spring retainer thing. This being a tournament where people have been known to die, everyone, including the announcer, declares him insane.
The Evangelions of Neon Genesis Evangelion have armor which doesn't protect them as much as it restrains them, even being referred to as "binders" when EVA-01 awakens after eating Zeruel. After defeating a particularly tough Angel, Unit-01 tears off its armor and scares NERV enough to put it under quarantine.
When the Evas go berserk, they tend to do things that didn't seem within their capabilities beforehand (regenerating arms, taking damage that would have destroyed them earlier, and in Rebuild, shooting lasers!).
Katanagatari has a particularly crazy example (warning: spoils an awesome twist). Despite being physically weak and ill, Nanami starts the series able to easily defeat her brother, who defeated the official Greatest Swordsman in Japan. Turns out, she can also copy any skill she sees, including super-strength, spontaneous claw growth, and walking on water. Then it turns out that she has inhuman resilience and can't die no matter how sick or poisoned she becomes. Then it turns out she's acquired one of the Deviant Blades, which cures her weakness and low energy. After all that, she still counts as Willfully Weak! She uses others' skills because her own instinctive combat skills are utterly perfect.
Also Shichika in the final episode, once he doesn't need to worry about breaking the Deviant Swords or getting hurt any more, unleashes his full power on the new wielders and effortlessly curb-stomps them.
Alice L. Malvin of Pumpkin Scissors pulls this bit in the final duel of the series when she switches hands mid-fight.
Star Driver episode 3 features a mecha sword fight. At first, Takuto's opponent is kicking his ass...until he pulls out a second sword. Eventually, we learn that Takuto has been doing this the entire time. What looks like New Powers as the Plot Demands is actually nothing of the sort. He's been trained to be a Driver since birth, and knew nearly everything his mech was capable of. Since he needed every advantage he could get, he fought his opponents using the minimum amount of skill and abilities, and whenever they reached the point where he was in trouble, he revealed his next trick.
And then comes another I Am Not Left-Handed moment after the fight itself: "How does it feel to use a cybercasket despite having a mark?"
In combat Lind of Ah! My Goddess wields a massive Lochaber axe against opponents. One such opponent, believing it to be her only method of attack due to not utilizing any other power, shattered it in an attempt to cripple her. A bystander snidely commented that the axe was Lind's way of being polite; commence massive kicking of bad guy butt.
She also pulled this on Hild in an earlier arc. The latter thought that she couldn't fight since she no longer had her angel, Lind ( and Keiichi's) reply can be summed up as I Am Not Single Angeled.
In chapter 240 of Fairy Tail, Ultear reveals that she can use Ice Maker Magic like her mother Ur when Gray finds a way to counter her Time Arc magic.
In the first Drama CD of Tiger & Bunny — set back in Kotetsu's high school days — Kotetsu gets into a match with Antonio (who has Nigh-Invulnerability as his NEXT power) and manages to fight him to a standstill... While entirely unpowered. When he ditches the fight to save someone trapped in a burning factory and activates his own NEXT abilities, Antonio is surprised to say the least.
Yaoi/baseball manga Perfect XXX. After pitching a few perfect games with his left hand, an opposing hitter actually hits a home run off of one of Kenshiro's pitches in the first inning, so the the next inning Kenshiro surprises everyone (well everyone on the other team and Ayato) by pitching with his right hand. Apparently the whole reason Kenshiro even used his left hand for everything (eating, writing, etc.) was to try to score points with Ayato, because Ayato said "Lefties are cool".
In Claymore, Teresa of the Faint Smile easily defeats the #2, #3, #4, and #5 without releasing any of her power. When the #2, Priscilla, unleashes 80% of her power and starts giving her trouble, Teresa simply releases 10% and easily defeats her again.
Gundam Wing has the reverse. During their duel where Wufei is struggling to match him, Trieze points out that Wufei could have torn him in half with his extendable dragon arms minutes ago and called it a day. Wufei says he wants to defeat Treize blade to blade (which is odd since Wufei is using a double ended spear at least twice as long as Trieze's sword giving him a massive reach advantage anyway). Trieze has to end up throwing the fight for Wufei to win, pissing Wufei off, and causing mental anguish that he didn't really beat him to haunt him for the next year.
In One Piece, during his battle with Blueno, Luffy realizes that he won't able to win as he's fighting currently, so he kicks in Second Gear.
Try to name one fight in Bleach where this doesn't happen. Every battle will have this (and/or Heroic Second Wind) occur at least once, if not multiple times. In fact, it's used so much that you can usually predict who will win a close fight based on who powers up first.
11th squad Captain Kenpachi used to braid bells into his hair so his opponents could hear him coming. By wearing an eyepatch over a fully functional eye not only impedes his vision but is composed of power-sucking creatures that keeps his power level down. He also insists on using his sword one-handed to weaken the force of his blows. When he does finally use his sword two-handed (and with his eyepatch removed), the power that explodes from his cut is enormous.
It's later revealed that even when Kenpachi stops holding back, he's actually still subconsciously holding back. He then goes through some Training from Hell to overcome that tendency.
Kenpachi's third seat, IkkakuMadarame likes to be straight-forward in battle. His skills, however, are anything but.
He employs a predictable routine of attacking with his sword in his right hand and parrying with his scabbard in his left. Then, just as his opponent has become comfortable with this style, he'll switch his sword and scabbard in mid-strike, reversing his attacks and parries and thus revealing he's ambidextrous.
His shikai manifests as a spear. Except it's not. It's really a three-section staff and it can slip between spear and staff at any stage, completely catching his opponents off guard and making his attacks unpredictable.
He greatest secret is that he also possesses bankai. He keeps this secret out of fear that he'd be forced to leave the 11th division and become a captain of another squad. He'll even throw a fight if he can't get away with using it in secret. Iba has hinted that Everybody Knew Already.
Yumichika's zanpakutou initially transforms into something that looks like a khopesh. Then he reveals it can actually transform into a four-bladed sickle-sword, although it doesn't do anything more than give his opponents very nasty wounds. Finally, Yumichika reveals this is actually a fake shikai and his real shikai is arguably one of the most powerful zanpakutou in the entire manga, being able to absorb the life energy from anything it captures and then use that absorbed energy to heal Yumichika's wounds. The only two times he's used it, he's one-shotted both opponents. The only reason he doesn't thrash people right and left with it is because it's a kidou-type zanpakutou which is taboo in the 11th squad. He'd therefore rather die than have his squad learn the truth.
Nnoitra's released form reveals four arms which even Kenpachi struggles to fight against. And then Nnoitra reveals he doesn't have four arms, after all. He has six.
Kyouraku subverts this. His shikai is a tricky set of weaponized children's games that trap both him and his opponent in the rules of the game until one or the other is dead. The three games his reveals become something of a pattern for him, one that Starrk gets used to. Then he reveals he had a fourth game all along, one that allows him to ambush strike through shadows. Subverted because Kyouraku actually doesn't choose to hide this power. His zanpakutou sets the rules and only lets him reveal his weaponized games when she's ready for them to be used.
When Uryuu and Mayuri fight, Mayuri believes he's resolved the fight quite quickly by paralysing Uryuu's body with poison. That's when Uryuu reveals he possesses a Quincy technique that allows him to fight normally even when his limbs are otherwise completely paralyzed. Uryuu later couldn't use this technique against Szayel because Szayel crushed his internal organs and any movements were making the damage worse. Using this technique would quite literally have been suicidal.
When fighting against Gatanbainne, Sado reveals the enormously powerful right arm he's been fighting with throughout the manga is actually a defensive, shielding power. His real attack force is located in his left arm and is much more powerful than his right arm's power.
When Soifon and Yoruichi fight, Soifon thinks she has the upper hand and proudly displays her ultimate technique which she's only just invented and mastered and hasn't even had time to name yet... then Yoruichi reveals that she knows all about the technique. She had developed, mastered, and named the technique decades ago and Soifon has in fact still got a long way to go before she comes even close to genuinely mastering the technique.
Gin Ichimaru's bankai extends his sword to 13 kilometers length, and he demonstrates its power by slicing buildings in half with one long circular swing. But he then reveals that the true strength of the weapon is not its length, but how fast it can extend and retract (roughly 500 times the speed of sound), essentially acting as a sword-shaped railgun/machine gun. And then, at a critical moment, he reveals that both of those are a lie. It's not quite that long and not quite that fast. The true danger in the blade is that when it extends and retracts, it dissolves into a metallic powder. A powder that when lodged in his enemies, can act as an exceedingly deadly, fast-acting, cell-destroying toxin.
When Ulquiorra and Ichigo have their final battle, the former finally decides the latter is strong enough to warrant activating his release, which he uses to completely curbstomp our hero. Then, when Ichigo refuses to give up despite the clear power gap, he decides to show him his greatest secret: He has not one, but two releases, and is the only Arrancar to ever succeed in doing so. He then proceeds to open an even greater can of whoopass on Ichigo, and even goes so far as to be perhaps the only villain in the manga so far to actually kill the hero (however briefly).
DC Comics icon Superman is prominently known for holding back all the time to avoid one-shotting his opponents' heads off as well as general collateral damage. When the gloves are off, however, fights tend to end quickly. Issue 669 explores this in depth (a flashback to his rookie years, when he had to be extra careful because humans are squishy). For what happens when Superman stops holding back, see "World of Cardboard" Speech.
In Final Crisis, Superman builds The Miracle Machine, which can grant one wish. Mandrakk arrives and says he did that for nothing, as he has no power source great enough to activate it. Superman unleashes the stored yellow sunlight within his own body, turning it on. He wishes for... a happy ending. This simply ensures that the good guys will win this battle.
Likewise, Mr. Tawky Tawny is involved in this crisis and the Tigerman leader he fights - Kalibak, the son of Darkseid - learns the hard way that while he may look like a wimp in his tweed business suit and bowtie, he is still a mighty tiger!
Competitor Marvel's flagship character Spider-Man does something similar to Superman, too, albeit at a much lower level; after all, Spidey collars ordinary crooks almost as often as he clashes with super-villains, and using his full strength to punch out a non-superpowered bank robber would end up rather messy. Often, he avoids this simply by webbing up normal guys rather than fighting them directly.
In the "What If?" Civil War special, Henry Gyrich creates an army of Thor clones to enforce registration. Reed Richards notes that Thor once told him that no matter how powerful a mortal is, he will only ever use a third of his strength for fear of killing them. The clones, of course, have no such restraint.
When the real Thor comes back after Civil War, he confronts Tony Stark over what he did - with his hammer. When the lightning bolts start flying, Tony blasts him - to no effect. He tries the "old school" approach, and Thor sends him flying and near-cripples his armor with one hit. He says that Thor must have been working out, in shock at how hard he was hit. Thor replies that the only difference this time is that he isn't holding back.
Cyndablock also does this earlier, when he and Emp were getting thoroughly thrashed by a villain, he shows that he has the ability to manipulate concrete, masonry and pavement, but doesn't use it much because it could cause a lot of collateral damage and the aftereffects tend to linger.
Near the end run of Birds of Prey, the team moves their headquarters from Metropolis to Platinum Flats, which just happens to be the next town over from where former member Black Canary is now living. Of course, it ultimately results in a Let's You and Him Fight between Black Canary and current Bird of Prey member Manhunter. As they battle Manhunter prattles about her recent fights against other superheroes, explaining the successes she has had in sparring matches against the likes of Wonder Woman, and is happy to finally have a chance to see how she compares against such a famed martial artist as the Canary. However, a while into the fight she questions the Canary as to why she has not used her signature Canary Cry, to which the Canary responds that she "is trying really hard not to put [the Manhunter] in the hospital."
In the Flash: Rebirth series, Superman is chasing after Barry Allen, when Superman begins talking about the races they've done in the past. Barry responds with "Those were for charity, Clark," and immediately speeds off, leaving Superman dumbfounded and far, far behind.
This is a retcon. Superman's speed used to be a match for Barry's but it had been retconned to be slower in the 25 years since their last race.
X-Men - Cyclops's glasses / goggles don't just let him control his powers, they also limit them. If he's willing to take his visor off for even a few seconds, you're in trouble.
Another instance of this is in the first volume of Ultimate X-Men. Cyclops is being restrained by a Sentinel because it has figured out that he operates his optic blasts by pressing a button on the side of his visor. Scott then reveals that he can also do it by snapping his fingers.
One issue of The Mighty Thor had Hercules telling a tall tale about a fight with Thor. He was just getting to the point in his story of beating the daylights out of the thunder god when he learned that one of the young listeners was a serious Thor fan. So Hercules abruptly changed the ending to reveal that Thor had been holding back all along, and "He flung me into a land the gods forgot: New Jersey!"
The last fight in Doctor Strange: The Oath is a fistfight between Strange and Nicodemus West, who also knows magic but has deployed some anti-magic phlebotinum, expecting he can take Strange in a fair fight. Doc lets West pummel him for a minute or two (and waste his energy) before breaking out the Kung-Fu Wizard skills.
In one Garfield strip, Garfield harasses a leashed dog.
Sigurd: ...I've got a confession to make. I'm actually left-handed. *switches his sword to the other hand*
Loki: Oh? Then I, too, have a confession to make— *switches HIS sword to the other hand* I've seen that same movieeep!
Sigurd slices off a little of Loki's hair and kicks him out of a window.
Sigurd: Ha! Made you look—
In the Harry Potter fanfic "Burnt", Harry used his crippled appearance to his full advantage when he was on the street, and a bit when he's at Hogwarts. He is more than capable of defending himself and could take on any student in his year.
The trope name and the page quote come from The Princess Bride. Inigo Montoya is so good that he fights with his left hand just to keep things somewhat challenging, but when faced with the Man in Black, he realises he's being outmatched, and switches the sword back to his right hand to gain the upper hand again. Too bad the Man in Black was also fighting with his off-hand, presumably for the same reason.If you look closely, you'll notice when the Man in Black first starts to draw his sword, he is drawing it with his right hand until he notices that Inigo plans to fight with his left-hand.
There is an old live action kung fu movie which uses this Trope. One villain, who has chicken in his fake mustache and calls the hero a cur, initially wields a gigantic Cloud-esque sword. Eventually, this weapon tires him, and he pulls the hilt of the weapon out of the blade, revealing a tiny blade attached to the removed hilt which he uses much more effectively.
Zatoichi (the 2003 film) subverts this: as he is killing the last two Yakuza members, Zatōichi opens his eyes and the Yakuza boss assumed he could really see. In the very last scene of the movie, he trips over a rock and a voice over says "Even with my eyes open, I still can't see a thing."
Subverted in the Rocky series. Neither Rocky nor Stallone are left-handed, but throughout the movies he fights south-paw by preference. In fact, a substantial part of his training for the rematch against Apollo Creed in Rocky II centered on Rocky learning to fight right-handed, and switching to using his left at a crucial point in the fight to devastating effect. Rocky "is not left-handed", but unlike these other examples he is a distinctly superior fighter when favoring his off-hand.
The movie I, Robot features a fight between Will Smith's character, Del Spooner, and an NS-5 robot that's actually trying to kill him (as opposed to the fight with Sonny, earlier in the movie). Spooner hits the robot with a metal pipe once or twice, which the robot shrugs off, and it acquires possession of the weapon. After successfully dodging the robot's first swing, the robot's second and third swings are blocked by Spooner's left arm - and on the second impact, we see part of the inside of the arm exposed, revealing that Spooner's left arm is, in fact, mechanical. (Which - when the robot looks surprised, or as surprised as a robot can be - he acknowledges with an almost-apologetic "Yeah.") He connects with a hard punch and a leg sweep using that arm, and tries to punch the robot while it's on the ground - only to miss, and have his fist go through the asphalt.
Lt. Col. Alan Caldwell: Now, are you sure you want to have a fight? Because I'm only gonna use my thumb.
Bully in Bar: Thumb?
Lt. Col. Alan Caldwell: My right thumb. Left one's much too powerful for you.
In Beerfest, the heroes pretend to be more drunk than they really are to trick the Germans into making a steep bet. Todd, however, really is that drunk, having been forced to use his "drunken recall" earlier.
In A League of Their Own, the "ugly" girl, Marla Hooch, has a moment like this during her batting demonstration for Ernie Capadino (Jon Lovitz). After several good hits, Marla's father says, "Okay, Marla, now hit lefty," which causes all the guys in the field to groan in anticipation. She had been batting right-handed, but was a switch-hitting natural left-hander. She hits a towering home run, and gets signed for the new league.
A variation of this takes place in Die Hard. Gruber has John McClane at his mercy, unarmed and shirtless, with no obvious place to hide a gun. As the camera pans behind McClane, we see that he had taped a gun to his back.
In TRON: Legacy, Sam fights his way to where his father's identity disc is being held. He gets cornered by Rinzler escorting a captive Quorra, who had previously trounced Sam using dualdisc weapons. Rinzler doesn't account for the fact that Sam has two disks on his person now too when he and Sam square off. The surprise second disk careening at his head, combined with Quorra using that as a distraction to kickbox him (as her hands were bound), is too much for even Rinzler, and he's left hanging... literally.
In Uncommon Valor, Scott has finally had enough of the much larger Sailor and says he thinks he can teach "an undisciplined brawler" like Sailor a lesson. The huge, lumbering Sailor rushes Scott a few times only to be knocked on his butt by Scott's martial arts skills. Tiring of this, Sailor says to Scott, "Usin' that Oriental martial bullshit on me's gonna get real expensive," assumes a real fighting stance, and uses his own kung fu skill, which turns out to be superior to Scott's, to treat Scott to "the whole can of whoop-ass."
A variation occurs in The Quick and the Dead. Ace Hanlon, the big bloater, claims to have two good shooting hands. In his match against Herod, first it turns out that at least some(probably all) of his war stories were fake, and Herod proceeds to shoot Ace in his right hand. Herod offers to take the next shot with his left hand, because unlike Ace, Herod really can aim well with both hands. Naturally, this story doesn't end well for Ace.
In Back To The Future Part III, a gun salesman is trying to teach Marty how to shoot, to demonstrate the Colt Peacemaker, and laughs at Marty's terrible shot. However, turns out Marty is not left handed, he switches to his good hand...
It might be worth noting that the salesman seems to deliberately thrust the gun into Marty's left hand. Marty does try to switch hands, but the salesman stops him. So the whole thing could be seen as the salesman deliberately trying to make him look bad.
As noted on other pages concerning this, revolvers were shot in the left hand during those days. This was because you needed your right hand to hold the reins of the horse.
Occurs twice in the Marvel Cinematic Universe, when Thor is fighting Loki. Thor is initially holding back, not wanting to hurt his little brother, but then Loki pushes him too far. Both times Thor stops holding back, and promptly defeats Loki.
In Thor, Loki actually does this on purpose wanting Thor to fight at full force. He makes a comment about "paying Jane a visit" to enrage Thor. Which didn't work out for him.
In The Avengers Thor is desperately trying a Get a Hold of Yourself, Man! to Loki. He seems to consider it, and then stabs Thor sneering at the "sentiment." Thor promptly grabs Loki, lifts him into the air, before slamming him onto the ground. Director Joss Whedon even described this point as Thor "finally having enough of Loki's shit."
In This Book is Not Good For You from the Secret Series bynP. Bosch, Seńor Hugo goes along as a blind man but eventually reveals he still has one good eye.
Starfighters of Adumar has a scene where Wes Janson faces a foe in a sword fight, and uses his weapon in his left hand. This is actually a feint, as he immediately uses his free right hand to disarm his overconfident opponent. After that the fight becomes a brutal display of how his extremely skilled opponent never bothered to train for situations where he would not actually have a weapon.
In Drew Karpyshyn's Darth Bane: Path of Destruction, Bane eventually has to fight Kas'im, the Blademaster from the Sith Lord academy where he had trained, who uses a two-bladed lightsaber. Though Kas'im is the foremost Master Swordsman of the Sith, Bane is stronger in the Force and, after training with Kas'im privately for countless hours, already knows all his moves. The pupil is at first beating the master... until Kas'im detaches his saber-staff into two separate sabers, revealing that the real reason he has been telling his students Dual Wielding is useless is so that no-one else would learn it, or how to defend against it, which Bane indeed now can't.
In the novelization of Revenge of the Sith, Count Dooku is disappointed at how easily he's defeating Obi-Wan and Anakin, until it is revealed that they have been disguising their favored fighting styles by using lightsaber forms they are unfamiliar with.
Iorek Byrnison pulls one of these in his fight against Iofur Raknison during The Golden Compass by pretending his left arm is too badly hurt to be used in the fight.
Daniel in The Dangerous Days of Daniel X by James Patterson. It's not that he discovers a new power, but more like he discovers a new combination of attacks to defeat the villain.
Cats Have No Lord by Will Shetterly deliberately echoes the The Princess Bride trope, up until the "I'm not left-handed either," which is not true, but a ruse to distract the opponent so that sand can be thrown in his eyes.
Happens literally in the second installment of the Toldi Trilogy, written by János Arany. The titular hero participates in a tournament for the sake of fighting, but is not interested in claiming the prize (marrying the daughter of the host), so he agrees with a left-handed knight (who is in love with the girl in question) to impersonate him. During the final duel, he almost gives himself away when he switches hands, because he can't handle his opponent while holding the sword in his left hand. The trope is inverted when he's eventually challenged by the same left handed knight he impersonated, over a matter of honor and Toldi is unable to get an edge over him, because he's not used to fighting left handed opponents. He eventually defeats his rival using his left hand.
Brian Daley's The Starfollowers of Coramonde has a character named Brodur who uses his right hand in fencing while setting up a hustle bet, and insults his opponent by saying, more or less, "I could beat you, even left-handed." Brodur is left-handed, and once the bet is for big money, he shows it.
In the fifth Skulduggery Pleasant book (Mortal Coil), Skulduggery and China corner an expert swordsman by the name of Burgundy Dalrymple and ask him to surrender. He appears to be thoroughly beaten and remarks on how the heroes seem to have bested him when he suddenly swaps his sword to his left hand and proclaims, "I am not right handed!"
the exchange leading up to that moment is an almost word for word parody of the Princess Bride.
The Royal Manticoran Navy of the Honor Harrington series required their newly-built pod-laying Superdreadnoughts to do this in the run up to their all-out offensive, in order to conceal the existence of the ship type and their revolutionary abilities from the enemy. The result was SD(P)'s performing at a fraction of their capability...and still annihilating enemy squadrons all by themselves.
War Of Honorshows what happens when you reveal this too early: The Manticorans are forced back onto their heels by the Havenites unexpectedly pulling this, thanks to Admiral Shannon Foraker being a very busy girl during the Cease Fire. They reveal some devastatingly powerful new superweapons, but they are not ready to deploy them to the entire fleet yet. Realizing this, the Havenites send what is, at that point, the largest battle fleet in history in an all-or-nothing bid to crush the Manticoran homeworlds' defenses and force a surrender. They fail, but not before over a million people on both side die in the battle.
This was also policy later when they found themselves in skirmishes against the Solarian League, to run the starship impeller drives at lower acceleration and fire from ranges that would only need two drives of their Multi-Drive Missiles rather than the range offered by the full three. This was, in significant part, to prevent the much larger Solarian League from realizing how badly outmatched they were in case the Manticorans couldn't prevent an all out war.
Unfortunately for the Manticorans, this was also the case for the Mesan Alignment Navy, who managed to conceal their entire existence behind the front of the comically inept and corrupt Mesan Navy. Their first move against the Manties? OysterBay.
Although this was one-off surprise attack (described as a trick only best duelists could pull off), good against average opponent but not so useful against the professional knowing all tricks of the trade.
Jaime Lannister averts this trope in A Song of Ice and Fire in the most heartbreaking way after the Bloody Mummers cut off his right hand. He tells people jokingly that he only let them do it because he wanted to make swordfighting more interesting. In reality, however, he's not remotely competent with his left hand - he can't even hit a bear with a thrown bone.
At the beginning of Knife of Dreams in the Wheel of Time series, Galad deliberately holds back for most of his fight with Eamon Valda, attacking and parrying a bit more slowly than he could have. Then, at the end of the fight, he goes all out.
Alanna does this in the second book of Song of the Lioness. She's chosen to duel for Tortall's honor when a knight from Tusaine's delegation insults them; when he wound her in the right arm and presses for the kill, she switches her sword to her left hand and defeats him. This is a Chekhov's Skill from the first book, when she was shown learning to fight left-handed after breaking her right.
In Entourage, Ari attempts to trick a studio executive into betting Vince into a movie during a golf game - he purposefully loses the first nine holes before making the bet, and then his game miraculously improves. The exec accuses Ari of trying to trick him - then reveals that he plays much better left-handed, and goes on to defeat Ari.
Angel does this on a regular basis, usually revealing that he's a vampire about halfway through the fight. Vampires, for example, do not breathe, which Angel noted way back in Buffy when a character needed mouth-to-mouth.
"Right now I'm crushing your windpipe."
"Guess what I'm doing now? Not using my windpipe."
Jack Deveraux does this while fencing Lawrence Alamain in Days of Our Lives. Rather than reveal he's not right-handed during the fight, he waits until he's already defeated Alamain, to twist the knife in even more.
In the Doctor Who episode "The Christmas Invasion", the bad guy has the Doctor at a disadvantage in their challenge sword duel, and slices off his right hand. The Doctor, however, grows a new one instantly due to previously-unknown Applied Phlebotinum, dubs it a 'fightin' hand', and proceeds to soundly defeat the bad guy.
In Band of Brothers this trope appears in such perfect form it almost looks like it was the Trope Namer. In the 4th episode ("Replacements"), Buck Compton plays darts against one of the new guys—Heffron—and loses saying, "It's a good thing we weren't gambling." Heffron suggests they bet on the next game and Buck "reluctantly" agrees. Before Buck takes his shot, he switches to his right hand and wins easily. Heffron has just enough time to realize he's been conned.
George Luz: Lieutenant, are you going to shoot lefty all night?
Joe Toye: Hey, c'mon.
George Luz: I'm just curious cause he's right-handed.
'Buck' Compton: [switches hands] George, what would I do without George Luz?
In an episode of the MADtv recurring skit "Average Asian", a man challenges said Asian to a game of ping pong. After losing, the Asian says "Let me put the paddle in my OTHER hand" needless to say, "He's an expert Asian! When it comes to ping pong!"
This was also an homage/send-up of a similar scene from Danny Kaye's The Court Jester, where Kaye goes from stumblebum to master swordsman with the sound of a finger-snap while fighting Basil Rathbone.
Zorro: In the 1957 Disney TV series, Don Diego de la Vega is a master swordsman, with many awards for his swordplay in Spain. When he decides to become a sword-fighting vigilante, one of the first things he does is to dispose of his awards so as to better pass himself off as a clumsy Idle Rich to his new neighbors in California. One episode's plot naturally revolves around Don Diego being challenged to a duel, and having to somehow win while still fighting left-handed (figuratively speaking) so as to avoid blowing his cover.
Everybody Loves Raymond: After Ray loses a ping-pong match with his father, his father reminds him that "it's a good thing he wasn't using his good hand" and switches his paddle to the other hand.
Buffy the Vampire Slayer, "The Freshman". A vampire has busted Buffy's left arm up, and she's spent most of the episode conspicuously not using it and fighting one-handed. Then...
Buffy: When you look back at this, in the three seconds it'll take you to turn to dust, I think you'll find the mistake was touching my stuff. Sunday: What about breaking your arm? How'd that feel? Buffy:Let me answer that with a head butt. And for the record... The arm is hurt, not broken. *Punches Sunday halfway across the room with her left hand*
Later at the end of Season 4, Buffy manages to break the skewer (which had been Adam's primary weapon). Her triumph is short lived. Bonus points for the skewer coming out of Adam's left arm.
Buffy: Broke your arm.
Adam: Got another. (His right arm turns into a gatling gun. Cue an Oh Crap look from Buffy.) I've been upgrading.
Joss Whedon scores a hat trick here; in the pilot of Firefly, the titular vessel Serenity is fleeing a Reavers vessel hot on her heels and bearing down upon her - turns out that her thrusters rotate all the way round, allowing her to pull a Crazy Ivan and escape.
Wash: Here's something you can't do.
In Spin City, it is a rule that when you play racquetball against the mayor, you lose (intentionally). But then Charley is stressed out because of his work and the mayor taunts him one too many times. Charley switches his racket from his left to his right and gruesomely beats the mayor.
In Noob, Gaea is a notable hoarder of both money and precious items and a Dirty Coward when it come to combat. However, if she's conered into combat and has her mind set on winning, she does NOT consider her most powerful items to be Too Awesome To Use.
In many shooting videogames, players are often limited to usually using a pistol or shotgun, due to lack of ammo for more powerful weapons. This often leads to them saving the BFG for Demonic Spiders or That One Boss.
Which is usually built into the game's expected strategy. A good example is Time Crisis 3. The first stage gives you a grenade launcher with two rounds near the end. Genre Savvy players will save it where the final boss, a giant tank turret, can be eliminated with just those two rounds. Less savvy players will use them in the trenches to clear out corners filled with enemies and have only the pistol left for the boss.
Same with Role Playing Games, where players will just keep on using regular attacks on the regular mooks they encounter to save up items and MP, only to open the whole can of whoop-ass on stronger enemies.
Played with in Super Robot Wars. Sanger Zonvolt is best known for piloting a mech whose only weapon is the Type-3 Zankantou and which uses a custom operating system that turns it into a Motion Capture Mecha. In OG Gaiden, a villain tries to take advantage of this by disabling the Zankantou, only for Sanger to switch back to the default OS and kick his ass with the onboard weapon systems. The catch is that these weapons had never made any kind of in-game appearance before and had only been referred to via concept art in the artbooks for SRW Alpha 2 (where Daizengar made its first appearance). So it's less "I Am Not Left Handed" and more "I AM Left Handed, But I Can Kick Your Ass With My Right Hand Too".
Nero does a form of this in his fight with Dante in Devil May Cry 4: he's been keeping his Devil Bringer hidden under the pretense that his arm is broken and he must carry it in a sling. He fights Dante for the majority of their first contact with his right arm hidden in the sling, and just when Dante has the upper hand and is about to run Nero through, he suddenly throws the sling off and blocks Dante's sword with his cursed arm, stopping Dante in his tracks.
Vergil also does this in 3. In the first fight against him he stays in human form all the while. By the second fight he pulls out the Devil Trigger after you damage him enough. In the third and final fight, he gets to use an even more powerful Super Mode on top of the previous one with deadly Secret A.I. Moves.
It should be noted about the Devil Trigger, that before 3 it is played up like Dante has never been able to access it, so after Vergil kicks his ass in a cutscene after the bossfight that it awakens Dante's own abilities. Sort of giving Dante his own "I Am Not Left Handed". In fact in all the games save for 2 and 4 Devil Trigger isn't attained until a certain point so it's always been a hidden Super Mode technically.
In the first game, the default sword Force Edge is it's own "I Am Not Left Handed", in the fact it doesn't have a Devil Trigger form for Dante, and not until the right moment releases it's true power to become the sword Sparda, which let's Dante Devil Trigger into his father's Demon Form.
Some time after his death in Fire Emblem 9/10, Greil is revealed to have crippled his sword arm because Lehran's medallion caused him to go Axe Crazy and kill his wife. When the Black Knight finds out he didn't fight the true Greil because of this, he holds back in his final fight in PoR so that Ike will become stronger and show him what Greil was truly capable of.
And the person that reveals this to the player also counts. Volke is actually an assassin hired by Greil to kill him just in case he goes berserk again. After the revelation Volke gets his promotion from thief to assassin. And then makes the same deal with Ike.
Subverted by Boris. He seems to legitimately be left-handed, given from how he holds his rifle. It also appears to be a left-handed variant (given where the ejection port is).
In Talesof Symphonia Regal Bryant fights only using kicks, keeping his hands shackled. Late in the game, you find out firsthand that when he fought using his hands, he was as or more powerful then, than the team is currently, and that was without the Exspheres that allow them to be powerful.
Joshua of The World Ends with You at first appears to be a Pretty Boy who fights with a psychic cell phone. He can't jump, and his ground combos only deal damage after the last button is pressed (Shiki and Beat can deal damage with every press). However, when Joshua and Neku are confronted by a Taboo Noise, and all hope seems lost, Joshua suddenly reveals he can levitate and proceeds to vaporize the Noise with a Jesus Beam. Afterwards, the reaper, Koki Kariya, confronts Joshua and notes that such power can only come from someone who is still alive while playing the game, and he tells Joshua that he will let it pass as long as Joshua doesn't pull the same stunt again, because the reapers themselves were having trouble with the Taboo Noise. He later goes all the way up to A God Am I when he reveals that he is Shibuya's Composer, The Man Behind the Man.
Chrono Trigger: Slash, one of Magus' generals, is as famed as a legendary swordsman as his comrades are for their control over magic. When confronted, he puts up a respectable fight, but something just seems to be missing... until halfway through, when he acknowledges the team's prowess and takes his sword off the wall. Uh-oh.
Slash: You're more powerful than I thought! I better use all of my strength as well. [pulls sword off of wall] And you, without Cyrus... [unsheathes sword in slashing motion]You've no hope!
Some gamers still have a soft spot for his old battle cry. "Yes, indeed!" heralded pain.
In Guild Wars, one of the NPC henchmen, Lukas, will occasionally shout "I am not right handed!" as one of his combat dialog lines. (he wields his sword in his right hand, of course)
Ace Combat X: Skies of Deception has the mission Time Limit, where an unstable neutralising agent forces Gryphus One to fly slowly and with reduced maneuvering. Two Leasath pilots proceed to trash talk about how he's not what the rumours make him out to be and stalk him in this near-defenceless state. When Gryphus One finally gets to discard the neutralising agent and dogfight properly, the two are taken aback by his real prowess and don't last long.
Akuma from Street Fighter does this deliberately. The form everybody sees him in is Akuma using only part of his power. Shin Akuma, however, is when Akuma stops holding back and goes full-force at whomever he's fighting. Considering every version of this form that a player can fight doubles as an SNK Boss, it's lucky he doesn't do it more often.
Oro from the Street Fighter III series keeps his arm binded in his gi sleeve so he doesn't accidentally kill his opponents. He gets to use both his arms in powered-up versions of his supers in Third Strike.
Applies to Cody as well, who intentionally wears his handcuffs for this very reason.
Which is an idea that was first implemented in Sonic X where he removes the ring to better use the Chaos Emerald's powers, though weakening him in the process. This is noted mainly during the final battle of the Sonic Adventure 2Story Arc of the show when he goes Super with Sonic and stops the ARK from falling on Earth by removing the rings again to give him enough juice.
Sonic himself pulls this in Sonic Battle as well as a Let's Get Dangerous, when he has to fight Emerl. Surprisingly, this is one of the few (if not the only) instances of Sonic not playing around with his opponent or in general. He goes from an adrenaline-pumped and cocky Kid Hero to (disturbingly) a deathly serious and utterly Pragmatic Hero. Then again, when you have 30 seconds on the clock (the previous 30 seconds spent trying to negate the Chaos Emeralds with the Master Emerald and FAILING) before the Final Boss (who happens to be a Physical God) blows your home planet to nothing with A STAR SYSTEM BUSTER and the only way to do stop them is to KILL them (and it's someone you really care about) why would he play around? Sonic just proved why he is the fastest hedgehog alive and that he's got some serious brass ones. He's been holding back a lot more than what we believed he did.
Ragna the Bloodedge from BlazBlue holds great power in the Azure Grimoire copy/fake that makes up his right arm, but refuses to use it for much of the game. When he does, stuff starts hitting the fan very quickly.
Big Bad Hazama/Terumi does this too as he created the Azure Grimoire.
Zeno Clash's second Hunter battle begins with the titular boss keeping one hand behind his back as he fights you. (This is in addition to the fact that he's blind.) Whittle his health down enough and he brings both arms into play - and beats the living hell out of you.
In a cutscene in the Final Fantasy VII prequel Crisis Core, Sephiroth and his then-friends Genesis and Angeal are having a 'play fight' on the Junon Cannon. However, when Genesis gets carried away and goes overboard, Sephiroth reveals just how much he was holding back earlier. Cue Curb-Stomp Battle, complete with kickass version of One-Winged Angel. Even better, Word of God says he still hasn't been seen at his full power. Also played upon, as he is using his right hand in most scenes, but he is actually LEFT HANDED.
World of Warcraft: The Lich King manages to pull this in the final fight in Wrath, when he stops messing around and slays your entire party with one attack.
Resident Evil 4 often requires this to be able to survive the tougher enemies. One can buy a rocket launcher and make quick work of what was originally to be a boss that could easily kill you. The fully upgraded Broken Butterfly will also get the job done.
El Gigantes are most notable examples. Instead of having to shoot them multiple times, then attack their parasites, you just need to shoot them once with a rocket.
Shoot Salazar's "Right Hand" with the upgraded Broken Butterfly or a rocket launcher after freezing it the first time and it will shatter.
The Fallout games allow you to specialise in many different weapon types. You can be really good at using ordinary ballistic firearms but choose to use energy weapons even if your skill with them is weaker but you like the pewpew effects. But when it comes down to fighting a particularly tough enemy, you can always put the laser rifle away and switch to a high-powered Anti-Materiel rifle with explosive ammunition and turn a deathclaw into bloody chunks.
Unfortunately your NPC companions In Fallout 3 and New Vegas are never left handed and will nearly always use the biggest weapon you have given them. Players using their companions as pack mules must take care to never give one both the weapon and the ammunition to carry at the same time, lest they find their sidekick firing your carefully hoarded and expensive missiles against molerats.
Fallout New Vegas when playing with the GRA DLC installed active encourages the player to be left handed. Part of this DLC adds a series of Challenges that often require the player to kill thing very powerful (ie five Deathclaws) with one of the smallest weapons in the game (ie a .22 pistol). While the savy player will realise that to count as a formal kill only the last HP needs to be removed with the required weapon, and hence soften up the target with something more sensible first, most of these Challenges are still excellent ways to discover when the player last made an autosave.
In Jedi Academy it's possible to switch lightsaber styles(there's five in the game, depending on your choice in lightsaber you can get at most three of them), and Kyle even recommends you do it for this trope's sake. The extreme effectiveness of doing this was carried over from the previous game, Jedi Outcast. The Strong style is actually only useful for this in lightsaber fights, ending a battle or knocking the enemy's lightsaber out of their hands (or both).
In Asura's Wrath, half-way through the fight with Augus, he relishes the fact that Asura is putting up a decent challenge and takes out his sword Wailing Dark, proclaiming that not even the finest wine or the fairest maiden excites him as much as using his blade. The game then cuts to Yasha and Deus, who senses this and notes that Augus has only ever used his sword once before, and that was with Deus himself.
In Sharin No Kuni when Kenichi fights Houzuki, he finds out that Houzuki's leg is actually completely fine, and promptly loses the fight as a result.
The God of High School: Jin Mo-Ri's power level is estimated at level six when he first enters the tournament. That is, until he actually uses his legs to attack, which more than doubles his power level to 13. Furthermore, the judges revealed to be holding back by not using their special abilities.
In the final showdown between Captain S and the Game Genie, Captain S seems to have the Genie's number before the Genie proclaimed "We're not * snort* left-handed." and proceeded to transform into his true form
After failing to do any damage to Malachite in Suburban Knights using their costumed weapons (which makes sense since they were mostly just props) everyone abandons their "characters" (Lupa stops acting princessy, Linkara starts using his magic gun, Angry Joe gets out his weapon arsenal etc.) It still doesn't work though since Malachite is a dark mage while everyone else are mostly unpowered nerds.
On the subject of Linkara's magic gun AKA Margaret, she has been holding back her full strength most of the time. There are a couple sneak peaks of it in the "Silent Hill: Dead/Alive" and "Silent Hill: The Grinning Man]] reviews, but we don't really properly see the gun cut loose until Star Wars 3D #1.
A textbook example happens in the My Little Pony: Friendship Is Magic fanfic Rainbooms and Royalty when Twilight tries to stop Blackened Armor (her brother who's been corrupted by Nightmare Moon). He mocks her, saying that he remembers everything from his old self and knows that he always won whenever they duelled in the past. Unfortunately for him, he doesn't know that Twilight has been holding back ever since the traumatic day she gained her cutie mark and her power awakened, deliberately keeping her strength down for fear of hurting others. He also doesn't know that she's recently been having an inspirational talk with Rainbow Dash and Applejack, convincing her to trust her magic power and not fear it. She even cites Superman's "world of cardboard speech" before letting loose on the villain.
In Doug, Doug is playing baseball but plays horrible until Patty notices he favors his left hand and realizes he's a lefty. Once Doug swings left-handed, he actually plays competently. This is ironically the opposite of the name of this article.
Avatar: The Last Airbender: Zuko does this when fighting an earthbender and realizing that holding back his firebending to conceal his identity is no longer an option.
This backfires on him, when the very people he was protecting and risking his life for, treat him like dirt afterwards and run him out of town, albeit understandably, seeing as Zuko's father is leading the army that's been oppressing them and aside from his one stray good deed they've only ever been mistreated by the Fire Nation before.
Grojband quotes this trope almost word for word when Corey dukes it out with a pirate captain in "The Pirate Lounge For Me".
The moment when Flash surpasses any speed ever achieved by a human being in order to whup Brainiac-Luthor's ass in the Justice League Unlimited episode "Divided We Fall". The episode practically gave the character an immediate boost from the goofy, comic relief of the League to an absolute badass in a few seconds. And to show how serious he was, we learn that going that deep into the Speed Force runs the risk of not coming back.
At various times it is made very clear that The Flash, much like Superman, can cause a lot of collateral damage if he isn't careful. As for the above example, it's implied that he was approaching the speed of light and you can see cars flipping and distant windows shattering just from how fast he is moving. He outright doesn't use his ability to phase through solid material, because it can cause explosions or instant destruction.
Also in Justice League, Superman lets himself get beaten up a lot because of this; he will fight using all of his powers; indeed, and he's beaten many times, but either because somebody broke out the kryptonite or because he's holding back early on and for some reason can't go back to being right handed. Case in point: when he unknowingly fought Wonder Woman, he had to stop fighting period once he realized it was her, and got badly beaten up because of that. However, he frequently talks about the reasons he does this. At one point, he says that every hit he takes is one less hit his teammates has to. This especially comes to proof when Superman fights Darkseid in the series finale. After getting beat down, Superman gives his famous "World of Cardboard" Speech:
I feel like I live in a world made of cardboard. Always taking constant care not to break something, to break someone. Never allowing myself to lose control even for a moment, or someone could DIE. But you can take it, can'tcha, big man? What we have here is a rare opportunity for me to cut loose and show you just how powerful I really am.
He then turns the tables and lets loose on Darkseid, knowing that he won't be killed right off, and easily kicks Darkseid's ass, sending him flying through several buildings to the other side of the city and then bashing him back down to the ground. Unfortunately, Darkseid then does this as well. Realizing he's outmatched physically, then switches to his technological superiority and instantly defeats Superman.
General Grievous at the end of Star Wars: Clone Wars. You thought he was tough with two arms? Well, now he has four.
The Simpsons: Marge Simpson, of all people, invokes this trope literally in the recent Vancouver Olympics episode. Her arm is sprained in the second-last match, and is about to give up. Then, Homer notices her skill with her other arm, which Marge remembers is actually her dominant one.
Rafael Nadal (an 11-time Grand Slam Champion) is right-handed, but he learned to play left-handed for purely strategic reasons; there are not too many lefties in tennis so opponents can find it difficult to adjust to playing against. In particular, it has helped him become the only player in the world to consistently beat Roger Federer (arguably the greatest player of all time), because Federer's one handed backhand is vulnerable to Nadal's lefty forehand.
In a boxing match on November 4, 1947, left-handed fighter Mike Collins emerged from his corner in a right-handed stance and then shifted into a left-handed stance, flooring his opponent and winning the match in four seconds.
It's common knowledge that professional wrestling is largely a staged fight but what isn't common knowledge is that a large part of the training is learning how to hold back so as not to seriously injure the opponent, and for the wrestlers to willingly cooperate in order to reduce injury. In essence, every match has the wrestlers fighting "left handed". While professional wrestling moves are meant more for show than for actual practical application, often telegraphing most severely, it's safe to say that if some of those moves were performed in earnest, they would hurt. A lot.
Billiards and particularly Snooker players sometimes switch hands to avoid awkward stretching across the table; some even actively train to become near-ambidextrous. However, only superstar Ronnie O'Sullivan will sometimes play entire frames left-handed just to mess with his opponent's head. Opinions differ on whether this is pure awesome or just jerkassery.
O'Sullivan once received a formal complaint about being disrespectful after playing left handed. In response he claimed that he could play better left-handed better than his opponent could play right handed. He wasn't disciplined because he proceeded to play a 3-games in a row against a professional, left handed, and won all 3.
Many left handed people will have found themselves in situations where the opposite applies. For whatever reason you will be forced to do something with your right hand and because of this will generally be pretty bad at it, but then when you get the chance to use your left hand you will surprise everyone at how much better you are. A common example is using something designed for right handed people, then switching to something that can be used by either hand.
A famous example is the "Rumble in the Jungle" fight between heavyweight boxers Muhammad Ali and George Foreman. While everyone knows the story now, back then, people had no idea Ali was intentionally holding back and letting Foreman pound him on the ropes. He told everybody who would listen that he was going to dance and make Foreman look silly, but he was bluffing. He knew Foreman was too powerful to stick and move, because all it would take was one good shot by the big man to seriously hurt him. So he laid on the ropes until Foreman punched himself into exhaustion, then he knocked him out. Ali, afterwards, called the tactic the "rope-a-dope".
Justified in the case of Károly Takács, an Olympic pistol shooter. He was already a world-class marksman when he suffered injuries to his right hand whilst handling a faulty grenade, whilst serving in the Hungarian Army. Determined to continue his shooting career however, he trained using his left hand and eventually went on to win two Gold Medals in the 1948 and 1952 Olympic Games.
Common when nations with a superior technologically advanced military, attacks a nation with an inferior and primitive military to keep civilian casualties low or avoid total destruction of the country's limited infrastructure. Sometimes an objective becomes so important to neutralize, they unleash their full might to achieve it (innocent bystanders and collateral damage be damned), showing they could actually annhilate everything if they really wanted to. Moreover they never seriously consider using a Nuke 'em to just end the conflict in 15 minutes.
Used in Cricket. While a batsman's handedness is usually known to everyone by the time they get to top level, sufficiently nimble ones can switch stances while the bowler is in mid-bowl (mid-pitch). Since players on the field in cricket are positioned asymmetrically, this completely throws off the attempted formation.