Beat Them At Their Own Game

Our hero is really in a pickle this time. The latest villain uses a unique weapon, technique or tactic which beats anything else the hero can do. So how does the hero get out of this? By using the same tactic himself!

Some authors, especially video game designers, like to have their hero use a villain's own methods against him. This could be due to the reason stated above: because the only option the hero has to counter said tactic is the tactic itself. Other times, it might be an honor thing. Or things could have just turned out that way. Whatever the reason, equally matched fights are cool.

Perhaps this is so popular in video games because it allows for variety in gameplay. In fact, many a Fisticuffs Boss fight is against a similarly unarmed opponent. When the enemy's fighting style is radically different from the hero's typical style, this can be an Unexpected Gameplay Change.

Villains can use this tactic, too. It's sometimes cited as a reason for creating an Evil Knockoff of the hero. Playing Tennis With the Boss is arguably a sub-trope of this.

Compare Faustian Rebellion, where the villains really should be in charge of the game, yet are at risk. Also compare Hoist By His Own Petard, which is where villains are defeated by their own weapon or plot, but not necessarily by a hero.

Anime

 * Beet the Vandel Buster could fight effectively against the gun-wielding Frausky only after he had learned how to properly use his own gunlike Empathic Weapon, as opposed to his other four Empathic Weapons, which are all melee.
 * The main crew of One Piece tend to fight against similarly skilled members of every Quirky Miniboss Squad they encounter: Zoro fights other swordsmen, Sanji fights martial artists and Usopp fights projectile users, while Luffy inevitably ends up going after the Big Bad for that group.
 * Lampshaded in one fight where Sanji matches up with a swordsman while Zoro finds himself squaring off with a martial artist.
 * Typically they fight similar opponents intentionally. Zoro for example wants to be the greatest swordsmen in the world, so fighting other swordsmen is a bit important for that goal.
 * The Straw Hat crew was challenged to a Davy Back Fight, where a pirate crew challenges another crew to a series of games with crew members as the prize. The Foxy Pirates used several underhand tricks to get the advantage but the Straw Hats naturally beat them.
 * The CP9, confident in their abilities, made a game out of rescuing Robin where they divided five keys among them (one which unlocked Robin's cuffs) and had the Straw Hats scramble to defeat them and find the right one before Robin was permanently taken away. We all know how that turned out.
 * Frequently used in Ranma One Half, but notably subverted and then averted when Ryoga learns the Shi Shi Hokodan technique. After being devastated by the technique, Ranma attempts to master it, but this proves impossible, as the Shi Shi Hokodan is powered by depression, and Ranma (despite all circumstances) is a pretty happy fellow compared to Ryoga, and certainly can't hope to match his misfortunes. Instead, he resorts to mastering a variant powered by his confidence. This works for a time, but Ryouga -- helped along by the depression of having his technique thwarted -- then uses the Perfect Shi Shi Hokodan. It's fueled by a level of absolute depression for which Ranma can't muster an equal amount of confidence, especially once Ranma starts losing. In the end, Ranma achieves victory by finding a way to turn Ryouga's own attack against him.
 * Bobobo Bobobobo is quite fond of using parodies of his enemies' attacks.
 * The Naruto character Kakashi Hatake is known as the "Copy-Ninja" for his ability to flawlessly copy an enemy's moves, using his Sharingan eye, even as they are performing them.
 * In one instance, the ninja he was copying was so surprised by Kakashi's perfect move for move copy that he stopped cold in the middle of his sharingan. Kakashi continued anyway and completed it despite having never seen it.
 * In an episode of The Melancholy of Haruhi Suzumiya, the SOS Brigade are challenged by the Computer Society at a video game of the latter's own design to keep their computer (and their Emotionless Girl, thanks to Haruhi's tendency to treat brigade members like property.) The SOS Brigade ends up winning in spite of only having a week of practice, having a strategic moron for a leader, and rampant cheating on the part of the Computer Society.
 * Straight example since it took rampant cheating on the part of the Emotionless Girl for them to win.
 * Technically, she didn't cheat. The only thing she did that wasn't within the rules of the game was to turn off the computer club's cheat.
 * During the Kyoto Story Arc in Rurouni Kenshin, Saitou challenges Sanosuke to hand-to-hand combat (the latter's specialty), even going so far as to suspend fighting dirty, in order to prove that Sano isn't on his or Kenshin's level (and consequently, a liability in the coming battles). Needless to say, it was a No Holds Barred Beatdown, and not in Sano's favor.
 * The favored method of the D'arby Bros. in Jo Jos Bizarre Adventure is to force the heroes to play an innocuous game (poker, a video game, or Rock-Paper-Scissors) and then cheat like hell at it to win (since, according to them, it isn't cheating if you don't get caught). Naturally, the heroes have to cheat right back while catching the D'arbys in the midst of their own cheating. The results were... memorable.
 * In Yu-Gi-Oh GX, Judai manages to defeat a deck destruction expert by deck out.
 * He also beats a guy using a quiz deck with a quiz of his own.
 * This is the tactic employed by the Anti-Spiral in Tengen Toppa Gurren Lagann - whenever the protagonists get a bigger mecha, they field an equally big one to try and instil despair into the protagonists in order to dampen their hot blood powered Spiral Energy.
 * When Kenshiro fights Shu in Fist of the North Star, he managed to defeat him through a secret Hokuto Shinken technique that allows him to emulate Nanto Seiken.
 * During his battle with Raoh, Toki artificially increases his strength to use his opponent's fighting style. Unfortunately he doesn't succeed.
 * In Magical Girl Lyrical Nanoha Strikers Nanoha defeats Teana using her own attack, Crossfire. She gets even in Vi Vid: during a 5-on-5 mock battle Nanoha and Teana use Starlight Breaker against each other, defeating most of their opponents in the process; in the end, Nanoha is shot down by her own trademark spell, while Teana (barely) remains standing.

Film

 * The final battle of Pirates of the Caribbean: Curse of the Black Pearl. In order to even the odds between himself and the cursed undead pirates, Captain Jack Sparrow picks up a gold piece from the cursed treasure trove, transforming into an immortal undead pirate himself, allowing him to more easily buy time until the curse is broken and the evil pirates are rendered killable.
 * Dutch uses stealth tactics to defeat the Predator.
 * In Predator 2, Harrigan kills the Predator with its own disc weapon.
 * In Tron Legacy, Rinzler,, uses two light discs in combat, and is considered nearly unstoppable. Sam Flynn finally defeats him by using his father's disc in conjunction with his own.

Literature

 * In Crysis: Legion it is speculated that the NYC Ceph look different from the Lingshan Ceph because of trying to imitate human equipment and tactics. It doesn't work very well.
 * In the Honor Harrington books, after repeatedly suffering losses due to Havenite deep raids, Manticore's reconstituted Eighth Fleet is tasked with doing the same right back.

Live Action TV

 * Since July 2005, when the first Formula One driver was a guest on Top Gear, none had cracked the Stig's record in the Suzuki Liana, and notably, only one actually took the same line the Stig takes going around the track (though it's speculated that the rainy weather was what handicapped him). Then Rubens Barrichello comes on the show, takes the same line as the Stig, and beats his record by a tenth of a second.
 * Too bad this show doesn't run in Brazil. That would shut some people up there.
 * In a championship round of Junkyard Wars, the Turbines stole an entire car from the Pit Crew's lot, and foiled the Crew's attempt to steal it back. This could be karma in action, as the Pit Crew had stolen some motorcycles (yes, several motorcycles) from their opponents in a previous round of the championship.
 * Before Jon Stewart took over The Daily Show and Win Ben Steins Money was in its prime, Stein was given a set of five questions to answer after an interview. The questions were outrageously difficult and based on very obscure facts. (Stein, to his credit, managed to answer one correctly.)
 * On Heroes, this is now Peter's new strategy thanks to the Discard and Draw ability that he regains after losing his original ability and taking the ability-granting formula.

Professional Wrestling

 * Many times a wrestler will have a trademark finishing maneuver. As in the WWE game cited above, a point of drama is to use a wrestler's finisher against him/her. This only works if the move in question is unique, though; there's not as much drama if Kane and The Undertaker trade Tombstones and chokeslams, since they both 'naturally' have them.
 * Also in wrestling, certain characters usually have matches that are claimed to be their specialty (The Undertaker has casket and buried alive matches, the Hardys are associated with ladders, the Dudleys with tables, Kane with the Inferno Match), but generally they tend to lose those matches.
 * At some point in The Rock's career, he began to make a habit out of hitting his opponents with their own finishers. This included giving Triple H a Pedigree onto a table, giving the Undertaker a chokeslam, spearing Goldberg, putting Kurt Angle in the ankle lock and giving Stone Cold Steve Austin lots and LOTS of Stunners. While he usually tried to pick up a pin after this, they pretty much always kicked out. Also, this usually meant that eventually the other wrestler would give him the Rock Bottom.
 * One match saw The Rock was in a Triple Threat match with Kurt Angle and The Undertaker. One point in the match saw Rock use a Chokeslam on the Undertaker, Angle using a Rock Bottom on Rock, and The Undertaker applying an Olympic Slam to Kurt Angle.
 * At Hard Justice 2008, Kurt Angle tried to use the Styles Clash on AJ Styles himself, only for Styles to turn it into the Angle Lock in midair and force Angle to tap out to his own finisher.
 * At Final Resolution 2010, Douglas Williams pinned AJ Styles after using the Styles Clash on him.
 * Kane has always been a sadistic monster (though his character goes from being a Noble Demon to a Complete Monster depending on plot) that loves playing mind games and mentally tormenting his opponents. What did Edge do when he had to beat him for the World Heavyweight Championship? Kidnapped Kane's dad and spend the next few weeks torturing Kane in all sorts of sadistic mind games and torturing his daddy. Kane tries to call him out on it, only for Edge to remind him of how he's only doing the exact same thing Kane always does. So far, it seemed Edge has one upped Kane.
 * At Sacrifice 2007, James Storm tried to attack Chris Harris with his signature beer bottle, but Harris clocked him with a bottle of his own.
 * Subverted hilariously when Vickie Guerrero attempted to Spear Edge. She comically bounces off him like he was a brick wall.

Tabletop Games

 * Averted in Dungeons and Dragons 4E; although Necrotic damage is an option, often the best weapon to fight evil with is Good. Indeed, the assassin (the first Shadow Striker) is widely regarded as one of the worst classes.

Video Games

 * In Metal Gear Solid, Solid Snake has to find a sniper rifle in order to fight Sniper Wolf, who is a Hopeless Boss Fight until you run back to find it, and you fight Revolver Ocelot early in the game when you don't have any guns heavier than a pistol. Inverted when Cyborg Ninja willingly drops his sword in order to fight you hand-to-hand, should you remove your own weapons during the fight with him.
 * And MGS2's final fight makes you battle Solidus with swords only. Here any use of guns is not possible.
 * The fourth game had a sequence where you get to . And it's awesome.
 * With the exception of the original MGS, though, this is entirely optional for the most part, as there are several ways to beat each boss or situation. With MGS3's The End, for example, you could fight fire with fire by sniping him, or you could sneak around and make the fight up close and personal. Or just run out the clock (although this takes several days without cheating).
 * Don't forget, you can snipe him long before his actual boss fight. When he is being wheeled out at the docks, you can snipe him down easily.
 * It's optional in the first MGS as well. When you fight Sniper Wolf you can take cover behind an embankment and spam Nikita missiles at her.
 * Inverted in the fight with Laughing Octopus in MGS 4, where
 * In Kingdom Hearts 2, many of Sora's Reaction Commands involve him copying the enemy's signature moves. For example, he can copy the aerial dive attack of Xaldin, and against Demyx he can challenge him to a musical duel.
 * For an earlier example, look no further than Kurt Zisa in the first game. In its first phase it only uses physical attacks. And it locks your magic forcing you to only use physical attacks. Then its second phase uses only magic based attacks. Guess what you have to use to break his shield.
 * Much of Zone of the Enders: The 2nd Runner's plot involves acquiring the Zero Shift technique so that the player's Humongous Mecha Jehuty will be able to fight on equal footing with its Evil Counterpart, Anubis.
 * Black Waltz No. 3 in Final Fantasy IX. As his name implies, he fights with black magic, and your party includes a black mage of your own, Vivi. Black Waltz also has the ability to fly into the air, making him virtually impossible to hit with short-ranged physical attacks but still easy prey for Vivi's magic. And Vivi automatically begins the battle in Trance mode, allowing him to cast two spells per turn. It's obvious what you were meant to do (not that you have to, but...)
 * Black Waltz No. 2, however, is a subversion. If you use Vivi's spells against him, he will taunt you and counter with a higher-level spell, handily discouraging you from "fighting fire with fire". And if you're wondering about Black Waltz No. 1... Vivi isn't in your party then.
 * See also Blue Magic, in which a character can learn enemy-exclusive skills, usually via getting hit with it. This includes the instant-death skills.
 * When you kill The Dragon in Rune, he falls into a pit of green goo, accidentally transforming into a super zombie. He realizes that he has basically beaten you and jumps over the Insurmountable Waist Height Fence you're now trapped behind; you then commit suicide by jumping into the goo and becoming a super zombie yourself.
 * Meta Knight, the recurring sword-wielding Worthy Opponent from the Kirby series, usually leaves a sword in the boss arena for you to take and use against him. Originally, in Kirby's Adventure, he refused to start the fight until you took it, but in Kirby Super Star, he will fight you if you wait several minutes without taking it. Because Meta Knight's attacks don't create stars for Kirby to inhale and spit, you can't hurt him without a power, meaning that you must use the sword to defeat him. Thankfully, you won't lose the sword if Meta Knight hits you.
 * You can still beat Meta Knight in Super Star even if you choose to go powerless (or if you end up losing your power), though the method of doing so isn't immediately obvious; when he uses one of his projectile attacks, inhale it and spit it back at him. However, this is much harder than just using the sword (or another power), as not only are you at the mercy of the AI Roulette, but for the first half of the fight you must wait much longer than usual between his attacks, dodging becomes crucial to success, which is much harder to do than with most other bosses (especially with his tornado attacks), he leaves almost no breathing room between attacks during the second half, and to top it off his projectiles come out fast and can easily hit you before you have a chance to inhale them if you don't react quickly. While Ultra makes it much easier by making some of his attacks produce stars, in the original SNES version a powerless MK fight is best left until you're familiar with dodging his attacks, and is only really feasible in The Arena, where there's no time limit to worry about.
 * King Dedede does the same with the Hammer power in the 'Revenge of the King' section of Kirby Super Star Ultra.
 * Miracle Matter, from Kirby 64, uses attacks based on the 7 abilities Kirby can copy. It can only be harmed by whatever ability it is copying at the moment (or by inhaling the power-granting things it drops and spitting them out at it); its immobile default form is completely invulnerable.
 * Eternal Darkness's final boss involves you
 * According to the Strategy Guide, it is almost impossible to defeat the final boss in Baldur's Gate 2 without temporarily giving into your evil nature and turning into the Slayer, which the final boss also starts the fight as. It should be noted that this is rubbish, all you really need is a strong character. They seem to like the idea of you turning into the Slayer for the final boss fight though, and the game drops hints to that near the end of the game.
 * Topo in Brave Fencer Musashi. When Musashi attempts to start a boss fight, she is aghast that he would consider hitting a girl and challenges him to a dance contest instead. Failing to copy her moves in the resulting rhythm minigame will result in being blown into an electric fence.
 * Metroid Prime: Hunters and Metroid Prime 3: Corruption both feature this trope. The final boss changes the color of its obvious weak point and its own weapon to match one of the six weapons you have at your disposal. Corruption features enemies that can enter Hyper Mode - the best counter being to do that yourself.
 * Metroid Prime also features Space Pirates who wield copies of one of your weapons and are only vulnerable to the same weapon they use.
 * Also, in Metroid Prime the fight with the Metroid Prime's exoskeleton form can only be damaged by attacking it with the weapon that corresponds to its current colour and attack pattern. What's more, Metroid Prime always needs Phazon weaponry to finish it off, which it always gives you in some way or another, be it via puddles, projectiles, or injecting you with the crap.
 * Some of the more recent WWE Wrestling Games allow players to "steal" their opponent's finisher with a special combination of buttons. This can get rather hilarious if, for example, the player is playing as The Big Show (who measures 213 cm and weighs an even 200 kg), and borrows Jeff Hardy's signature Swanton Bomb (which involves leaping off the top turnbuckle, flipping forward 270 degrees, and landing back-first across a prone opponent).
 * Swanton Bomb nothing. Have Show or Andre the Giant steal Rey Misterio's finisher--swinging kick through the ropes, land on the apron, spring to the top rope, then fly off and land sitting on the victim's shoulders, then backflip into a pin. Tell me there isn't anything more frightening than seeing a 500-pound wrestler flying groin-first at your face.
 * Or on the other side of the gamut, playing Rey Mysterio and having him do a Tombstone Piledriver on the Undertaker.
 * In Mega Man games, the titular character gains the abilities of the Robot Masters that he defeats, which are typically useful against another Robot Master. However, in Mega Man 2, Metal Man is particularly weak to his own weapon; two shots on Hard mode will take him out.
 * This is even more prominent in Mega Man 3, where every robot master is weak against his own weapon.
 * In Tak and The Power of Juju, Tak defeats Tlaloc by turning Tlaloc's sheep curse back on him.
 * In Tak 2: Staff of Dreams, Tlaloc uses half of the Staff of Dreams to turn into a huge purple monster with tiny bat wings. Tak counters by using his half of the staff to... turn into a huge blue monster with tiny bat wings.
 * The final battle of Spyro 2: Ripto's Rage involves competing with Ripto to gather orbs which give special powers to whoever collects them.
 * In Chrono Trigger, one of the fights against Magus invokes this trope; whatever magic is used against you is the only way to successfully fight back, and it changes every few rounds. This can be confusing if you're used to playing Elemental Rock Paper Scissors, though the DS version helps clear it up. For all but one party combination (and that one only works after a fair bit of Level Grinding to get Crono, Frog, and Lucca's Triple Tech), you won't be able to match one (or two) of the elements, depending on your party; hitting him physically with anyone but Frog makes him manually cycle the elements, solving that problem.
 * While most Klonoa series bosses require you to throw enemies into them, the King of Sorrow from Klonoa 2; Lunatea's Veil attacks you with spiked orbs which he controls with chains of energy. To defeat him, you have to steal one of his orbs and throw it at him; conveniently, it can be used multiple times, as it returns to you on a chain of energy after you throw it.
 * Painkiller has a demon morph Super Mode which is devastatingly effective against the game's demonic enemies.
 * The original, 2-D platformer Prince of Persia forces the player to leap through a mirror at one point, creating a "shadow twin" who bedevils the player in later levels. When the hero finally confronts his twin, the player discovers that striking the twin damages the hero, and killing the twin results in the hero's death. The only way to defeat the twin is to
 * In .hack// video games you can use Data Drain against the enemies. The same skill the 8 Phases use against people to put them into comas. In fact, Data Drain is the only way to defeat most of them.
 * Final Fantasy Tactics Advance is a good example of a game where you can cheat just as much as the computer... and possibly even more than that.
 * In the story, Marche often gets attacked by various groups of people, including bounty hunters, that tells about him when he goes out on missions. Marche, wanting to lure  out to talk with him, takes an especially promising job. He's able to defeat his foes and.
 * In Psi-Ops: The Mindgate Conspiracy telekinesis is one of the best ways to deal damage to Edgar Barret, a much stronger telekinetic specialist (how much stronger? You can throw boxes, he can throw trains!).
 * Reverse example. in Devil May Cry 3, Dante goes the whole game with his broad sword and his brother Vergil with a Katana. At the final level, Vergil gains a similar sword and starts fighting almost exactly like you, going from a Glass Cannon Ken to a full-fledged Perfect Play AI.
 * Badass as it was in the boss fight, the cutscenes make it evident that Dante was far superior with broadswords.
 * In Okami, the kitsune lord Ninetails has a Celestial Brush of its own on each of its tails. Trying to use your own Celestial Brush will make Ninetails bring up a Brush to match and disrupt your Technique, forcing you to finish the pattern as soon as possible before the enemy crosses it out.
 * Subverted in Summoner, when the White Magician Girl and The Lancer go two-on-two against the evil queen and dark prince. The queen is a powerful magician, but totally immune to magic, while the prince is a powerful swordsman, but totally immune to physical damage.
 * Not about fighting, but in Neverwinter Nights 2: Mask of the Betrayer you can help a guy from Deal With the Devil by beating the devil with its own contract.
 * The final boss of Wario Land: Shake It!, the Shake King uses the same techniques as Wario for the first stage of the battle, which includes charging and ground-pounding. Wario, who is smaller and faster can take advantage of certain things, like jumping on the Shake King while charging to disrupt him and run headfirst into a wall.
 * There's also B Bunny, a rabbit type boss in Wario Land 2 and 3 that has to be beaten at a variant of either basketball or football (soccer in the US), by using the boss as the ball. While the boss is trying to use Wario as the ball instead.
 * In case that was difficult to explain, see the end of this video.
 * Speaking of Wario, he'll try doing this to you when you fight him at the end of Super Mario Land 2. He uses a carrot on himself to give him the same flying bunny-ears power that Mario could use in the game; beat him in that form, and he picks up a Fire Flower...
 * In World of Warcraft, this is often reversed, with boss fights designed to use players' abilities against them. Herald Volazj in Anh'Kahet is one such boss, who splits the party and forces each player to fight clones of the others. A similar effect is used by Valkyr Heralds in Icecrown Citadel, who spawn copies of randomly chosen raid members that everyone must fight. Perhaps the most literal use of this, however, is in the Trial of the Crusader, whose third boss fight consists of a group of PvP opponents that behave as much like opposing players as it's possible for the game's AI to simulate. For example, crowd control abilities, normally useless on bosses, suddenly become mandatory.
 * In Pokémon, several types are weak to themselves, and in some cases, that is the only thing that is super effective. As an example, Dragon-type Pokemon are weak to Ice- and Dragon-type attacks. However, later games in the series introduce two Water/Dragon-type Pokemon, Palkia and Kingdra. The Water type cancels out the Ice-type weakness, and the Dragon type cancels all of Water-type's weaknesses, meaning that the only easy way to take one of these down is to Beat Them At Their Own Game with a Dragon-type attack.
 * The move Mirror Move allows the user to use the move just used by the opponent, and the move Transform literally allows Pokémon to beat the opponent at their own game, as the Transforming Pokémon gains access to the target's typing, stats, and moves. To a lesser extent, the move Role Play can change the user's ability to that of the target.
 * Averted in Planescape Torment: a mage duel with the final boss is impossible to win even if you cheat to get so high level the XP meter refuses to register more. Instead, you can defeat him by: beating him with something, having your buddies beat him, talking him into surrendering, talking him into suicide, nullifying him out of existance with sheer force of will, or even killing yourself.
 * In Super Paper Mario, one level has a Koopa Troopa running away from Mario, hitting a ? Block, and snagging a Mega Star to grow into a giant 8-bit version of itself and proceeds to try and crush Mario. This is more of a joke rather than a dangerous mook since running to the left snags you your own Mega Star, allowing you to thwart the Koopa with your own giant 8-bit self.
 * Additionally, unlike Mario and friends, the Koopa can be stomped out of your way as always. You simply need to gain enough height to reach his head.
 * Grand Theft Auto: San Andreas has a scene where you can fight a Vietnamese gang boss sword vs sword (he tosses one to you to duel). Of course, if by then you've picked up a shotgun, you're still more than free to use it.
 * Saints Row 2 has a similar scene where you fight a rival gang's (A yakuza style gang who fight with swords) enforcer and his men with samurai swords. Although you can't use any other weapon during this part of the game.
 * Although thanks to a glitch in this troper's game, he ended up with the taser instead of the katana.
 * The Lego Star Wars games have the player Force-pushing objects, thrown by the boss, back at the boss. Fighting Dooku even lets you do it with Force Lightning.
 * Subverted in Hype the Time Quest, the Final Boss, Barnak, has a "Smart Tornado" that follows the character. You can use this to your advantage by getting Barnak in between you and the tornado. It isn't very effective, though, and is absolutely not necessary, but fun.
 * In Red Steel (the first), your character proceeds through each level with the usual assortment of FPS firearms. The Boss Battle of each level, however, is inevitably a swordfight, requiring you to put away your guns and use your blade instead.
 * Super Smash Bros Brawl has a boss named Duon that has a melee-attacking side and a projectile-throwing side. The blog notes that it's best to match him and fight close to it when the melee side is facing you, and keep your distance from the projectile-throwing side.
 * Subverted in Doom, as the rocket-firing Cyberdemon actually takes less than normal damage from the rocket launcher, making it rather ineffective.
 * The Prowler from Assassin's Creed: Brotherhood, with his hooded robe and retractable switchblade, appears to be a Templar attempt to fight the Assassins with their own methods. In fact, the Multiplayer itself is this, being a training program used by the Templars in order to replicate Assassin techniques.
 * This is solidified in Assassin's Creed Revelations: One of the new enemy types is the Stalker, who can be dressed in white, appears out of friggin' nowhere and tries to shank you... just like you've been doing to countless Templars.
 * In Pickory, one of the boss fights is actually a clone of KSpaceDuel. You get a ship which is identical to the boss in every way.
 * A literal example: a team of League of Legends developers was beaten at League of Legends by a team of Heroes of Newerth developers, their chief competitors in the market, which is doubly ironic because HoN is considered by many to have a higher skill cap, which LoL fans often vehemently deny.
 * Kratos pulls this on
 * Don Flaminco in Punch Out uses this against you. For most opponents, you have to block or dodge their attacks and then counterattack. Don does the same trick against you, refusing to land a blow on you unless you strike first so he can counter. Of course, you can counter his counterattack.
 * In Evolva, you're forced to do this, as you must mutate to get the defeated enemies' attacks and use them against the enemies, if you don't want to complete the game only with your fists. It's still not recommended to use an attack against the enemy that gave you the attack in the first place.
 * In Skyrim, dragons have the natural ablity to use "shouts". When humanity learned how to use shouts (which the dragonborn can do as easily as a dragon) from  they developed.
 * In Sonic Colors, the Final Boss uses Wisp powers against Sonic, who had been using them up to this point, complete with even having the same announcer.
 * In the final battle of Kirbys Return to Dream Land,
 * Vitally important in both the X-COM series and UFO After Blank series. Humanity only stands a chance against the alien invaders by stealing and reverse-engineering all of their technology as quickly as possible, as well as capturing the aliens themselves, dead or alive, for dissection or interrogation respectively.
 * Vitally important in both the X-COM series and UFO After Blank series. Humanity only stands a chance against the alien invaders by stealing and reverse-engineering all of their technology as quickly as possible, as well as capturing the aliens themselves, dead or alive, for dissection or interrogation respectively.

Web Original

 * In this followup to The Horribly Slow Murderer With the Extremely Inefficient Weapon, Jack attempts this against the Ginosaji.

Western Animation
"Long Feng: You've beaten me at my own game.
 * Inverted in Samurai Jack, after Aku grows tired of sending wave after wave of bounty hunters against Jack, wondering aloud "Is there any fighting style that can defeat his!?" He decides to solve the issue by creating an Evil Twin of Jack from his hatred and anger. True enough, Jack could not defeat it in combat; instead, he defeated the clone by meditating and reaching inner peace.
 * Played straight when Jack becomes a ninja to fight a ninja.
 * Also inverted in an episode of Teen Titans, where the demon Trigon forces Cyborg, Beast Boy, and Starfire to fight the evil side of themselves--a black-and-white, evil copy of each Titan. After a long while of trying (and failing miserably) to beat themselves, they figure out that the copies can be defeated by each Titan taking down a copy other than their own.
 * Same thing happened, though on smaller scale, on Justice League Unlimited, along with a Hannibal Lecture. Superman was having problems taking down his evil clone, prompting Wonder Woman to fly in and suggesting to switch dance partners. Green Lantern and Hawkgirl end up doing the same thing. We see The Flash and Batman easily beating their own doubles, however, the Flash with a particularly effective Shut UP Hannibal, and Batman by virtue of the fact that he didn't give his double a chance to start messing with his head.
 * This also happens in one of the early Archie Sonic the Hedgehog comics, wherein the main cast has an all-out brawl with their Mirror Universe Evil Twins. The heroes start out fighting their own counterparts and neither side can gain an advantage, but after they switch partners the goodies handily tromp the baddies.
 * Ditto for the Gargoyles episode, "The Reckoning", when the Manhattan clan fight the clones that Thailog made of them.
 * Also don in an issue of Spider-Ham complete with lampshade hanging, Mooster Fantastic consult the hero's manual and find the proper tactic for dealing with evil counterparts, switching opponents!
 * Chip 'n Dale Rescue Rangers uses this in most episodes with Professor Nimnul as the villain. Most times that the Rescue Rangers go up against Nimnul, they end up turning his own inventions against him.
 * In The Twelve Tasks of Asterix they face a trial that the magic potion has no effect on... Bureaucracy! However, Asterix is smart enough to play the system against itself, causing enough chaos for the head of the place to just hand him the item to make him go away.
 * South Park: Don't try to make Cartman regret his actions and behavior using a psychology approach.
 * Avatar: The Last Airbender: Said word for word by Long Feng, but denied to Azula.

Azula: Don't flatter yourself. You were never even a player."