Unless you've got the Heart of the Cards on your side, [[ThatOneBoss these bosses]] will waste no time in stacking the deck against you and making you beg for the sweet embrace of the Shadow Realm.

[[foldercontrol]]

[[folder:''Duel Monsters'' series]]
* ''VideoGame/YuGiOhDarkDuelStories'':
** Simon Muran/Paradox. His Deck is full of Magic Cards that can reverse the flow of the Duel, and he gets them with shocking frequency. [[https://yugipedia.com/wiki/Brain_Control_(DDS) Brain Control]] to take your strongest monster for an attack or tribute, [[https://yugipedia.com/wiki/Crush_Card_(DDS) Crush Card Virus]] to wipe out your field of powerful monsters, [[https://yugipedia.com/wiki/Spellbinding_Circl Spellbinding Circle]] to weaken all your monsters to make defeating them easier, and [[https://yugipedia.com/wiki/Dian_Keto_the_Cure Dian Keto the Cure Master]] to restore 5000 of his Life Points for more chances to beat you. Oh, and he has three copies of Brain Control, Crush Card Virus, and Spellbinding Circle to hit you with. All of this on top of a solid Light/Dream Deck that uses [[https://yugipedia.com/wiki/Bright_Castle_(DDS) Bright Castle]] to increase the power of his monsters, and Simon more than earns his place here.
** Ishizu Ishtar. She uses a female monster deck like Mai, but is significantly more powerful due to her potent Magic Cards and stronger monsters. She runs three copies of [[https://yugipedia.com/wiki/Dark_Hole_(DDS) Dark Hole]], and her AI is smart enough to play them before summoning a monster to attack you directly with. Next are her three copies of [[https://yugipedia.com/wiki/Megamorph_(DDS) Megamorph]] and Spellbinding Circle, using the former to power up her monsters one at a time without a type restriction to hinder them like similar cards and the latter to weaken all your monsters at once. She even runs three copies of [[https://yugipedia.com/wiki/Swords_of_Revealin Swords of Revealing Light]], giving her a potential ''nine'' turns to stall and build up her forces while you sit there and pray for her current copy to end before she uses another.
** Priest Seto is ridiculous, even compared to his fellow Ancient Egypt bosses. He uses almost the exact same monsters Seto Kaiba uses in Domino City, so get ready to eat [[https://yugipedia.com/wiki/B.eye_White_Dragon Blue-Eyes]] if he lands it, and possesses far more powerful Magic Cards as well. He stocks three copies of Dark Hole and ''[[https://yugipedia.com/wiki/Raigeki_(DDS) Raigeki]]'', giving him six total field nukes to play against you, and Raigeki leaves his field untouched. He also has three Megamorphs to power any monsters of his he wants, meaning his beatsticks like Blue-Eyes White Dragon hit harder. Most dangerously, he possess three copies of [[https://yugipedia.com/wiki/Change_of_Heart_(DDS) Change of Heart]], which is a GameBreaker in ''Dark Duel Stories'' because its effect is permanent unlike the real-life card. He can either steal up to three of your strongest monsters from you to beat you with, or tribute them for one of his own monsters.
* Marik's [[TheDragon dragon]], Odion, may be one of the hardest opponents in some games. Since his deck seemingly consists of a majority of Trap Cards, you'll be pretty much helpless unless you use [[https://yugipedia.com/wiki/Jinzo Jinzo]] or [[https://yugipedia.com/wiki/Royal_Decree some other card that makes traps useless]]. His appearance in ''VideoGame/YuGiOhTheSacredCards'' is an exception; he has almost no Trap Cards worth noting in his Deck in that game. No, he's ThatOneBoss for a [[NoHoldsBarredBeatdown different]] [[CurbStompBattle reason]]. In a game where 4-star monsters with ATK over 1500 are a very rare commodity barring insane LevelGrinding, having an opponent spam monsters well above that, including some that hit 1950 without tributes, really freaking HURTS.
* ''VideoGame/YuGiOhReshefOfDestruction'' is infamously NintendoHard, so it's bound to have more than a few examples:
** Mai. Her non-tribute monsters have 1850 ATK or less and most of them can take advantage of the [[https://yugipedia.com/wiki/Mountain_(ROD) Mountain]] field. Also, she can power up her [[https://yugipedia.com/wiki/Harpie_Lady_(ROD) Harpie Lady]] cards by using [[https://yugipedia.com/wiki/Cyber_Shield_(ROD) Cyber Shield]] and [[https://yugipedia.com/wiki/Electro-Whip_(ROD) Electro-Whip]]. If that wasn't bad enough, her [[https://yugipedia.com/wiki/Harpie%27s_Pet_Dragon_(ROD) Harpie's Pet Dragon]] can be powered up by every Harpie-related card on the field. Also, Mai can use [[https://yugipedia.com/wiki/Elegant_Egotist_(ROD) Elegant Egotist]] to transform a Harpie Lady into [[https://yugipedia.com/wiki/Harpie_Lady_Sisters_(ROD) Harpie Lady Sisters]] to get an unwelcome stat boost when you think you have the advantage.
** Weevil, for one simple reason -- [[https://yugipedia.com/wiki/Perfectly_Ultimate_Great_Moth_(ROD) Perfectly Ultimate Great Moth]]. 3500 ATK, and his [[https://yugipedia.com/wiki/Forest_(ROD) Forest]] field powers it up by 30%. If he manages to keep [[https://yugipedia.com/wiki/Petit_Moth_(ROD) Petit Moth]] or [[https://yugipedia.com/wiki/Cocoon_of_Evolution_(ROD) Cocoon or Evolution]] in play for only a turn or two, you'll find yourself facing one of the strongest monsters in the game fighting on its home turf. Good luck. He can also use [[https://yugipedia.com/wiki/Pinch_Hopper_(ROD) Pinch Hopper]] to summon any insect from his hand. Also, he’s the first Duelist that [[TheComputerIsACheatingBastard ignores the card restrictions]].
** Arkana. He not only runs high-powered monsters, in the 1400+ range, with a variety of attributes, but he has the [[https://yugipedia.com/wiki/Yami_(ROD) Yami]] field to give all of them 30% power bonuses and several power-up cards for them too, letting him quickly blast apart your Life Points with only a turn or two of leeway if you can't get an advantage on him.
** Marik runs high-powered monsters in a variety of attributes, so it's pretty much impossible to stack your deck with [[ElementalRockPaperScissors opposing-attribute monsters]] like many other opponents. He'll use [[https://yugipedia.com/wiki/Newdoria_(ROD) Newdoria]], [[https://yugipedia.com/wiki/Widespread_Ruin_(ROD) Widespread Ruin]], and [[https://yugipedia.com/wiki/Raigeki_(ROD) Raigeki]] to destroy your monsters, [[https://yugipedia.com/wiki/Viser_Des_(ROD) Viser Des]] and [[https://yugipedia.com/wiki/Spellbinding_Circle_(ROD) Spellbinding Circle]] to sap their power, [[https://yugipedia.com/wiki/Swords_of_Revealing_Light_(ROD) Swords of Revealing Light]] to stop them from attacking, and then [[https://yugipedia.com/wiki/Monster_Reborn_(ROD) Monster Reborn]] to revive them for his own usage. Oh, and he'll heal himself with [[https://yugipedia.com/wiki/Soul_of_the_Pure_(ROD) Soul of the Pure]] to keep the fight going longer than it should.
** Odion is a SkippableBoss faced before Marik, but he's no slouch either. He runs a ''lot'' of Traps, so when you attack there's no telling what's coming, but odds are it's going to destroy whatever you attacked with or at least stop its attack. He also runs three Swords of Revealing Light, three Monster Reborn, several field-clearing cards like [[https://yugipedia.com/wiki/Heavy_Storm_(ROD) Heavy Storm]], Raigeki, and [[https://yugipedia.com/wiki/Dark_Hole_(ROD) Dark Hole]], and finally he has several powerful Tribute monsters, including the [[NonElemental Divine-attribute]] [[https://yugipedia.com/wiki/Tri-Horned_Dragon_(ROD) Tri-Horned Dragon]]. It's a feat if you manage to beat both Odion and Marik back-to-back; most players would just save themselves the trouble and take on only Marik.
** Simon Muran/Paradox. He runs monsters with upwards of 1600 points in most every attribute in the game, making it impossible to reliably counter him via ElementalRockPaperScissors. Further, he has several Tribute monsters that are Divine-attribute, completely immune to that strategy anyway. Simon only runs three Spell and Trap cards, unlike other Duelists up to that point. This means his deck is almost entirely composed of monster cards, hence he'll be able to summon those high-powered monsters every single turn with no let-up. If you manage to summon a good monster against him, you still aren't safe, because he has [[https://yugipedia.com/wiki/Reflect_Bounder_(ROD) Reflect Bounder]] to deal damage to you equal to your monster's ATK. Finally, he's fought at the end of the Millennium Guardian BossRush, so you probably aren't in the best of shape in the first place.
** The FinalBoss Reshef The Dark Being is one of the hardest fights in any ''Yu-Gi-Oh'' game. His 4-Star monsters have 1900 attack points on average, and gain a 30% boost from the Yami field. Reshef also has 3 copies of [[https://yugipedia.com/wiki/Castle_of_Dark_Illusions_(ROD) Castle of Dark Illusions]], with both its anime DEF value of 2500 and its anime effect of creating the Yami field ''every turn it's out'', in case you thought it'd be simple to counter his field with a different one. Worse is Reshef's tribute monsters are the same Egyptian God Cards you spent the whole game assembling to beat him with, and he has multiple copies of Pot of Greed, Swords of Revealing Light, and Change of Heart to summon them faster. Facing Slifer or Obelisk is bad enough, but the worst-case scenario is what happens if he summons Ra; Reshef will use Ra's effect to OneHitKill you if he has a great enough life point lead, and he starts the duel with ''40,000'' life points compared to your maximum 8000. And he comes after the boss fight with Sol Chevalsky as well, so if you lose to him you have to beat Sol to get back to Reshef without saving. And on top of all this madness, [[TheAllSeeingAI Reshef can see your hand]].
[[/folder]]

[[folder:''True Duel Monsters'' series]]
* ''VideoGame/YuGiOhForbiddenMemories'' has a reputation for being one of the hardest ''Yu-Gi-Oh'' games, mainly due to these bosses.
** Pegasus has a chance of having a [[InfinityPlusOneSword Meteor B. Dragon]] as well as three (and sometimes ''four'') Raigeki. He also has Dragon Capture Jars in a game where dragons are your main fighting force. True to the anime, he's also programmed to [[TheAllSeeingAI be able to see what cards are in your hand, as well as what cards you have face down]], making him impossible to bluff. On top of ''that'', he gives some of the best magic and traps in the game, meaning you're going to be fighting him a lot in free duel. S-Tecing him can be even more of a pain.
** High Mage Kepura is the most difficult of the high mages you'll face, and is as difficult as what you'll face in the endgame, using Gate Guardian powered up by the meadow you duel him on. With an attack over 4000, it'll take just two direct attacks from it to be defeated. If given the opportunity, he'll often equip his Gate Guardian to make it even more powerful. If you takes too long to defeat him, he will summon [[StoneWall defensive monsters such as Wall Shadow or Millennium Shield]] to stall the game [[FromBadToWorse until he draws another Gate Guardian]]. Even the Meteor Black Dragon alone won't gain you victory here.
** Priest Seto, in your third encounter with him. Easily the most challenging opponent in the game, primarily for [[ThatOneAttack a single card]]: [[https://yugipedia.com/wiki/Blue-eyes_Ultimate_Dragon_(FMR) Blue-Eyes Ultimate Dragon]], which in this game is treated as a Normal Monster. Monster removal cards are incredibly hard to come by in this game, but in this Duel, they are an utter necessity, as there is no card in the game that can overpower Blue-Eyes Ultimate Dragon even with a Guardian Star boost. And just to add far too much FakeDifficulty into the mix, you fight Seto at the end of a long BossRush campaign, which [[CheckpointStarvation lacks any chance to save]]. Which means you will have to fight these guys over. And over. And over again. Oh, and by the way, Seto isn't the last battle in said BossRush. Who is? Why, the final boss, of course, who has two phases. Thankfully, even the final boss isn't as bad as Seto, but if you get bad draws... well, let's just say tears will be shed.
** Nitemare, the FinalBoss of the game, qualifies as well. He has a deck with all of the most powerful monsters in the game, including Blue-Eyes Ultimate Dragon and Gate Guardian. While he doesn't have any magic or traps in his deck, this serves as a double-edged sword: if you can make a monster capable of destroying the Blue-Eyes Ultimate Dragon, you have just guaranteed yourself a victory no matter how badly you were losing before (as long as you don't make any stupid mistakes). However, his lack of magic and traps means that he can't be stalled out either, as he'll instead summon monsters every turn that can overwhelm the player's defenses. As many speedrunners would attest, a duel with Nitemare will result in either a fast win or a fast loss, and a loss means starting all over again at the beginning of the final gauntlet.
* ''VideoGame/YuGiOhTheDuelistsOfTheRoses'' has several tough bosses.
** Tea is the first opponent dueled in the Yorkist Side of the game. Her Fairy Deck is built around strengthening her monsters and weakening your own monsters with Spells and Traps, meaning if you don't get something strong and maintain it she'll chip away at your LP.
** Mai has a [[https://yugipedia.com/wiki/Mountain_(DOR) Mountain]]-themed Deck and terrain which strengthens her own monsters. If you picked the Zombie Deck to play with, Zombies lose strength on that field. Not to mention she has a card that disables Defense Position and she enjoys getting out [[https://yugipedia.com/wiki/Harpie_Lady_(DOR) Harpie Ladie]]s and [[https://yugipedia.com/wiki/Harpie%27s_Pet_Dragon_(DOR) Harpie's Pet Dragon]], which gains strength for every Harpie on the field as well.
** Bonz has an insanely low Deck Cost, crippling your own Deck, while his Zombies gain power from the field. He also has [[https://yugipedia.com/wiki/Pumpking_the_King_of_Ghosts_(DOR) Pumpking]], which is a GameBreaker that increases the strength of his zombies by 100 points every turn, including itself. And if he has more than one Pumpking, those boosts stack. And Pumpking is very easy to fuse with low Deck Cost monsters, even when you don't have one to just play outright.
** Yami Bakura runs the same sort of deck as Bonz, but with Plants, crippling your deck cost. What makes him hard besides that is the [[https://yugipedia.com/wiki/Crush Crush]] terrain, which destroys any monster with over 1500 ATK. To make matters worse, if you lose, he accuses you of calling him a coward before boasting about how unstoppable he is.
** On the Lancaster side, we have Pegasus, with his [[TheAllSeeingAI Millennium Eye, which lets him see your hand and every facedown you have]]. He doesn't even bother pretending he can't see your facedowns, which most of the others will do at least some of the time. Not only can he evaluate attacks correctly against your facedowns after terrain effects, even when yours is boosted, he is smart enough to use [[https://yugipedia.com/wiki/Change_of_Heart_(DOR) Change of Heart]] and [[https://yugipedia.com/wiki/Brain_Control_(DOR) Brain Control]] to do direct attacks against your Deck Leader when they are possible (and only those times). Even when a human wouldn't know that the one with the highest attack is your Deck Leader facedown, he knows, will cast Brain Control, and will hit you for 3000+ points with your facedown. Pretty much your only chance against him is to use Game Breakers of your own back. Fortunately there are plenty of them to be found, some of which are available on your first playthrough if you picked Lancaster first.
** Weevil is no slouch either, and has one of the most broken cards in the game, [[https://yugipedia.com/wiki/Perfectly_Ultimate_Great_Moth_(DOR) Perfectly Ultimate Great Moth]]. As long as it's in Defense Position, it drains all your monsters 100 ATK and DEF each turn. Even the facedowns, revealing which are Spells/Traps and which are monsters. He doesn't always get it out, but if he does, you will have a lot of difficulty winning. Even if he doesn't get it out, he, like everyone else in the game, [[WakeUpCallBoss knows how to fuse well, and if you don't, he will stomp you]].
** Rex's Dinosaur monsters are powered up by [[https://yugipedia.com/wiki/Wasteland_(DOR) Wasteland]] terrain, making them incredibly strong without the need for Fusions. If he gets lucky with Fusions, he can summon [[https://yugipedia.com/wiki/Bracchio-raidus_(DOR) Bracchio-raidus]], crippling your chances at winning. Your best shot is to simply overpower him, but that's not something that's always feasible, since he's one of the first opponents that has to be fought and Weevil, the only other opponent you can face, gives monsters that do poorly on his terrain.
[[/folder]]

[[folder:''World Championship'' series]]
* In ''World Championship Tournament 2004'', every single one of the higher-level Duelists has no strategy other than "Use [[https://yugipedia.com/wiki/Dark_Hole Dark Hole]] or [[https://yugipedia.com/wiki/Raigeki Raigeki]] to wipe out all your monsters." They almost always have multiple [[https://yugipedia.com/wiki/Mirror_Force Mirror Force]]s, [[https://yugipedia.com/wiki/Magic_Cylinder Magic Cylinder]]s, or [[https://yugipedia.com/wiki/Negate_Attack Negate Attack]]s put down. You'll use up half your hand getting rid of their traps and stopping their monsters, finally take something out of their Life Points... then they play Dark Hole and you have to find an entirely new way to get past their defenses. Even worse, they have more than three copies of some cards which you're legally only allowed to have one copy of in your Deck. What's more frustrating is that ''World Championship Tournament 2004'' has a "luck" system where the AI will almost always immediately draw these monster-destruction cards if it starts to lose, ensuring the player cannot keep a powerful monster on the field for long. You basically [[LuckBasedMission have to get lucky]] and hope the luck system does not activate before you can beat the opponent.
* In ''7 Trials To Glory: World Championship Tournament 2005'', we have the imaginatively named R. Hunter[[note]][[CharacterNameLimits short for "Rare Hunter"]][[/note]], the hardest Duelist in the game. He’s found in Shadow World, in which Duelists can use horrific Decks with multiple copies of Forbidden and Limited cards. He uses three copies of each [[https://yugipedia.com/wiki/Exodia_the_Forbidden_One Exodia]] piece except the head, so if you’re unlucky, he can beat you in two turns or even on your first turn. It really says something when Marik, who has three copies of each of the [[https://yugipedia.com/wiki/Chaos_Emperor_Dragon_-_Envoy_of_the_End Chaos]] [[https://yugipedia.com/wiki/Black_Luster_Soldier_-_Envoy_of_the_Beginning Envoys]] in his Shadow Deck (which were {{Game Breaker}}s in the real-life game even after being limited to one each, and this game was released before Chaos Emperor Dragon was {{nerf}}ed), is much, much easier to beat than R. Hunter. Your one solace is that in the Shadow World, you're not bound by the banlist either, so you have the ability to abuse as many Game Breakers as you please to even the playing field -- even if it means beating R. Hunter in a MirrorMatch.
** If you’re using an Exodia Deck in the Dark/Survival Match in Shadow World, Marik and Arkana are the most dangerous Duelists, as they both have three copies of [[https://yugipedia.com/wiki/Card_Destruction Card Destruction]] in their Decks for sending all your Exodia pieces to the Graveyard if you’re unlucky.
* ''Ultimate Masters: World Championship Tournament 2006'' has some really tough Theme Duels, such as the Spell Counter (Use 15 Spell Counters and win), Dark Scorpion Gang (Use [[https://yugipedia.com/wiki/Dark_Scorpion_Combination Dark Scorpion Combination]] and win) and [[https://yugipedia.com/wiki/Victory_Dragon Victory D.]] (Win with said card) Duels. Expect to stall hard in order to pull these off.
** The Quick-Play Spell and Counter Trap Theme Duels are extremely annoying since you have to activate 10 of said cards in the Duel during the opponent's turn. That's a quarter of your Deck devoted to one specific reactionary card type. Even worse are the opponent's Decks being so simple and easy to defeat that it's entirely possible to end the duel by accident.
** The Ritual Summon and Fusion Summon Theme Duels require you to do 10 of each during the Duel, forcing you to use said monsters for the Special Summons themselves. And no, the Duelists you fight ''do'' have the capability to steamroll over you if you're too busy fulfilling the Theme.
** A few of the Limited Duels were just plain messed up as well, such as No Setting Cards, No Attacks, and the dreaded No Normal Summons, since ''[[MyRulesAreNotYourRules the programming couldn't restrict the CPU opponent to abide by the same rules]]''.
** The Limited Duels for specific banlists are taken from (at the time) tournament-winning Decks. If you don't abuse the game-breaking combos or cards that were removed from later banlists, you'll be stuck dealing with those Game Breakers yourself.
* ''World Championship 2008'':
** The boss of the third Duel World is Speed Guardian Ferrario. The fight consists of three consecutive Duels, in which he changes his Deck every time and you do not get any recovery in between. While his first Deck is a bit of a pushover, his second is the infamous-at-the-time [[https://yugipedia.com/wiki/Diamond_Dude_Turbo Diamond Dude Turbo]] to cheat around the costs of various Spells, like the field-wiping [[https://yugipedia.com/wiki/Ojama_Delta_Hurricane!! Ojama Delta Hurricane!!]], or [[https://yugipedia.com/wiki/Bonding_-_H2O Bonding - H2O]] to cough up [[https://yugipedia.com/wiki/Water_Dragon Water Dragon]] [[AwesomeButImpractical (a strong monster that is otherwise difficult to Summon)]].
** The penultimate boss team of the World of Darkness is the Alien Shocktrooper & Alien Infiltrator Tag Team. The catch to this is that you need to beat them while the ''entire Duel'' is AI-controlled. Tag Duels are long enough on their own; watching one without any player interaction is ''boring'', and the AI can make some [[ArtificialStupidity questionable decisions]] that can cause the match to go horribly awry.
** One of the hardest tag team Duels in the game is Spirit Reaper & Marshmallon. Their strategy revolves around [[https://yugipedia.com/wiki/Final_Countdown Final Countdown]], which ends the Duel in their favor if you can’t win in 20 turns, [[https://yugipedia.com/wiki/Nightmare%27s_Steelcage Nightmare’s Steelcage]], which stops either side from attacking for two turns, [[https://yugipedia.com/wiki/Stumbling Stumbling]], which forces any monster Summoned to be turned to Defense Position (preventing it from attacking that turn), [[https://yugipedia.com/wiki/Spell_Absorption Spell Absorption]], and [[https://yugipedia.com/wiki/Solemn_Wishes Solemn Wishes]], which increase their LP by 500 points every time a Spell Card is activated and every time they draw a card, respectively. They also run a ton of monsters that can’t be destroyed in battle, or that bounce your cards to your hand, like [[https://yugipedia.com/wiki/Marshmallon Marshmallon]], [[https://yugipedia.com/wiki/Spirit_Reaper Spirit Reaper]], and [[https://yugipedia.com/wiki/Wall_of_Illusion Wall of Illusion]], as well as [[https://yugipedia.com/wiki/Waboku Waboku]], which negates any battle damage. And because this is a Tag Duel, you have half as many turns of agency while the clock is ticking, while the other half of the turns your team takes involves hoping your AI partner doesn't do anything stupid.
** After beating the opponents in Duel World enough times, several stone monuments appear depicting a particular boss monster. To unlock their rewards, the player needs to engage the monument's Duel Spirit, summon the monster depicted on that monument, and then win the Duel. Much like Theme Duels in ''2006'', you'll have to do a bit of stalling to avoid ending the Duel too quickly, but fortunately you're also in a mirror match where the opponent's Deck is about as clunky as yours. However, two of these monument Duels -- Vennominaga the Deity of Poisonous Snakes and Exodius the Ultimate Forbidden Lord-- require you to not just summon their [[https://yugipedia.com/wiki/Vennominaga_the_Deity_of_Poisonous_Snakes respective]] [[https://yugipedia.com/wiki/Exodius_the_Ultimate_Forbidden_Lord monsters]], but also trigger their special InstantWinCondition. See the [[AwesomeButImpractical/YuGiOh Awesome But Impractical page]] detailing how hard it is to get those cards to work, even in a clunky mirror match.
* ''World Championship 2009: Stardust Accelerator'':
** The Four Clone fight is unanimously considered the most difficult fight in the game by a huge margin. As the name implies, it is a BossRush, so you cannot simply restructure your Deck to beat one or the others will crush you. The first one is hard but not ridiculous, the second is a pushover, but the third will absolutely wipe the floor with you unless they get ridiculously unlucky, as it is built around [[https://yugipedia.com/wiki/Lightsworn Lightsworn]]s, one of the most notorious archetypes at the time of the game's release. And the fourth is '''[[SerialEscalation even worse than the third]]''', running a [[https://yugipedia.com/wiki/Teleport_Dark_Armed TeleDAD]] Deck (which, for those not familiar with competitive play, was widely considered the most dangerous Deck anyone could run at the time ''Stardust Accelerator'' was released). And to make matters worse, your Life Points carry over to your next opponent for no good reason. Did you just barely beat your third opponent with a few hundred Life Points left? Yeah...''good luck''. Oh, and if you're planning on boosting your Life Points to stock up for the last fights? So sorry. [[TheComputerIsACheatingBastard The game rounds down whatever life you had to 10000 for each fight, but never rounds up.]]
** Though not nearly as bad as the Four Clones, there's also Lenny. You face him very early in the game, where it's unlikely you'll have any powerful monsters with over 2400 ATK, or many monster-removal cards. Lenny plays an incredibly nasty Insect deck filled with 2600-2800 ATK monsters that he can Summon for virtually no cost, and loves to spam [[https://yugipedia.com/wiki/Dimensional_Prison Dimensional Prison]] every time you try to attack him.
** The Free Duel mode of this game has a killer tag team, Submarineroid & Fenrir. Submarineroid can use [[https://yugipedia.com/wiki/Submarineroid its own card]], which makes direct attacks, and uses [[https://yugipedia.com/wiki/Robbin%27_Goblin Robbin' Goblin]], a Trap that makes you discard every time it does; Fenrir also uses [[https://yugipedia.com/wiki/Fenrir its own card]], which only has 1400 ATK, but causes you to skip your Draw Phase every time it destroys a monster, and uses [[https://yugipedia.com/wiki/Ojama_Trio Ojama Trio]] to ensure you always control monsters... which are no defense against Submarineroid. And both use WATER monsters, which they can banish to summon Fenrir's card. After only a few turns, you and your partner likely won't have any way to fight back, period, unless you manage to summon something powerful and keep it alive early.
* ''World Championship 2010: Reverse of Arcadia'':
** It's already bad enough that you're faced with Dark Signer [[DubNameChange Greiger]]/Bommer shortly after being introduced to Turbo Duels, which forces you to adapt to the new format with limited supplies (for the uninitiated, while you can carry over monsters and Traps into a Turbo Deck, you'll need to switch your Spell Cards for Speed Spells). It's especially tough when you consider you're using said limited supplies against a deck that specializes in field control and burn damage, combining Greiger's signature [[https://yugipedia.com/wiki/Reactor Reactor]] monsters with cards like [[https://yugipedia.com/wiki/Gravekeeper%27s_Guard Gravekeeper's Guard]], [[https://yugipedia.com/wiki/Spirit_Reaper Spirit Reaper]], and [[https://yugipedia.com/wiki/Blast_Sphere Blast Sphere]]. But the main reason this Duel is so difficult is because Greiger requires you to defeat him after he's summoned his [[https://yugipedia.com/wiki/Earthbound_Immortal Earthbound Immortal]]. Bear in mind that in Turbo Duels, the normal AchillesHeel of the Earthbound Immortal is all but nullified due to the Field Spell being un-removable. If Greiger's only monster is his Earthbound Immortal, you can't attack him at all since the Earthbound Immortal can't be attacked either, and this can bring a planned assault to a screeching halt. And don't think you can just stall Greiger by preventing his Immortal from attacking. His Immortal is [[https://yugipedia.com/wiki/Earthbound_Immortal_Chacu_Challhua Chacu Challhua]], which has the ability to inflict half its DEF in damage to you in exchange for being unable to attack for the turn.
** Dark Signer [[DubNameChange Kalin]]/Kiryu forces both you and him to begin with no cards in hand, giving his [[https://yugipedia.com/wiki/Infernity Infernity]] Deck an unfair advantage right off the bat. It can turn into an extremely LuckBasedMission as you'll literally have to topdeck the right cards to establish an advantage while you can.
* ''World Championship 2011: Over the Nexus'':
** Near the end of Chapter 2, you'll have to face [[DubNameChange The Enforcers]]/Team Satisfaction. Kalin is pretty easy, despite having a few powerful cards. Crow uses an average [[https://yugipedia.com/wiki/Blackwing Blackwing]] Deck, and despite having a solid synergy, his other cards lack the punch. Jack uses some powerful monsters, but you can manage with some destruction Spells and Traps... and then you duel Yusei. Yusei uses a [[https://yugipedia.com/wiki/Quickdraw_Dandywarrior Quickdraw Dandywarrior]] Deck, known for being ''the top tier tournament Deck at the time''. While this is a fair one-on-one Duel, it is only halfway through the game, and [[WakeUpCallBoss there's no way you're ready to face that kind of Deck yet]]. Fortunately, you can still proceed with the plot if you lose to any of the Duelists in this chapter, but it's a rude awakening nonetheless.
** At the climax of Chapter 5, you and Kalin will face Lawton 2 on 1. But Lawton uses an infinitely annoying [[https://yugipedia.com/wiki/Burn_Deck burn Deck]], and he ''starts with ten cards in hand'', and will burn your LP into a critical amount the first chance he gets. Unless you've got some card that blocks effect damage, be prepared to lose a lot of Life Points when it's his turn. Worst case scenario, ''7600''. '''In one turn'''. If you fail the Crash Town QuickTimeEvent that would let you pick who starts, Lawton will go first, in which case your computer "partner" Kalin will move after that, likely running into some kind of damage-dealing Trap. And then it's Lawton's turn once more before you finally get to play ...if you haven't lost by then.
[[/folder]]

[[folder:''Tag Force'' series]]
* ''Yu-Gi-Oh GX Tag Force 2'':
** Jaden's storyline gives us a Tag Duel against Sarina and a mirror image of Sarina. Who are both running Exodia Decks that abuse a loop of [[https://yugipedia.com/wiki/Card_of_Safe_Return Card of Safe Return]] and [[https://yugipedia.com/wiki/Manticore_of_Darkness Manticore of Darkness]] to run through their entire Deck in one turn.
* ''Yu-Gi-Oh GX Tag Force 3'':
** Pairing up with Viper is a nightmare, because his AI is one of the dumbest in the game. If you only have one [[https://yugipedia.com/wiki/Venom Venom]] monster to defend you and the Trap Card [[https://yugipedia.com/wiki/Offering_to_the_Snake_Deity Offering to the Snake Deity]] is set, he'll use it as soon as he can to blow up your only defenses and take out two of his. In short, he's not a big-picture thinker, and he will frustrate you with his playstyle. Furthermore, the Special Duels (boss Duels all players go through when selecting a partner from the "Partner 2" category) he goes against are all painfully terrifying. Crowler & Tyranno can overpower the Venom monsters and blow up your [[https://yugipedia.com/wiki/Venom_Swamp Venom Swamp]]s, Atticus & the Gravekeeper can swarm and disable Graveyard access to [[https://yugipedia.com/wiki/Vennominon_the_King_of_Poisonous_Snakes Vennominon]], and Amnael & Adrian are likely to banish your monsters, depriving Vennominon of its power source.
** Pairing up with Fontaine presents similar problems but for a different reason. Her deck isn't horrible, exactly, but it has no sense of timing. She uses a [[https://yugipedia.com/wiki/Anti-Cure Simochi]] Deck which revolve around using [[https://yugipedia.com/wiki/Bad_Reaction_to_Simochi Bad Reaction to Simochi]] and [[https://yugipedia.com/wiki/Darklord_Nurse_Reficule Nurse Reficule the Fallen One]][[note]]now renamed to "Darklord Nurse Reficule"[[/note]] to cause the opponent to lose LP instead of gaining it. But, as the AI doesn't use the cards in the correct order, she'll end up giving the enemy more LP than she would deduct. Not helping matters is that cards needed to support her are in a pack that's difficult to unlock in its own right.
[[/folder]]

[[folder:''Duel Links'']]
Several Legendary Duelists at max level in ''VideoGame/YuGiOhDuelLinks'' are this, primarily for having powerful cards unavailable to the player.
* Mai Valentine at Level 40 (and even Level 30) is one of the hardest Legendary Duelists to beat, let alone farm for RandomDrops, because her [[https://yugipedia.com/wiki/Amazoness_Village_(Duel_Links) Amazoness Village]] can replace any fallen [[https://yugipedia.com/wiki/Amazoness Amazoness]] once per turn, she runs plenty of Trap Cards to revive them from the Graveyard, and she has cards like [[https://yugipedia.com/wiki/Amazoness_Fighting_Spirit_(Duel_Links) Amazoness Fighting Spirit]] and [[https://yugipedia.com/wiki/Amazoness_Spellcaster_(Duel_Links) Amazoness Spellcaster]]s to overpower most monsters you could throw at her. Unfortunately, two late-stage missions require you to win three consecutive victories against her and achieve three Quick Victories with Joey Wheeler (in two of your turns. Fortunately, these don't have to be consecutive) respectively.
* Ishizu Ishtar's Level 40 Deck, much to the chagrin of those seeking to build a [[https://yugipedia.com/wiki/Gravekeeper%27s Gravekeeper]] Deck. It features [[https://yugipedia.com/wiki/Necrovalley_(Duel_Links) Necrovalley]] to boost her Gravekeepers by an unprecedented 500 ATK and DEF, as well as a hard-to-defeat boss monster in [[https://yugipedia.com/wiki/Gravekeeper%27s_Visionary_(Duel_Links) Gravekeeper's Visionary]], which gains power for every Gravekeeper in the Graveyard and can protect itself from destruction by discarding Gravekeeper's monsters. [[https://yugipedia.com/wiki/Gravekeeper%27s_Assailant_(Duel_Links) Gravekeeper's Assailant]] also has its effect readily accessible to strike your powerhouses at their (usually) weaker DEF.
* Seto Kaiba's Level 40 Deck is regarded as ''the'' hardest to beat. He runs the 1900 ATK Level 4 [[https://yugipedia.com/wiki/Vorse_Raider_(Duel_Links) Vorse Raider]], which is more powerful than anything in the current card pool, as well as [[https://yugipedia.com/wiki/Cost_Down_(Duel_Links) Cost Down]] to easily bring out a 2400 ATK [[https://yugipedia.com/wiki/Luster_Dragon_2_(Duel_Links) Luster Dragon #2]] for no Tribute or his signature [[https://yugipedia.com/wiki/Blue-Eyes_White_Dragon_(Duel_Links) Blue-Eyes White Dragon]] for only one. And just in case you try to overpower him with a large monster, he also runs [[https://yugipedia.com/wiki/D.D._Warrior_(Duel_Links) D.D. Warrior]] to banish any of your monsters or [[https://yugipedia.com/wiki/Enemy_Controller_(Duel_Links) Enemy Controller]] to steal your monster and finish off your Life Points, or protect himself from attacks by switching your monsters to Defense Position. Unfortunately, the latter is also one of his drops and a metagame staple. Also, like Mai, you have to win three times consecutively against him for a late-stage mission.
* Level 50 Yami Bakura runs a [[https://yugipedia.com/wiki/Dark_Master_-_Zorc_(Duel_Links) Dark Master - Zorc]] Deck revolving around disruption, [[https://yugipedia.com/wiki/Dark_Necrofear_(Duel_Links) Dark Necrofear]], Zorc's die rolls, and [[https://yugipedia.com/wiki/Destiny_Board_(Duel_Links) Destiny Board]]. [[https://yugipedia.com/wiki/Destiny_Board_of_Doom Destiny Board of Doom]] is also in effect, forcing you to play on a time limit if you're unable to remove Dark Necrofear from his Graveyard. His Level 40 Evil Incarnate Deck in his Zombie mini-event was also notoriously difficult, running multiple copies of [[https://yugipedia.com/wiki/Tribute_to_The_Doomed_(Duel_Links) Tribute to the Doomed]], [[https://yugipedia.com/wiki/Book_of_Life_(Duel_Links) Book of Life]], and [[https://yugipedia.com/wiki/Sakuretsu_Armor_(Duel_Links) Sakuretsu Armor]] to stymie whatever the player tried, along with monsters of 1800 ATK and higher.
[[/folder]]

[[folder:''Legacy of the Duelist'']]
''VideoGame/YuGiOhLegacyOfTheDuelist'' has completely SchizophrenicDifficulty, so you're bound to hit some infamous roadblocks:
* The hardest Duel in the game is Aster versus Jaden - specifically, the Duel meant to represent Aster's CurbStompBattle when he revealed his [[https://yugipedia.com/wiki/Destiny_HERO Destiny HERO]]es. Problem is, Aster has TheMagicPokerEquation, and you don't; you have to run the same Elemental HERO/Destiny HERO combo he does, a combo that has absolutely no synergy whatsoever. On top of that, the Destiny [=HEROes=] Aster runs in that Deck are some of the worst available, and the Deck as a whole has almost no offensive potential unless you get insanely lucky. Jaden's [[https://yugipedia.com/wiki/Elemental_HERO Elemental HERO]]es are played pure, more consistent, and flat-out better than your cards.
* The Jaden/Alexis duel (Based on the duel where Alexis was brainwashed by Sartorius, using a [[https://yugipedia.com/wiki/White_Night White Night]] Deck) is similarly hard, for more or less the same reason: because Jaden finished the duel with [[https://yugipedia.com/wiki/Elemental_HERO_Flare_Neos Flare Neos]] and didn't use [[https://yugipedia.com/wiki/Neo_Space Neo Space]] in that Duel, Flare Neos is your only Fusion and you don't get Neo Space. What you do get is a ton of bricky or useless cards, including [[https://yugipedia.com/wiki/Spark_Blaster Spark Blaster]], [[https://yugipedia.com/wiki/Neo-Spacian_Air_Hummingbird Air Hummingbird]], and [[https://yugipedia.com/wiki/Ojama_Black Ojama Black]], cards that have no synergy whatsoever. Alexis, on the other hand, runs an [[https://yugipedia.com/wiki/Ice_Counter Ice Counter]] Deck that's extremely capable of shutting down your meager offensive options. Even if you do manage to summon Flare Neos under ideal circumstances, it doesn't have enough power to OTK Alexis, and it will have to because [[HourOfPower it returns to the Extra Deck at the end of your turn]].
* Seeker is something of a case of this; he runs three copies of every Exodia part and multiple banned draw cards. Dueling him is entirely a LuckBasedMission; if he gets even slightly lucky on his opening hand, he will win on his first turn. And on top of that, Yugi's deck is pretty poor offensively, meaning Seeker will usually survive long enough to get a few more draws in. He'll brick eventually, but he's likely going to beat you at least once before that happens.
* The first Yugi/Weevil duel becomes this if you play as Weevil using his Deck. Weevil has virtually no high-ATK monsters in his Deck. Yugi, on the other hand, has his standard Deck, which has three high-ATK monsters that can be Tribute Summoned. Weevil's only high-ATK monsters are the two monsters considered to have the worst summoning conditions in the entire game: [[https://yugipedia.com/wiki/Great_Moth Great Moth]] and [[https://yugipedia.com/wiki/Perfectly_Ultimate_Great_Moth Perfectly Ultimate Great Moth]]. In order to summon them, you have to be extraordinarily lucky enough to draw four cards: [[https://yugipedia.com/wiki/Petit_Moth Petit Moth]], [[https://yugipedia.com/wiki/Cocoon_of_Evolution Cocoon of Evolution]] to equip to it, either the Great Moth or Perfectly Ultimate Great Moth to be summoned by Tributing a Petit Moth with a Cocoon of Evolution equipped ''after four to six'' turns, and [[https://yugipedia.com/wiki/Swords_of_Revealing_Light Swords of Revealing Light]] to buy you time, without which your Petit Moth is unlikely to ever last that many turns. While Cocoon of Evolution can get a boost from the [[https://yugipedia.com/wiki/Forest Forest]] Field Spell to achieve 2200 DEF, increasing its survivability, Yugi will almost always have enough time to draw and summon his [[https://yugipedia.com/wiki/Dark_Magician Dark Magician]] (2500 ATK) or [[https://yugipedia.com/wiki/Gaia_The_Fierce_Knight Gaia The Fierce Knight]] (2300 ATK). Weevil's deck has absolutely no answers to either monster, and [[OhMyGods Ra help you]] if Yugi Fusion Summons [[https://yugipedia.com/wiki/Gaia_the_Dragon_Champion Gaia the Dragon Champion]] (2600 ATK). But really, it just makes sense; Weevil is a WarmUpBoss when played as Yugi, what makes you think you'd have better luck than the AI?
* For much the same reason as the above, playing as Kaiba against Yugi in their first Duel is pretty much impossible. Yugi's Deck in that Duel is an [[https://yugipedia.com/wiki/Heart_of_the_Underdog Underdog]] Exodia Deck that adds in a good number of banned cards, field-nukes, and stall, while Kaiba's lacks anything special beyond [[https://yugipedia.com/wiki/Ancient_Rules Ancient Rules]] and a nerfed [[https://yugipedia.com/wiki/Crush_Card_Virus Crush Card Virus]]. Unless Yugi bricks hard, you're not gonna finish this one.
* The Duel against Dartz (DLC or in Link Evolution), due to Yugi's Deck being a textbook example of AwesomeButImpractical: more than half of his monsters require tribute or, in the case of the [[https://yugipedia.com/wiki/Legendary_Knight Legendary Knight]]s have strict Special Summoning conditions, thereby putting you at enormous risk of bricking, and the few that can be summoned right away have such paltry attack that you'll most likely just Set them. Ironically, unlike his infamously broken anime Deck, here Dartz runs a BoringButPractical [[https://yugipedia.com/wiki/Beatdown beatdown]] Deck focusing on Summoning Normal Monsters with high ATK and powering them up with [[https://yugipedia.com/wiki/The_Seal_of_Orichalcos The Seal of Orichalcos]], with a few field nukes to throw at you should you get lucky enough to get the high ATK monsters out. In the anime Yugi could rely on the power of AssPull, but here, prepare to restart a lot.
* The second Duel against Revolver/Varis in the VRAINS campaign is about as one-sided as ''WesternAnimation/BambiMeetsGodzilla''. He plays a [[https://yugipedia.com/wiki/Rokket Rokket]] Deck with high swarming capability, with his monsters Special Summoning other Rokket monsters from his Deck when they're in the Graveyard and a Field Spell that allows him to gather pretty much as many Link Materials as he pleases every turn, on top of boosting the strength of his Rokket monsters. He also has five [[https://yugipedia.com/wiki/Mirror_Force "Mirror"]] Trap Cards that will destroy all of your monsters in Attack Position, and powerful Link monsters such as the [[https://yugipedia.com/wiki/Topologic Topologic]] monsters, who can clear your Main Monster Zone, banish your Spell/Trap Cards and inflict the ATK of your destroyed monster as effect damage, and the [[https://yugipedia.com/wiki/Borrel Borrel]] dragons, with whom he can steal your monsters. Meanwhile, you're stuck with a [[https://yugipedia.com/wiki/Cyberse Cyberse]] Deck that is seriously lacking in firepower and with no backrow removal and no field control, meaning you have to rely on your own Link Monsters, who are unlikely to last long against the constant barrage of high-ATK monsters he keeps throwing at you.
* The duel between Jaden and Axel Brodie can be ridiculous when using Jaden's story Deck. Axel uses what was pretty standard for the early days -- high- (1800-1900) ATK 4-star monsters along with a bunch of Spells and effects to destroy the opponent's monsters. Jaden's Deck, meanwhile, is split thematically between his [[https://yugipedia.com/wiki/HERO HERO]]es and [[https://yugipedia.com/wiki/Neo-Spacian Neo-Spacian]]s without committing fully to either. He doesn't have [[https://yugipedia.com/wiki/Elemental_HERO_Clayman Clayman]] (DEF 2000) to serve as a low level wall, and the only fusion card he has in the Deck is the basic [[https://yugipedia.com/wiki/Polymerization Polymerization]]. This means the player has to devote multiple-card combos to bring out a Fusion Monster or [[https://yugipedia.com/wiki/Elemental_HERO_Neos Neos]], only for it to be destroyed by an enemy removal effect. It's somewhat implied that you are supposed to use [[https://yugipedia.com/wiki/De-Fusion De-Fusion]] to bypass destruction, but that requires you to have that card in hand as well. On top of that, the only removal available for Axel's various continuous Spell and Trap cards is one of the Fusion Monsters.
* The first Reverse Duel between Jack Atlas and Yusei is also very annoying to beat with the story Deck, as you have no way to destroy Yusei's [[https://yugipedia.com/wiki/Scrap-Iron_Scarecrow Scrap-Iron Scarecrow]]s (and thus you'll spend most of the Duel locked down unable to do much of anything), and he'll steal your Synchro Summons at every opportunity. The only way to reasonably win is to hope that he doesn't draw and set too many Scarecrows too early, and to swarm him with as many basic monsters as possible before you get overwhelmed.
* The Yuma V.S. Don Thousand duel is this if you're playing as Don Thousand. Since his [[https://yugipedia.com/wiki/Numeron Numeron]] monsters weren't in the game when this was released, his Deck is a mishmash of the Barian Emperors' decks, while Yuma uses a [[https://yugipedia.com/wiki/Number_39:_Utopia_(archetype) Utopia Turbo]] Deck. Most of the time, you're struggling to get an Xyz Monster on the field, and even if you do, don't expect it to last long.
* The duel between Tea and Mai is probably the first big difficulty spike in the campaign if you're using the Story decks. Tea has a deck of very weak monsters whose stats max out at about the same amount that most of Mai's monsters start at, supplemented with lots of Equip Spells to even the playing field. However, Mai has multiple copies of [[https://yugipedia.com/wiki/De-Spell De-Spell]] to target your Equip Spells with, and even a copy of [[https://yugipedia.com/wiki/Harpie%27s_Feather_Duster Harpie's Feather Duster]] to for mass Spell destruction, and unlike the anime, Mai is NOT afraid to use them. You're supposed to bait out Mai's anti-Spell cards before making a big push, but Mai also has a very consistent deck with modern Harpie support that can search out and summon her big monsters very quickly, so you need to go on the offensive as soon as you can to avoid being run over. It's at best a nail biting balancing act and at worst a frustrating lucksack-fest.
[[/folder]]

[[folder:''Master Duel'']]
The Solo campaign of ''VideoGame/YuGiOhMasterDuel'' introduces you to the backstory of several of the game's archetypes and you get to play loaner Decks that show off their mechanics and possible hybrids that can be built with them. However, several Duels give you a terrible loaner that is outmatched by the opponent's far better Deck, leading to these games being decided on whether the opponent got an unplayable hand and yours functional. Several outstanding examples were bad enough that the deck lists were changed to give a better experience.
* Even before the story gates, the [[https://yugipedia.com/wiki/Solo_Mode#Duel_Strategy_2 Duel Strategy 2 Gate]] has one extremely difficult battle. On the second-to-last practice duel, your loaner Cyberse deck is intended to teach you how to summon more Link Monsters via pointing, and while it does that well enough, the ability for the deck to handle an actual duel is lacking, which is best seen by the [[https://yugipedia.com/wiki/Gouki Gouki]] deck you're up against in this fight. The Gouki deck is extremely optimized around its archetype, while your generalist Cyberse deck just isn't, to the point where the fight almost feels like it comes down to RNG - your best hope is to get [[https://yugipedia.com/wiki/Accesscode_Talker Accesscode Talker]] out using a Link-3 as material and pray that either you draw a second [[https://yugipedia.com/wiki/Cynet_Crosswipe Cynet Crosswipe]] to deal with his second big Gouki boss monster, since you have to use the one guaranteed in your starting hand almost immediately to take out his first one, and that he doesn't summon a [[https://yugipedia.com/wiki/Gouki_Bearhug Gouki Bearhug]] to neuter your Talker. Again, this is a ''tutorial'' fight.
* The [[https://yugipedia.com/wiki/The_Warriors_of_the_Six_Elemental_Lords Elementsaber Gate]] demonstrates an archetype designed to synergize off the wide variety of Attributes in the archetype and occasionally using their Attribute-changing abilities to support an [[https://yugipedia.com/wiki/Elemental_Lord Elemental Lord]], but its Duels force you into a loaner that mashes the archetype with a different mono-Attribute one. The WIND-vs.-EARTH Duel sucks the most since you're running a hybrid with a mediocre [[https://yugipedia.com/wiki/Mist_Valley Mist Valley]] selection that struggles to get a good field presence, while the opponent's EARTH Deck has a lot of recruiters that keep calling in other monsters from the Deck, meaning you'll get quickly overrun. This Duel was rebalanced a bit by swapping a few of the Mist Valley components with straight-up better cards that stay on the field.
* The [[https://yugipedia.com/wiki/Ruin_and_Demise_(Gate) Ruin and Demise Gate]] focuses on [[https://yugipedia.com/wiki/Ruin,_Queen_of_Oblivion Ruin]] and [[https://yugipedia.com/wiki/Demise,_King_of_Armageddon Demise]], Ritual Monsters that can be Summoned off the same Ritual Spell. After the initial practice match, you get given loaners that give you one of the duo while the opponent's Deck focuses on the other. The final Duel introduces hybrids alongside one of the two. Your Loaner is a Ruin Deck with a side of [[https://yugipedia.com/wiki/Cyber_Angel Cyber Angel]] Ritual support with a miserably inconsistent monster selection, while the opponent runs a well-tuned Demise OTK Deck featuring [[https://yugipedia.com/wiki/Advanced_Ritual_Art Advanced Ritual Art]] to summon its boss monsters without exhausting its hand. This is one of the Duels that got rebalanced, giving your Deck a better focus on Summoning Ruin and adding a few staple cards to help stabilize if things go south.
* The final Duel of the [[https://yugipedia.com/wiki/The_Mystery_of_the_Megalith Megalith Gate]] gave you a hybrid Deck with "[[https://yugipedia.com/wiki/Adamancipator Adamancipators]]", and the opponent gets a hybrid using "[[https://yugipedia.com/wiki/Fossil Fossils]]". The big difference between the Decks: Your opponent had 2 copies of [[https://yugipedia.com/wiki/Block_Dragon Block Dragon]], an irritatingly tough monster that could replenish the hand with Rocks when it goes down, and you have none, even though your hybrid would greatly appreciate it. Also, your supplementary cards struggled to beat past the opponent's board. When this Duel was rebalanced, your Loaner gained a Block Dragon to use for yourself and gained additional staples like Raigeki, Mirror Force and Bottomless Trap Hole to break the opponet's board better, while Block Dragon was completely removed from the opponent's list.
* The final duel of the [[https://yugipedia.com/wiki/The_Pyroxene_Warriors Gem-Knight Gate]] is pure hell with the Loaner Deck. The AI has a streamlined Gem-Knight Deck supplemented with [[https://yugipedia.com/wiki/Rescue_Rabbit Rescue Rabbit]] to spam out Fusions while also having access to hand traps and GY effects to disrupt your plays. The loaner, meanwhile, is a Gem-Knight/[[https://yugipedia.com/wiki/Constellar Constellar]] hybrid that has so little synergy that it more often than not sabotages itself, worse Gem-Knight monsters than your opponent has access to, and no hand traps. The Duel was rebalanced by giving both Decks a more even selection of Fusion Monsters, swapped the opponent's hand-traps for a weaker monster selection, added more variety to the opponent's Normal Monsters to make Rescue Rabbit much less impactful, and transferred the [[https://yugipedia.com/wiki/Lightning_Storm Lightning Storms]] from the opponent's Deck to your Loaner.
* The final Duel of the [[https://yugipedia.com/wiki/Digital_Bugs_in_Cyberspace Digital Bug Gate]] is also horrendous. The AI Deck in this case has the [[https://yugipedia.com/wiki/Digital_Bug Digital Bug]] strategy supplemented with an [[https://yugipedia.com/wiki/Inzektor Inzektor]] Deck and powerful staples like [[https://yugipedia.com/wiki/Maxx_%22C%22 Maxx "C"]], [[https://yugipedia.com/wiki/Infinite_Impermanence Infinite Impermanence]] and [[https://yugipedia.com/wiki/Lightning_Storm Lightning Storm]], plus other staples like [[https://yugipedia.com/wiki/Raigeki Raigeki]], [[https://yugipedia.com/wiki/Monster_Reborn Monster Reborn]], and [[https://yugipedia.com/wiki/Foolish_Burial Foolish Burial]]. Your loaner is a hybrid Digital Bug/[[https://yugipedia.com/wiki/Kaiju Kaiju]] deck that tends to sabotage itself, mainly due to the Kaiju Spells / Traps that tend to help your opponent more than it helps you (except [[https://yugipedia.com/wiki/Interrupted_Kaiju_Slumber Interrupted Kaiju Slumber]], which is the only good Kaiju Spell / Trap card you get), and fewer staples than your opponent has. Your Deck is also given [[https://yugipedia.com/wiki/Owner%27s_Seal Owner's Seal]] for your Kaiju monsters, if you can ''draw'' it, of course. As above, winning is mostly luck of the draw, because in almost every other instance, your opponent will summon a powerful field filled with a strongly-equipped Inzektor monster, and Digital Bug Xyz monsters, including [[https://yugipedia.com/wiki/Digital_Bug_Rhinosebus Rhinosebus]] (can destroy cards the opponent controls) and [[https://yugipedia.com/wiki/Digital_Bug_Corebage Corebage]] (can send a Defense Position monster you control back to your Deck). Coupled with the extra effects of the Digital Bug monsters, it's a recipe for disaster.
* The [[https://yugipedia.com/wiki/The_Legend_of_the_Star_Heroes World Legacy Gate]] is one of the longest Gates in the game, and has plenty of opportunities for painful duels:
** The final Duel of the second part uses a loaner which is built around the protagonists of the [[https://yugipedia.com/wiki/World_Chalice World Chalice]] storyline with an incoherent array of support and ''no Extra Deck''. While this provides an excellent example of GameplayAndStoryIntegration (as [[https://yugipedia.com/wiki/Knightmare_Corruptor_Iblee Iblee]] took away the protagonist's World Chalice powers, thus by extension their Link Monster form) and you ''are'' given some tools to handle the challenge, at the end of the day your ''Normal Monsters'' are largely inadequate to stand up against the [[https://yugipedia.com/wiki/Mekk-Knight Mekk-Knight]] and [[https://yugipedia.com/wiki/Knightmare Knightmare]] monsters that the opponent is throwing at you, including Knightmare Mermaid and Knightmare Goblin, [[TheComputerIsACheatingBastard both of which are banned cards.]]
** The third part of this Gate has an Orcust bonus Duel where you and the computer are using Orcust hybrids with DARK Machines. The opponent's Deck has a focused Orcust and World Legacy base supplanted with some decent generic DARK Machine support, but you are given a [[https://yugipedia.com/wiki/Jinzo_(archetype) Jinzo]] hybrid that doesn't play well alongside your Orcust cards. More than half the time your opponent will be consistently going through its combos while you are stuck with a largely unplayable hand.
* The [[https://yugipedia.com/wiki/SP_Deck_Challenge SP Deck Challenges]] replicate climactic matches from the anime, but both you and the AI get to use modern cards to supplant the archetype you're running so that you get a different experience from ''VideoGame/YuGiOhLegacyOfTheDuelist''. However, several loaner Decks are infamously prone to bricking, due in large part to said modernization being very inconsistent--sometimes you end up with cases where the opponent has a ton of badass retrains and consistency boosters, and you're stuck with three copies of dated vanillas:
** The Joey vs. Bandit Keith Duel is exceptionally bad. Your loaner, representing Joey's Deck, is a hopeless mishmash of cards with no clear common synergy, on top of some ''very'' outdated monsters (including running the vanilla versions of [[https://yugipedia.com/wiki/Black_Skull_Dragon Black Skull Dragon]] and [[https://yugipedia.com/wiki/Meteor_Black_Dragon Meteor Black Dragon]] but ''not [[https://yugipedia.com/wiki/Archfiend_Black_Skull_Dragon their]] [[https://yugipedia.com/wiki/Meteor_Black_Comet_Dragon retrains]]''). The opponent, on the other hand, is running [[https://yugipedia.com/wiki/Barrel_Dragon Barrel Dragon]]s with the full suite of modern support and has plenty of removal to gun down your setup.
** The Yugi vs. Mai Duel gives you a loaner built around [[https://yugipedia.com/wiki/Black_Luster_Soldier Black Luster Soldier]] and [[https://yugipedia.com/wiki/Black_Luster_Soldier_(archetype) its Ritual variants]], and as you'd expect from a Deck running Rituals without the plethora of Ritual support, you get an unplayable hand half the time, while Mai has the full suite of [[https://yugipedia.com/wiki/Harpie Harpie]] support and can tear apart your backrow, which is your only means of interaction on her turn.
** The Yugi vs. Joey Duel gives you a loaner built around summoning the [[https://yugipedia.com/wiki/Egyptian_God Egyptian God]]s, but you have very few monsters you can Normal Summon to even get to the God Cards. Joey, meanwhile, has upgraded from his poor showing in the earlier SP Duel and is running a full suite of [[https://yugipedia.com/wiki/Red-Eyes Red-Eyes]] cards. Summoning [[https://yugipedia.com/wiki/The_Winged_Dragon_of_Ra The Winged Dragon of Ra]] is pretty much a death sentence for you because it forces you to pay LP until you have 100 left... while Joey's Red-Eyes build has a lot of ways to inflict effect damage.
** The final Duel of the first SP Challenge replicates the Ceremonial Duel from the end of the series where Yugi faces Atem. However, what should be an awesome fight is bogged down by the fact that you're stuck with [[https://yugipedia.com/wiki/Gadget Gadget]]s and some subpar support with the [[https://yugipedia.com/wiki/Silent_Swordsman_(archetype) Silent Swordsman]]/[[https://yugipedia.com/wiki/Silent_Magician_(archetype) Magician]] ensemble bricking your hands more often than not while Atem brings a fairly potent [[https://yugipedia.com/wiki/Dark_Magician_(archetype) Dark Magician]] Deck. If he gets [[https://yugipedia.com/wiki/Ebon_Illusion_Magician Ebon Illusion Magician]] out, you might as well scoop right there as the Deck you're given basically has no out to it. And given his Deck has multiple ways to get Level 7 Spellcasters on the board, like [[https://yugipedia.com/wiki/Palladium_Oracle_Mahad Palladium Oracle Mahad]] and [[https://yugipedia.com/wiki/Magician_Navigation Magician Navigation]], Atem can bring out Ebon Illusion Magician frustratingly easily. It doesn't help that this loaner match also has a very tempting prize of 200 gems for completing it.
** [[https://yugipedia.com/wiki/SP_Deck_Challenge_2 The second SP Gate]] lets you relive climactic matches from ''Anime/YuGiOhGX'', but since Jaden did most of the heavy lifting in the series, most of the loaners are basically the same HERO Deck with minor tweaks to reflect what Jaden used at the time. While you do get a lot of situational and outdated cards, you can generally rely on manga HERO cards and modern powerhouses like Sunrise and Grandmerge to see things through, even as your loaner lists lose consistency. However, the sixth Duel, representing Jaden's and Jesse's duel against a Yubel-possessed Marcel, is a completely different story. Your Loaner is an inconsistent Neos and Crystal Beast hybrid that has little common synergy and not enough copies of the modern cards to help make it work, while the opponent has a streamlined Sacred Beasts deck using three copies of all its modern support to push out its powerhouses. If the opponent gets to Summon any of the Sacred Beasts (that easily happens by turn 3), you're better off resetting.
* The [[https://yugipedia.com/wiki/The_Fairies_who_Paint_the_Weather Weather Solo Gate]]'s final Duel gives you access to the [[https://yugipedia.com/wiki/Nemeses Nemeses]] archetype in your loaner. In theory, this combination should have some synergy, as the Weather Painters banish themselves from the field to activate effects and the Nemeses monsters can Special Summon themselves from the hand by returning banished monsters to the Deck. In practice, however, the two archetypes actively conflict with each other, as the Weather strategy relies on having your banished Weather Painters return to the field during the Standby Phase to build up card advantage, something the Nemeses cards prevent you from doing. Your opponent, on the other hand, has a far better combination of Weather and [[https://yugipedia.com/wiki/True_Draco True Draco]], an archetype that takes full advantage of the numerous Weather Continuous Spells/Traps as Tribute Material for their high-ATK monsters.
* The [[https://yugipedia.com/wiki/The_Danger_Files Danger! Solo Gate]] has the "Danger! Lair" Duel. Your opponent is equipped with a Danger! stun Deck that uses [[https://yugipedia.com/wiki/Lair_of_Darkness Lair of Darkness]], a card that enables your opponent to Tribute monsters ''you'' control for their card effects. Meanwhile, you get a "Danger!" Deck mashed together with ''[[https://yugipedia.com/wiki/Kuriboh_(archetype) Kuriboh]]'', of all archetypes, all of which are essentially bricks. If your opponent opens any form of backrow or you draw into more than 3 Kuribohs you might as well reset on the spot, since the Kuriboh cards contribute nothing to your overall game plan and your opponent can just as easily delete cards from your field in a heartbeat.
* The [[https://yugipedia.com/wiki/Worshippers_of_the_Sacred_Phoenix Nephthys Gate]]'s final Duel gives you a hybrid consisting of half-baked [[https://yugipedia.com/wiki/Charmer "Charmer"]] support and some "Nephthys" cards. The consistency kit of previous duels that allowed you to consistently summon [[https://yugipedia.com/wiki/Conductor_of_Nephthys Conductor of Nephthys]] is gone, replaced with cards that do very little [[https://yugipedia.com/wiki/Unpossessed because they need you]] [[https://yugipedia.com/wiki/Possessed_Partnerships to control multiple attributes]] while your entire Main Deck is filled with WIND monsters, or cards that are good [[https://yugipedia.com/wiki/Grand_Spiritual_Art_-_Ichirin but lack]] [[https://yugipedia.com/wiki/Awakening_of_the_Possessed any kind of synergy]] with your "Nephthys" monsters. Meanwhile, your opponent has the entire array of [[https://yugipedia.com/wiki/Impcantation Impcantation]] support to facilitate multiple Ritual summons, multiple Pot cards to increase their consistency, and [[https://yugipedia.com/wiki/Sacred_Phoenix_of_Nephthys Sacred Phoenix of Nephthys]] (which, incidentally, your own deck lacks) to make short work of the backrow that is essential to the "Charmer" part of your deck. The loaner was later rebalanced by removing copies of the most situational "Charmer" cards, increasing the copies of their better support, and adding back the 3 copies of "Pre-Preparation of Rites".

[[/folder]]

[[folder:Unsorted/Misc.]]
* In ''VideoGame/YuGiOhNightmareTroubadour'':
** The game presents several tough opponents, but the hardest fight has to be the boss rush of Big 5, Noah, and Gozaburo:
*** Big 5 uses a Deck centered around [[https://yugipedia.com/wiki/Satellite_Cannon Satellite Cannon]], which is an annoying one-Tribute monster that cannot be destroyed in battle by any monster Level 7 or lower, and increases its ATK by 1000 every turn, which then drops back to 0 once it attacks. Big 5 will keep Satellite Cannon in Defense Position until it has several thousand ATK, and then he will kill you with battle damage.
*** Noah plays many powerful Fairies and backs them up with [[https://yugipedia.com/wiki/The_Sanctuary_in_the_Sky The Sanctuary in the Sky]], which eliminates all battle damage with battles attacking a Fairy-type monster. The major problem with Noah, though, is his ritual monster [[https://yugipedia.com/wiki/Shinato,_King_of_a_Higher_Plane Shinato, King of a Higher Plane]]. This guy has a whopping 3300 ATK/3000 DEF. So you'll just Set monsters until you get something to kill him? When it destroys a Defense Position monster, you take effect damage equal to that monster's ATK! Good luck destroying it.
*** Gozaburo runs an [[https://yugipedia.com/wiki/Exodia_Necross Exodia Necross]] Deck with weak monsters and suffers from poor AI, but his duel is timed so you instantly lose in 20 turns, meaning you must defeat him in 10 turns or less. He stalls like there is no tomorrow, and if he uses a [[https://yugipedia.com/wiki/Scapegoat Scapegoat]] card, you can lose anywhere from 1 to 4 turns.
** The final possessed Joey fight is hard because you can't win or lose; you must force a DRAW using [[https://yugipedia.com/wiki/Ring_of_Destruction Ring of Destruction]], which had yet to be nerfed, or [[https://yugipedia.com/wiki/Self-Destruct_Button Self-Destruct Button]], (or [[https://yugipedia.com/wiki/Tremendous_Fire Tremendous Fire]], though the game does not tell you that) all very situational cards.
** Ryou Bakura is very tough [[EarlyBirdBoss early on]], as he uses an [[https://yugipedia.com/wiki/Ectoplasmer Ectoplasmer]]/[[https://yugipedia.com/wiki/Call_of_the_Mummy Call of the Mummy]] combo that lets him tribute monsters to damage you directly while keeping a fresh supply of monsters on his field to attack you with, and you can't fight back since you must also tribute monsters to Ectoplasmer. His second Deck uses [[https://yugipedia.com/wiki/Vampire_Lord Vampire Lord]] and [[https://yugipedia.com/wiki/Patrician_of_Darkness Patrician of Darkness]], who can respectively remove monsters from your Deck and control which of his monsters you attack.
** Yami Bakura. In his first Deck, he uses a [[https://yugipedia.com/wiki/Destiny_Board Destiny Board]] combo, which results in an instant loss after five turns if you can't destroy it. His second deck uses [[https://yugipedia.com/wiki/Dark_Necrofear Dark Necrofear]], a very annoying monster who's Summoned by tributing three Fiends in the Graveyard. Her effect is that, once destroyed, through battle ''or'' card effect, she controls one monster you control. And he has more than one.
** Yami Marik is a difficult fight on his own but is made even more difficult with how you must win using your Egyptian God Card—who is vulnerable to traps like Mirror Force.
* ''Videogame/YuGiOhGXSpiritCaller'':
** Hell Kaiser Ryo/[[DubNameChange Dark Zane]]. Matches with him go one of two ways: you steamrolling him, or him steamrolling you with his [[https://yugipedia.com/wiki/Chimeratech_OTK Chimeratech OTK]] Deck. You can lose this easily if you get a bad hand. Worse, this is a Shadow Duel and the Duelist can't be registered, so you can stumble onto him while spirit hunting in the postgame. Lose to him, and it's game over.
** ''Titan''. He uses a Deck the boils down to the RandomNumberGod on steroids. All his monsters have effects that can negate your monster effects and destroy them, or destroy any monsters that attack his. While it's ''supposed'' to be a double-edged sword for him, Titan [[TheComputerIsACheatingBastard has an uncanny ability to get nearly all of his rolls in his favor]], resulting in ''any'' of your attempts to gain an edge against him falling flat on your face. Really, no matter ''what'' Deck you're playing, duels against him boil down to [[LuckBasedMission how generous the RNG feels like being]], and more often than not, no matter how much you prepare for him, he ''will'' get his RNG-based shenanigans going no matter what.
** Kagemaru. You must duel him three times in a SequentialBoss battle, and he'll use a different [[https://yugipedia.com/wiki/Sacred_Beast Sacred Beast]]-focused Deck in each Duel. All three of his Decks are well built to summon each Sacred Beast they are themed around, and come with powerful support and destruction cards for tearing apart his opponents. Worse, you can only progress in the next stage of the boss fight by defeating him ''after'' he summons a Sacred Beast, so it's possible to lose while you're stalling for him to play one.
* In ''Duel Transer'':
** Odin's first encounter in story mode can become a major roadblock. He uses a WATER Deck that excels at both beatdown and returning monsters to the hand. Chances are, by now, the player has built a Deck that is reliant on Synchro Monsters, which are instead returned to the Extra Deck instead of the hand. The numerous powerup effects of [[https://yugipedia.com/wiki/Spined_Gillman Spined Gillman]] and [[https://yugipedia.com/wiki/Umiiruka Umiiruka]] can make the Deck incredibly challenging to face. If that isn't enough, Odin's Extra Deck includes the un-nerfed [[https://yugipedia.com/wiki/Brionac,_Dragon_of_the_Ice_Barrier Brionac]] and [[https://yugipedia.com/wiki/Trishula,_Dragon_of_the_Ice_Barrier Trishula]], who were both Forbidden following the production of this game until they got nerfed. Even worse, usually his non-Synchro Monsters will be powered up enough to force the player's Synchro Monsters into play, where the bounce effect can come into play. Thankfully, by the time the player has to face this boss again, who is now more powerful, the player will have access to more cards, which will make this less of a challenge.
** Aside from Odin, plenty of opponents can become troublesome. If you're not prepared to remove Yusei's defensive Traps, he will have enough time to summon a strong monster and wipe the floor with yours. Crow can also be a problem when you don't have ways to prevent his swarming of the field. Also, among the 150+ Transcenders in this game, about ten of them are insanely difficult to beat, like the one using a combination of Final Countdown, cards that protect its Life Points and destroy your Spells and Traps easily, and [[https://yugipedia.com/wiki/Fiber_Jar Fiber Jar]]. (Take note that the bonus building, Niflheimr, only has Transcenders... and most of them [[TheComputerIsACheatingBastard use multiple copies of Limited and Semi-Limited cards]]. The aforementioned Transcender? He has three copies of Fiber Jar. He just plays Final Countdown, resets the match with Fiber Jar, and before you know it, the 20 turns are over. Enjoy!
* ''VideoGame/YuGiOhCapsuleMonsterColiseum'' has several tough opponents, particularly in the later stages of the game.
** Seto Kaiba's first stage is very troublesome because it has many areas where you cannot move, but his monsters can get around it and attack you easily.
** Marik's stage is a box of squares that power up certain attributes, forcing you to pick battles carefully. His strongest monster is [[https://yugipedia.com/wiki/Zoa_(Capsule_Monster_Coliseum) Zoa]], which has a huge amount of attack strength that's boosted even more if he lands on a dark space. If you don't take Zoa out immediately, it can defeat weaker monsters with one hit.
** Yami Marik's second stage takes place on a volcano that erupts. Any monster standing in the lava gets a huge boost to attack, but takes damage if they're not Fire-type. Most of his monsters are Fire-type, and many have long attack ranges. If you're not careful, he can defeat your monsters with one blow each.
[[/folder]]

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