"When I rob you from now on, it's just my way of saying 'Charon, I would like to battle you to the death right now for a quick change of pace'."
— Zagreus, Hades
Bosses are big, scary, and typically await you at the end of each level. Gameplay wise, they serve as the ultimate challenge of skills the player has learned so far. In the story they are typically villains or other opponents that antagonize The Hero is a specific story segment.
But not all bosses are like this; some you just don't get to fight normally. Sometimes the developers want the player to have something else to do and challenge themselves with extra fights. It can be a good opportunity to add some Worldbuilding with side-quests and problems irrelevant to the Myth Arc. The player doesn't have to solve every trouble the townsfolk have, but it's often encouraged. The reward can be just extra loot to help yourself (especially in Forced Level-Grinding), a Disc-One Nuke, or an unlockable secret. Unlocking such an encounter (either directly or indirectly via provided a required item) is a common Revisit Reward.
Subtropes:
- Open-Ended Boss Battle: A boss that is a mandatory encounter, but the player can still lose to them and carry on with the game.
- Route Boss: A boss that is only encountered in one particular story branch and not the other.
- Skippable Boss: A boss that is encountered, but the fight can be aborted depending on player choices. A Pacifist Run requires you to flee from boss encounters if possible.
- Superboss: A boss that is designed to be Nintendo Hard and tougher than any other boss. May give a Disc-One Nuke or Bragging Rights Reward on defeat, turning the Final Boss into an Anti-Climax Boss.
- True Final Boss: Final Bosses that are locked out until the player meets certain criteria. Usually required for a Golden Ending or 100% Completion.
Examples:
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Action-Adventure Games
- ANNO: Mutationem: There are three optional boss fights at Harbor Town's fighting arena; Pyrofist, Eric Marcom, and Tai Long. Each of them are not required to be fought as part of the main story, but choosing to fight them awards much Grombitz and defeating all of them grants a gold trophy as an award.
- Aquaria has a number of optional bosses, but many consider Simon Says to be the most interesting. He's well-hidden, and you don't actually fight him — instead you play, well, Simon Says, with a very useful third cooking slot as your reward for playing well.
- Castlevania series:
- Castlevania 64 has the demon Renon, who's been running the Dungeon Shop throughout the game. If you haven't used his services too much, he appears near the end of the game to say he's leaving for better business opportunities elsewhere. But if you've spent more than 30,000 gold at his shop, instead he invokes the fine print in the "contract" on the scrolls you've been summoning him with to try to claim the player character's soul, at which point he turns into his true form and attacks.
- Castlevania: Order of Ecclesia gave you the option to fight the Chinese vampire, Jiang Shi, in the Large Cavern bonus dungeon. He's not very hard, though, seeing as how proper use of Melio Scutum and any slashing Glyph would easily reduce his 6000+ HP down to nothing. Though this boss is interesting in the fact that when he dies, a seal is placed on his face, but if you break it off with an attack, he comes back to life, allowing you to fight him again as many times as you want. Not worth the attribute points though (30, 60, or 120).
- The Whip's Memory, an image of Richter Belmont in Castlevania: Portrait of Ruin, is part of a ritual to unlock the true power of a weakened Vampire Killer whip. Unlike the rest of the game, you can only battle this boss with Jonathan. Thankfully, "dying" in this battle just boots you out of the battle with full HP and MP instead of yielding a Game Over.
- Hollow Knight: Many bosses are found off the beaten path and aren't required to beat the game. They are, however, required if you want to fill out the Hunter's journal and get associated items they guard for 100% completion.
- Hollow Knight: Silksong follows the above example, but also adds some bosses that can only be found and fought if you accept Grand Hunt-type quests.
- Illusion of Gaia has Solid Arm, a boss originally from the first game in the series, Soul Blazer, who's only fightable if you collect all fifty Red Jewels.
- Ittle Dew 1 has one at the end of the Master Cave. Oddly, it's the one boss you beat through brute force rather than some kind of puzzle.
- The Legend of Zelda:
- The Legend of Zelda: Link's Awakening: The Updated Re-release of the game for Game Boy Color featured a Bonus Dungeon based on color, designed entirely to show off the capabilities of the Game Boy Color. The boss of the dungeon isn't more difficult than the other bosses, but even once you find the entrance to the dungeon you can only actually enter it if you know the color of the stalfos' clothes at the entrance. There are also a number of color-based puzzles that would be frustratingly difficult if you managed to get in anyway while playing on an original Game Boy.
- The Legend of Zelda: Breath of the Wild: Technically speaking, all the bosses, with the exception of Calamity Ganon and the four Blight Ganons, are optional to beat the game (this is because, if you skip freeing the Divine Beasts, the game forces you to fight the Blights you didn't encounter regardless in Hyrule Castle in a Boss Bonanza before the Final Boss). The game's direct sequel Tears of the Kingdom follows a similar structure.
- The Legend of Zelda: Echoes of Wisdom: Four different unique bosses can be found as part of the games many sidequests (two of which are fought multiple times), a Lanmola, Smog, Barinade, and a Volcanic Talus. Each of them rewards Zelda a Piece of Heart upon being defeated.
- After fully explorable hub words were introduced to the LEGO Adaptation Game series, many of them have included various boss fights that aren't necessary to beat to complete the story, but like everything else are needed for 100% Completion.
- Nine Sols: Celestial Sentinels are scattered around New Kunlun and act as souped up Mini-Boss versions of common enemies. They don't bear any weight to the plot and can be avoided (even if you happen to accidentally run into them), but defeating them yields various items and a lot of experience, plus tracking all of them down is required for an achievement.
- Sekiro: Shadows Die Twice:
- The Demon of Hatred does not need to be fought to complete the game, and the player has to go out of their way to even find it. Though beating it does net the player 2 Lapis Lazuli, which are needed to upgrade to the final tier of prosthetic upgrades.
- The Gauntlets of Strength adds 3 extra boss fights against powered-up versions of 3 of the games bosses, known as Inner Isshin, Inner Genichiro, and Inner Father. None of these are required to be fought to beat the game, since, well, the player can't even access the Gauntlets of Strength until after they've already beaten the game.
- Super Gear Quest: As Starter makes his way up Mt. Mokula, he repeatedly hears voices from a random assortment of characters telling him to follow them. Eventually, the voices will attempt to lead him away from where he's supposed to be going. If he decides to continue following them, despite being warned not to do so, he will end up finding himself face to face with a Khraosis Entity known as Dimula. Considering that the only other Khraosis Entity he fights in the game is the True Final Boss, he's in for a difficult fight.
- Terraria features several bosses that can be ignored, but drop powerful items that can help the player beat the game. One notable example is Duke Fishron, a pig-dragon-fish that must be fished out of the ocean using a rare mushroom worm as bait.
- Tribal Hunter has four optional bosses spread out over the latter half of the game: Laura, who you find at the end of a passage way in the Jungle filled with ko'd pirates, Wave, who you meet in the Hive in a not so hidden passage that ends in a room with him and a bunch of boxes and chests, The Queen Bee, whose arena is to the right of the exit to the mountain top, and The Alpha, whose arena is in the mountain top area, its entrance in the same room as where you first find the wolf enemies.
Action Games
- Cuphead:
- Performing specific actions against certain bosses heavily alters the fight, usually skipping or cutting short a phase of the fight - at the cost of adding additional enemies in later phases.
- The DLC adds a secret boss, found by interacting with specific tombstones, and then examining the strange light while having the Broken Relic charm. Defeating the boss "upgrades" the charm into the Cursed Relic, which turns you into a One-Hit-Point Wonder and forces you to use random weapons. Defeating enough bosses (a maximum of 8 and minimum of 4) with the Cursed Relic equipped turns it into the Divine Relic, which gives you the positive effects of every charm you own at the same time and lets you switch freely between all of your weapons.
- Shrek 2 (Activision): The Prison Break level features a boss fight against a troll. The troll can be skipped by rolling a metal ball into a nearby gate, which opens up an alternate route that takes you past the troll's arena.
Beat 'em Ups
- Via Asura's Wrath DLC, two optional bosses that have nothing to do with the main game story are Ryu and Akuma, who become Evil Ryu and Oni respectively.
- The Red Dragon features as an optional boss in both of the Dungeons & Dragons Beat Em Ups.
- Like a Dragon: Virtually every main game in the series has a coliseum where you can fight various enemies that you can't fight otherwise, including members of the aformentioned Amon clan, other protagonists, the masters who trained you, bears and tigers, and real-life professional wrestlers.
- No More Heroes 2: Desperate Struggle has Kimmy, a school girl with an unhealthy obsession over Travis. You only fight her if you don't go back to the Motel between fights with Charlie and Matt, making her the only assassin in the series who's optional.
- In River City Ransom, Benny and Clyde are the only bosses that you don't have to defeat in order to access River City High School. Once inside, you can also skip Tex as well, since only Otis has to be defeated in order to fight the Dragon Twins, and then Slick, who is actually Simon.
Card Games
- Yu-Gi-Oh!:
- Yu-Gi-Oh! Reshef of Destruction:
- At the start of the game, before you board the Duel Express, you can visit KaibaCorp to find Rebecca trying to get back at Kaiba for tearing up her grandfather's copy of Blue-Eyes. Kaiba has no patience for this but lets you challenge her instead. However, because you've just started and your deck flat-out sucks, you'll be struggling due to lack of resources.
- A sidequest, briefly available after restoring Obelisk, leads you to dueling the Big Five as part of a stage performance.
- If you visit Italy after Canada's been made available to you, you'll get to rematch Jean-Claude Magnum, who has a better deck than the first time. In this same time frame, you can also find Tea worrying about fortune-telling, and have to fend off Johnny Steps and Crump back-to-back.
- In Yu-Gi-Oh! GX Duel Academy, there is an event where you can challenge and duel Pharaoh, Dr. Banner's cat. To do so, you must be a member of the Slifer dorm, and have defeated Jaden, Syrus, Chumley and Banner three times each. If you then talk to Banner on a Saturday, you can duel Pharaoh, and get a card afterwards. (Panther Warrior for winning, Bone Mouse for losing, and Outstanding Dog Marron for drawing).
- Yu-Gi-Oh! Reshef of Destruction:
- Shambles from Exlix is a Korean post-apocalypse story-driven game similar to Slay the Spire, one of the most expensive unlockabke characters is the boxer Michael. In his story subplot, he has a chance to fight to become the Underground Tournament champion. Unfortunately the reigning champ is something of a Puzzle Boss who can outlast normal brute force attacks with his Damage-Sponge Boss levels of health combined with extreme damage, vampiric health restore and the power to reduce the damage you can inflict on him. The way to beat him is either master Michael's unique boxing combo ability to do a near-endless combo or else hit him with a lot of debunks that weakened the champ and also cause damage over time. A debut purifying item will also greatly help you.
Fighting Games
- If you manage to beat The King of Fighters: Maximum Impact Regulation A without using any continues and with enough Super Finishes, you'll get to fight Makoto Mizoguchi of Fighter's History fame.
- Tekken:
- Tekken 2 has Roger the kangaroo, who appears in the fourth stage if you beat the third stage with low enough health to get a "Great!" from the announcer. Beating him and the rest of Arcade Mode will unlock him and his Moveset Clone Alex, who is a dinosaur.
- In Tekken 6, there's Nancy. She's one of several giant robots developed by the Mishima Zaibatsu, perhaps to combat Azazel, who is finally free after 10,000 years. Her appearance is sort of a Big-Lipped Alligator Moment in that you get rewards for beating her but if you don't, it has absolutely no bearing on your progress and you don't get the option of fighting her again without restarting. She is playable, but only in one level of Scenario Campaign.
- Virtual-ON:
- In the first game, if you win all your battles by Time Over, you'll get a Warning message and then enter a special battle with Jaguarandi, a mutated version of Raiden that varies each time you fight it. When you first fight it, it's about the size of a Raiden or a Belgdor, and its color is the opposite color of your mech. If you continue against it, it changes to a miniature toy-sized version that is colored purple, and its armor weakens severely (so much so that a close range attack from Apharmd will kill it instantly), and if you continue again, it can be killed in 3 hits by Temjin's Beam Rifle! In the Japan-only PS2 version, if you beat all 8 virtuaroids in under 30 seconds, you will hear a special chime and fight the original Fei-Yen instead of Z-Gradt. This version of Fei-Yen is always in Hyper Mode, but its armor is not weakened and its attacks are more powerful than the regular Fei-Yen.
- Waku Waku 7 and Galaxy Fight, the two fighting games made by Sunsoft for the Neo Geo, shared a common bonus boss named "Bonus-Kun", a punching bag (from "the Punching Bag Planet") with a limited moveset who parodies Ryu. In Galaxy Fight, after you defeat Felden, you get to fight a final Bonus Boss in the form of Rouwe, an old man dressed in a karate gi.
First-Person Shooter
- Mega Man 8-Bit Deathmatch: In v5, if you defeat Bass in the Mega Man 7 chapter without using the Super Adaptor, you'll be able to fight the Wily Capsule, the original chapter 7 boss that Bass replaced.
Hack and Slash
- Diablo II has some in its later updates. Versions 1.00-1.09 had the Cow King as a sort of optional boss, though he was substantially weaker than the actual final bosses.
MMORPGs
- World of Warcraft:
- Wrath of the Lich King introduced optional bosses in some of the regular dungeons that are only accessible on Heroic difficulty. However, the WotLK optional bosses tend to be much easier than the Final Boss of their respective dungeons.
- The Bug trio, Viscidus, and Ouro were all optional bosses in Temple of Ahn'Qiraj. Most, if not all guilds, did the Bug trio because the fight wasn't very difficult and it rewarded good loot. Viscidus is a fight that many guilds skipped because, even at level 80, it's still a pain in the ass. To defeat Viscidus, he must be frozen; naturally, he can only be frozen by Frost-based attacks, such as Mages' Frostbolt or Shamans' Frost Shock. Once Viscidus is frozen, then everyone in the raid must melee him (yes, even the healers need to). If melee'd enough times, he will shatter. All while attempting to freeze and shatter Viscidus, the raid must survive near-constant AoE Poison damage. Ouro is a fight that most Alliance guilds would skip in favor of C'Thun because A) he offered better loot and B) killing C'Thun at 60 was a significant achievement for raiding guilds. (Horde guilds would run him over due to Poison Cleansing Totem.)
- Wynncraft has several Boss Altars located around the world, which let you fight special bosses that aren't tied into any quests, but drop items unique to them. These are accessed by feeding the altars a certain amount of a specific item, which are usually dropped by mobs in the area where the altar is located. These bosses can only be fought once every time the altar is activated, so players should have multiple of the required items if they intend to make repeat attempts at the bosses.
Platform Games
- Mega Man Zero 3: If the player enters the Cyberspace in Sub Arcadia, he'll have a secret fight with Phantom. Defeating him at a high rank will grant Zero a very useful EX Skill.
- Sonic the Hedgehog 2, in later releases of the game such as the smartphone and Sonic Origins version, adds a secret level, the Hidden Palace Zone, which has its own boss fight against Eggman. If this route is taken, the usual boss of Mystic Cave Zone will be skipped.
- Super Mario Bros.:
- New Super Mario Bros..: World 4 and 7 are entirely skippable if you want to complete the game without using the Mini-Mushroom, making their respective bosses (World 4's Mega Goomba, World 7's Lakithunder) fit the trope.
- New Super Mario Bros. 2: The non-numbered worlds (World Mushroom, World Flower, World Star) are entirely optional, making their respective bosses (Mushroom's Larry Koopa, Flower's Lemmy Koopa, Star's Dry Bowser) this. As a matter of fact, World Star can only be revealed after you defeat Bowser in World 6.
- New Super Mario Bros. U: Depending on which path you choose after defeating Morton Koopa Jr. in Layer-Cake Desert, you can complete the main game without either taking on Larry Koopa in Sparkling Waters or Wendy O. Koopa in Frosted Glacier, as both victories result in Soda Jungle being unlocked, starting with the game's first airship level and boss fight with Bowser Jr.
- Wario Land: Super Mario Land 3: Hinyari is located in Sherbet Land. Amusingly, you can just walk right out of the battlefield through a conveniently placed door.
Puzzle Games
- Dr. Mario 64 has two optional bosses with similar conditions; if you get through Story Mode on Normal difficulty or higher without losing or restarting a match, then upon defeating Rudy, whichever character you're not playing as will challenge you one last time for the rights to the Megavitamin bottle. If you're playing as Mario, then Wario will power up into Vampire Wario; conversely, Wario will have to contend with Metal Mario. Defeating them first try will unlock them in Versus Mode, where they're not only playable but also have the hardest AI.
- Collecting all 24 tickets in Pony Island changes the ending to Hopeless Soul telling you that he now understands that you want a satisfying reward for getting full completion and fighting you in a three-stage boss battle using different gameplay segments to supply that reward.
- Puyo Puyo: Carbuncle has played the role of optional boss twice in the series. To wit:
- In Puyo Puyo Sun, he can be fought in Schezo's story without using a continue.
- In the first Puyo Pop Fever, he can be fought either by reaching Accord on the Hara Hara route without continuing (while ensuring that Fever mode is used either less than four times or more than twelve) and defeating her or by continuing with a multiple of 7 when defeating her.
- Puzzle Quest 2 has five optional bosses: Kurak the polar bear, the Yeti, the Cave Ogre, the Arch Lich, and the Green Dragon. They're unlocked automatically as you level up, so you can tackle them at your leisure or not at all. Since the rewards they yield aren't any better than most high-end enemies in the game, they aren't worth the effort to beat, unless you're a completionist, an achievement hunter (which you don't even get, depending on the platform) or for the bragging rights.
- Sutte Hakkun has the Purple Makkun, an odd-colored Makkun that hides within specific crevices in certain stages in every world, serving as the replacement for the Bonus Stages of the Satellaview versions. He's the only character in the entire game that attacks you in any form: upon finding him, he'll scoop you up and challege you to a race in one of his ten Battle stages (which have the same level of difficulty as the regular stages). Beat him, and you'll get a segment of the Solution code to write down.
Real-Time Strategy
Rhythm Games
- Everhood has the Spirit of Light, who, when beaten, gives you one of the three gems needed for one of the Multiple Endings.
- Frederic: Resurrection of Music has three optional songs/opponents that can be fought in Arena Mode. You need to beat the game three times (once for each difficulty except Too Easy) to unlock them all.
Roguelikes
- Absented Age Duology: All Core dungeons have an Arc Monster near the end of the stage. These bosses are optional, but are also powerful enough to rival the actual Gänger boss of the dungeon. They are also the only enemies with 100% gem drop rates.
- In Hades, the player can choose to steal money from the boatman Charon to start a fight with him.
- In Spelunky 2, a boss called Vlad can be encountered by doing a small secret side quest to activate a drill that digs down into the volcano level. This has no bearing on the story or the run, but rewards players with an unique item. Also doubles as a Route Boss.
Role-Playing Games
- Abomi Nation: After collecting 5 of the 6 artifacts, you can fight an optional boss Abomi who gains stat boosts at the start of the fight and is scaled to always be above your level. You are rewarded with Macrogame currency if you win.
- In Alpha Protocol, the Blood Knight Action Girl SIE will offer to team up with you during the mission where you first encounter her. You can agree to the alliance, or you can attack her (or you can agree, complete the mission, then attack her when you encounter her again at the end of the mission). Not only will she not die when you win, but your rep with her will increase.
- Axial Series:
- Axial Disc 1:
- Relggiw is a powerful boss that's a negative-colored Wiggler, which can be encounter in a small pool of water in the Mirror Caves.
- Raye is an optional boss in Bluewood Forest, who tries to throw the player off their game with her multiple forms, which are based on the Sky Striker archetype of Yu-Gi-Oh!.
- The first Axial, Lion, is an optional boss in Stardust City's sewers and will likely be the player's first taste of what an Axial other than Amara is capable of.
- The newest Axial, Axis, can be fought in Astral Point, and his stats are only second to Tefka's. Beating him is necessary to show the full ending of the game.
- Axial Disc 2: The game has several bosses that are balanced to be fought before the final dungeon, but they aren't mandatory.
- Doppelganger 064 tasks the party with defeating their Doppelganger counterparts, all of which have gimmicks that the player needs to think around. Beating them is necessary to unlock the postgame Doppelganger fights.
- The Bookwyrm is the only mandatory Axis memory boss. The other memory bosses are the Braineater and Brawneater duo, Scrappeater, Nesseater, Puncheater, Thirsteater, Defeatricity, Diggeater, and Necromeater. The player only needs to defeat four of the remaining memories in order to enter the final dungeon, but beating all of them is necessary for the True Ending.
- Jean is a Duel Boss for Chip in Markton, and beating him earns the party Jean's summon accessory.
- Axial Disc 1:
- The Baldur's Gate series:
- Most of the dragons in the game are also optional fights, though they give some good rewards after being slain.
- There's also an optional (and completely story-irrelevant) fight against a demon knight at the bottom of Durlag's Tower.
- The Twisted Rune is an order of evil spellcasters who, when you enter their lair, assume that you've come to foil their plans and attack you. They're sensibly skeptical if you claim to have found them by accident, because the only way that would happen is if you were wandering around a bad part of town while carrying an incredibly rare and valuable type of gemstone and opening doors at random. (This is in likely exactly what happened, unless you looked at a guide. The clues that would lead you to them were never put into the game.)
- Kangaxx the demilich is a hidden quest that you can undergo as early as in chapter 2, but for most players it would be much wiser to postpone the deadly skull.
- The Watcher's Keep is an extra content with a series of dungeons ending in the possible confrontation with Demogorgon. Since you can seal the demon forever rather than undergo a very difficult battle, this is a trope within a trope, in that it is a skippable optional boss.
- Baldur's Gate III: Most of the boss fights in this game are actually skippable through dialgue choices or by simply avoiding them. In fact, this game actually has only three required boss fights players will have to face at some point, namely Balthasar, Ketheric Thorm and Orin. However, skipping the other bosses is not recommended, as this will lock you out of some much needed experience points. Some notable examples optional bosses are:
- The Three Goblin Leaders in act 1. These can be tough fights if you come unprepared and underleveled. However, there is nothing stopping you from allying with them or simply walking away from their conflict with the local druids.
- A fight with Lord Gortash can be avoided by allying with him.
- The final bossfight can be avoided if Gale is present in the party and convinced to blow himself up with his magical orb..
- Barkley, Shut Up and Jam: Gaiden:
- The spirit of Dikembe Mutombo is the boss of a bonus dungeon and gives Barkley the Holy Dunk attack.
- A duergar (actually Balthios, who is a Wereduergar) can be fought if you take the ferry to Liberty Island instead of the Underground Railroad.
- The Ghastly Darklord is encountered by checking a seemingly empty corner in Proto Neo New York.
- Kevin Garnett is the final opponent in the Arena in the optional B-Ball Dimension.
- Baten Kaitos Origins: Nasca, Valara, Heughes, and Wiseman are optional bosses fought to tie up loose ends; one of them allows access to the game's True Final Boss. There's also Arma Prototype M, a.k.a. The Wicked Gawd, who is the final boss of the Coliseum and is absurdly hard.
- The Xbox 360 game Blue Dragon has several Dragons that don't need to be beaten, but give the player a useful accessory if they are.
- Corruption of Laetitia: When fighting the Predatory Birds in the map north of Gruhnwald, there's a chance that Hawkzombie will show up in the second turn to fight the party.
- Bloodborne: Rougly half the bosses in the game aren't strictly necessary to reach the end of the game. However, several of them are necessary to unlock certain features of the game or even entire optional levels, and most of them provide important background lore to get a fuller picture of what's going on in Yharnam. Of course, if you've never played the game before, you don't know which bosses are necessary and which ones aren't.
- The first boss most players will encounter, the Cleric Beast, is not actually blocking progress to anything. However, killing it will get you the Sword Hunter Badge, which unlocks several useful items from the Messengers, including a key item that turns the Blood-Starved Beast into a Skippable Boss.
- Henryk the Old Hunter can only be encountered if the player decides to progress Eileen the Crow's quest line, as he will never appear otherwise.
- The Afflicted Beggar Mini-Boss can be encountered at either the Forbidden Woods or the Cathedral Ward, but does not actually have to be fought in order to progress. Beating him does net the player a powerful Beast Rune, however.
- The Witches of Hemwick do not need to be fought in order to progress the story, though beating them does grant the player access to Caryll Runes.
- Martyr Logarius is found in a very secluded area in the Forsaken Cainhurst Castle, which in of itself is an optional area that requires a special item to access.
- The Celestial Emissary is an optional encounter that only needs to be beaten to encounter Ebrietas, who herself is also optional.
- Ebrietas, Daughter of the Cosmos doesn't need to be fought to progress the story, only being required to unlock more Chalice Dungeons.
- Darkbeast Paarl is a boss encountered in Yahar'gul at any point after reaching the area, but does not actually need to fought to progress.
- Amygdala does not need to be fought to progress the story, and the only reason the player would ever need to fight them is to unlock the Ailing Loran Chalice Dungeon.
- Yharnam, Pthumerian Queen is only encountered within the deepest of the game's optional Pthumerian Chalice Dungeons.
- Bug Fables: There are multiple criminals and hostile bugs fought as mini-bosses in sidequests or by exploring, the Mother Chomper, encountered in an optional dungeon, the Broodmother in the power plant sidequest, and the five Bounty Bosses you can take from Underground Tavern's side quests that are a major step up in difficulty compared to the storyline bosses.
- Clair Obscur: Expedition 33:
- Chromatic Nevrons can be found throughout areas, acting as King Mook versions of existing foes and usually having harder versions of their movesets along with added extra moves and even special passive abilities. They don't have impact on the plot and are usually well-hidden, with Gestrals advising you to seek them if you're looking for extra challenge.
- Mimes are a Boss in Mook Clothing variety, not having a boss healthbar but otherwise being quite powerful. Defeating them grants cosmetics they are wearing and some items.
- Even outside aforementioned two groups, some unique opponents can be found in optional areas the Expedition can visit.
- Dark Souls:
- Dark Souls I:
- The Stray Demon can only be encountered by returning to the Undead Asylum, and going back there is not only a completely optional challenge, but even finding out how to get back there is not an easy thing to do. Fighting it is worthwhile, however, as it is the only enemy guaranteed to drop a rare Titanite Slab, an item needed to reach the final upgrade of any standard or lightning weapon.
- Both Hydra Mini-Bosses are this. The one encountered in Darkroot Basin can be easily ignored, especially given how much of pain it can be to fight if the player doesn't have the Rusted Iron Ring, and the only reason the player would ever need to confront it is that killing it grants access to the Artorias of the Abyss DLC, which is also optional. The one encountered in Ash Lake is also this by virtue of the fact that Ash Lake itself is a completely optional area.
- The Moonlight Butterfly is found in an area of the Darkroot Garden that's very out of the way in terms of exploration. Beating it earns the player the Divine Ember, which is needed to create divine weapons, and the Watchtower Basement Key, though this item is rendered moot if the player has the Master Key.
- The Great Felines Mini-Boss can be found on one of the paths to the Darkroot Garden, but because players are more likely to enter the forest through the seal gate, and there's a much faster path than either one of these anyway, it's entirely possible to never encounter them. The fact that they don't drop nor guard any loot also discourages the idea of fighting them.
- Dark Sun Gwyndolin is an entirely skippable encounter that many players can easily miss, due to him hiding behind an illusionary wall that can only be passed by either wearing the Darkmoon Seance Ring or by killing the illusionary Gwynevere.
- Crossbreed Priscilla can only be found in the optional Painted World of Ariamis, and even then does not need to be fought in order to complete the level due to only turning hostile if the player attacks her first.
- Because the Artorias of the Abyss DLC does not need to be completed to finish the game, all 4 of the boss fights found in it are completely optional. Among them, however, Black Dragon Kalameet is this even in the context of the DLC. He's the only boss the player doesn't have to fight in order to complete the DLC's main story, encountering him requires the player go out of their way to do so, and it's impossible to properly fight him until the player talks to Gough, who himself can be hard to reach.
- Dark Souls II:
- The Belfry Gargoyles don't need to be fought, appearing in the optional Belfry Luna area. However, beating them does make the fight against the Lost Sinner easier, as beating them earns the player the key needed to unlock a room with a torch that can be used to light up the Lost Sinner's boss room.
- While Vendrick must be encountered in order to progress the game's story, actually fighting him is completely optional. Not helping matters is that it's next to impossible to damage him without first gathering the Souls of a Giant, which are scattered around the world, with one of them being guarded by another optional boss.
- The Ancient Dragon does not need to be fought to progress the game, and it will only attack if the player provokes it anyway. Beating it nets the player a Soul of a Giant, which does make the fight against Vendrick easier, though that fight is optional as well anyway.
- The Darklurker is one of the most easily missed bosses in the series. Not only is fighting it not required to beat the game, but actually getting to it is a challenge, as it can only be found in an area that can only be accessed by joining the obscure Pilgrims of Dark covenant. Beating it will complete the player's progression in said covenant.
- Because The Lost Crowns DLC trilogy does not need to be completed to finish the game, all 9 of the boss fights found in them are completely optional. Among them, Crown of the Sunken King's Afflicted Graverobber, Ancient Soldier Varg, and Cerah the Old Explorer, Crown of the Old Iron King's Sir Alonne and the DLC's version of the Smelter Demon, and Crown of the Burnt Ivory King's Lud and Zallen, the King's Pets are this even in the context of their respective DLCs. All of them are encountered in secret areas of their respective DLCs, and none of them need to be beaten to complete the DLCs' stories.
- Dark Souls III:
- The Curse-rotted Greatwood does not need to be beaten to travel to the next area, and the Giant Archer's greatarrows can end up discouraging the player from trying to reach the Curse-rotted Greatwood anyway. However, beating it earns the player the Transposing Kiln, which is needed to turn boss souls into weapons, equipment, and spells.
- The Stray Demon Mini-Boss does not need to be fought to progress through Faron Keep, as it is only found in a very out of the way location in the area.
- The Old Demon King is very easy to miss, as reaching the area he's found in requires cutting down the bridge in the Catacombs of Carthus. And since the game encourages the player to steer clear of the bridge and find another route, it's entirely possible to go through the game without even knowing of the area's existence.
- Oceiros, the Consumed King can only be encountered by taking a detour before reaching Lothric Castle, and killing him is not required to progress the main plot. However, beating him does grant the player access to Archdragon Peak and the Untended Graves.
- Champion Gundyr is found in the optional Untended Graves area, which itself can only be accessed by beating the optional boss fight against Oceiros. However, beating him is necessary to getting the "End of Fire" ending, as an item needed to achieve that ending, the Fire Keeper's Eyes, can only be found in an area blocked off by him.
- Because the game's DLCs do not need to be completed to finish the game, all 6 of the boss fights found in them are completely optional. Among them, Ashes of Ariandel's Champion's Gravetender and Gravetender Greatwolf and The Ringed City's Darkeater Midir are this even in the context of their respective DLCs. The Champion's Gravetender and Gravetender Greatwolf can only be encountered if the player cuts down the bridge to Ariandel Chapel, and the two don't have any relevance to the DLC's main plot, only existing as a wall between the player and the Arena added in the DLC. Darkeater Midir, meanwhile, can only be reached by the player going far out of the way of the main areas, and even then, fighting him requires they first beat him when he attacks them in the path to Filianore's Church.
- Dark Souls I:
- Deltarune:
- In Chapter 1, you get to find and ultimately fight the locked-away Jevil, whose fight makes the Final Boss look tame through sheer Bullet Hell, with his attacks being fast-paced and leaving little wiggle room to avoid. Depending on how you defeat him, you'll either end up with the best armor in the chapter or one of Susie's best weapons.
- Chapter 2 features another, similarly out-of-the-way secret boss: Spamton NEO, an upgraded form of a boss fought earlier in the chapter. The spoils for beating him are determined the same as with Chapter 1's Super Boss: a piece of equipment for sparing him, or a weapon for Ralsei for defeating him. If you undertake the Weird Route, however, it's subverted as Spamton NEO ends up becoming the Final Boss of the chapter as Queen doesn’t bother trying to fight the heroes, and ambushes Kris alone at the Dark Fountain.
- Beating Tenna's boards in Chapter 3 with an S-Rank will unlock access to the original game the boards were based on, and accessing it all three times you can will lead you to something/someone from within the game in possession of the Shadow Mantle attacking you, with the damage it deals to the in-game character being translated to Kris. Victory results in you obtaining the Shadow Mantle, and while technically you don't need it, if you want a better chance of getting the Chapter's Shadow Crystal from The Roaring Knight it's ideal to get the Mantle.
- Chapter 4 has another Superboss in the vein of Chapter 1/2 with the Old Man/Gerson Boom, but also possesses a more traditional Optional Boss in Mike, Tenna's Number Two, or rather the three impersonators since Mike may or may not exist to begin with. While you're only given the code to access them by reloading your Chapter 4 save, you can access them the first time you go to Castle Town if you know it already. Said boss uses a vastly different control scheme, using both your microphone and the mouse/right trigger and right stick to dodge and interact with attacks, or use both Joycons in mouse mode on the Switch 2. Beating them doesn't really get you anything aside from access to some minigames using their control scheme, Pluey, Battat and Jongler.
- Demon's Souls has Old King Doran, who the player can be easily go without seeing and still complete the game. However, fighting him to the point of impressing him will earn the player the Demonbrandt, and killing him outright will get them his armor and the very useful Eternal Warrior's Ring.
- The Denpa Men:
- The first game has two optional bosses. One mid-game dungeon appears to have two bosses—a Water-type Golem and an Ice-type Golem. The Ice-type Golem is more difficult to get to, and is the true boss of the dungeon. The Water-type Golem, however, gives you a few extra goodies if you beat it. At the very end of the game, you can also choose to fight The True King, the final form of the King of Evil. He has his own Rare Random Drop, and each time you defeat him, he drops an emblem that can be sold for a tidy sum of money.
- The sequel has even more optional bosses than the first, most of whom are based around chess pieces. Each of the four Caves of Darkness contains a different variation on the Knight, and each one is progressively more difficult—especially because the Caves are timed, and even though you can keep battling if you run out of time, if you do, you'll be kicked out of the dungeon before you can collect your rewards for completing it. There's also a Pawn who you have one required fight against early on—but he keeps getting stronger and stronger throughout the game, and you can return to challenge him after different story events. The last two sets are linked—the "big" Bonus Dungeon ends with a fight against the Demon Queen, who serves as a combination of this and a True Final Boss. This unlocks the Bishop, King, and Queen, who fight you back to back in a Call-Back to the original game's final boss.
- Digimon Story: Time Stranger has a ChaosDramon wandering around the prologue stage. It is meant to teach players how to be stealthy, being a Level 65 Mega-Generation Digimon when you only have Rookies at best.
- Elden Ring: Most bosses are actually optional, for whatever reason.
- The Shardbearers are the main storyline bosses, but there are six of them and you only need two of the Great Runes they hold. So if you want a quick game, you could just fight Godrick the Grafted and Renalla before heading off to Leyendell, but it's totally possible to go for Mohg instead if you're feeling masochistic.
- In fact, out of all the Elden Ring bosses, the only absolutely necessary ones are whichever Shardbearers you choose, Godfrey's golden shade, Morgott, the Fire Giant, the Godskin Duo, Maliketh, Godfrey (the real one this time), and then the final boss. All others can be skipped, though their rewards are generally useful.
- All field bosses can be avoided simply by never entering their aggro range. Some also won't spawn outside of certain conditions (the Bell-Bearing Hunter only spawns at night, for example).
- Any enemy past a fog gate, aside from the mandatory ones mentioned above, can be skipped if the player doesn't want to enter their arena.
- All Evergaol enemies are locked away in extradimensional prisons and can't do anything to you unless you seek them out.
- All of the dragon bosses are avoidable simply by avoiding their territories. Dragonlord Placidusax won't even attack you in his boss arena until you get too close, and Fortissax is a Route Boss for Fia's sidequest.
- Both the Ancestor Spirits are bosses of optional areas.
- The Astel fights won't even appear unless you defeat Radahn, who can also be skipped.
- The EarthBound ROM Hack EquestriaBound has a few optional bosses, who always drop the parties Infinity Plus One Swords. According to the hack creator, this was to prevent Sword of Kings situations.
- Final Fantasy:
- Final Fantasy IV: There are four optional bosses that become Eidolons once you beat them: Asura, Leviathan, Odin, and Bahamut. Only one of these was particularly difficult. The others required very specific strategies rather than a high-leveled party to defeat, making them closer to Puzzle Bosses than anything else. This was fitting, as the battles were intended to be tests of your skill.
- Final Fantasy VIII: The Brothers are optional bosses, as are the Jumbo Cactaur, Odin, Tonberry King and Bahamut.
- Final Fantasy X-2:
- The Experiment, a Machina the Machine Faction in Djose Temple are working on throughout the game, which can be upgraded with parts the player obtains from digging in the Bikanel Desert. It is completely optional, and you only have to fight it for two points in the 100% Completion: the Djose Temple Episode Complete, and the Annihilator Blue Bullet.
- Angra Mainyu, a gigantic snake-like Fiend slumbering in the Bikanel Desert. It can be encountered as early as Chapter 1 during digging sessions if the player is unlucky, but to actually fight it in a proper battle, the player must complete a long sidequest first, one that begins in Chapter 3 and can only be concluded in Chapter 5.
- Final Fantasy XII has lots of these, as part of an assortment of sidequests which many argue form 75% of the game's content. For instance, there are thirteen Espers, but only five are necessary to proceed with the story, which means you have to seek the other eight on your own volition. Non-Esper optional bosses include Earth Tyrant, King Bomb, Gilgamesh, Phoenix, Shadowseer, Hell Wyrm, Yiazmat, and Omega Mark XII. While you face Ba'Gamnan early in the story, he can be fought again much later in a sidequest, where he is much stronger.
- Fossil Fighters: There is a huge slew of optional bosses bosses, one of which opens up before the final boss, and the rest of which appear afterwards, in the Playable Epilogue.
- The Legend of Dragoon: In the dungeon before the Point of No Return, you are given the opportunity to fight the spirits of the three dragons you defeated. They drop some useful attack items, and they're also guarding chests containing powerful equipment.
- The Legend of Heroes - Trails:
- The Legend of Heroes: Trails in the Sky: The four bosses encountered in The Abyss; getting the fourth to appear is a bit of a Guide Dang It! Each one yields a piece of Zemurian Ore, and beating all four nets a chance to gain a new weapon.
- The Legend of Heroes: Trails of Cold Steel: Aurier, the Optional Boss of Vantage Masters (who can only be challenged if you have all 22 cards), has an exclusive Master to be earned once beaten; the Paladin.
- The Legend of Heroes: Trails into Reverie: The 10 Trial Door challenges, optional battles involving select party members having to fight against certain boss characters. If the player wins, each character used will get one updated Craft (some of which are S-Crafts).
- The Legend of Heroes: Trails through Daybreak: If you've maxed out any of the three alignments, the final dungeon will feature a corresponding hidden boss, which can be defeated in exchange for material to make the party's ultimate weapons. As such, having five points in all alignments will allow the player to give three characters their best weapons.
- Liar Jeannie In Crucifix Kingdom has the two elite Pleiades Knights, Celaeno and Alcyone, as optional bosses who guard the exit of the kingdom and must be defeated to get the secret ending.
- Look Outside: Technically, you don't need to fight any boss enemies to reach the end of the game. However, you can only reach the No Going Back and Failed Ritual endings by doing this; getting any of the other endings requires fighting at least some bosses. However, several bosses are still totally optional in every possible route.
- Lost Odyssey has seven optional bosses: Persona, King Kelolon, the Cave Worm, the Blue Dragon, the Holy Beast, Legendary Spirit Sorcerer Fu, and The Immortal One in the Backyard. Players with access to XBox Live can get a new downloadable dungeon with an extra boss Professor K, aka The Killalon.
- Luminous Plume: Returning to older areas like the Mystic Forest, Arctic Lake, Tempest's Heart, and Mt. Arzen allows Raven to fight optional berserker bosses.
- Lunarosse has two post-game bosses. One is implied to be a Greater-Scope Villain for the creator's future projects and the other tied into the Sequel Hook.
- Marvel: Avengers Alliance has the Epic Bosses in certain missions, which only show up if you fight every battle and complete every deploy (which often require spending rare Command Points to recruit specific heroes) in that mission. The bosses offer stronger weapons and gadgets and higher chances of winning more Command Points as prizes for defeating them, compared to normal bosses.
- In the first Megaman Star Force, three of the FM-ians are only there to provide optional Boss Battles, namely Cancer Bubble, Wolf Woods, and Crown Thunder (post-game).
- Mega Man X: Command Mission has two Bonus Bosses plus another set of nine. Rafflesian and Duckbill Mole gave X, Zero, and Axl new abilities that were useful in what remained of the game by that point. Ninetails and the preceding eight Tails Clan members could only be fought after beating the final boss, making the rewards for beating them worthless.
- Mother 3 has the Ghost Knight (encountered in Osohe Castle) and Li'l Miss Marshmallow (encountered at the top of Thunder Tower), both of whom will ignore you if you choose not to engage them; Li'l Miss Marshmallow, in particular, will only attack you if you try to examine the yo-yo in the playroom at the top of Thunder Tower (you get to keep the yo-yo and use it as a weapon if you defeat her). The Ghost Knight is an animated suit of armor with a sword and a shield, and Li'l Miss Marshmallow is Porky Minch's robot maid.
- The Gundam RPG MS Saga: A New Dawn has Ultima Gundam and Omega Gundam, made from a mix of parts from Mobile Fighter G Gundam and Mobile Suit Gundam Wing mecha respectively. Their names are obvious homages to Final Fantasy's perennial Bonus Boss pair, Ultima Weapon and Omega Weapon.
- Parasite Eve (1998) had a few optional bosses in the Chrysler Building. While most of the bosses are color swaps of the storyline bosses, the giant cockroach and giant bee were exclusive to the building. The original Eve is at the very top of the building, and defeating her gets you a different ending.
- Pillars of Dust: In the final chapter, the party can find a key that unlocks a secret room underneath a tomb. This contains a portal to the world in Shadows of Adam, resulting in a fight against Kellan, Asrael, Curtis, and Talon.
- Resonance of Fate pits you up against Sullivan and Rebecca at the end of Neverland. They are generally pushovers, especially compared to what you fought to get to them.
- Robopon: In the original, you can rematch the first six Legends in Zero Tower post-credits. The second game has several, including Rena's restored-to-youth mother, the younger version of Nick D., the Robopon in Delica Castle's basement, and the W-King.
- In the SaGa series, most of the game is optional, including many of the bosses.
- Sailor Moon: Another Story has Esmeraude as an optional boss in the fourth chapter. Beating said boss gets you a second Red Pupil.
- Soma Union: The game lets the player save after they beat the game once, allowing them to fight the Sunset Squad, the Cooler Crusader, and the library's copy machine.
- The Spirit Engine 2 has a variant: the bonus boss, Urtat Underval, is fought roughly halfway through the game rather than at the end. Another variant is that you fight him twice; once as a human, and once as a hulking zombie.
- In Act IV of Super Lesbian Animal RPG, the four sons of Javis each set up lairs in different parts of the world. Their fights each have a different, unique challenge to them, and defeating them will grant the party powerful equipment.
- The Super Mario Bros. RPG games:
- Super Mario RPG has three:
- Tiny martial arts master Jinx, who you can fight three times after defeating his apprentice, Jagger, each fight harder than the last. The boss lives in Monstro Town.
- Mokura, a green cloud miniboss that may appear in Land's End or Belome's Temple, dodges the player unless they track the boss down, and has two forms.
- The game's Superboss: the Final Fantasy Shout-Out Culex, a powerful magic-using entity from another dimension who attacks using four elemental crystals and is harder than the game's Final Boss. It too lives in Monstro Town.
- The 2023 Nintendo Switch remake adds rematches with Belome, Punchinello, Booster, Torte, Bundt and Raspberry, Jinx, and Johnny in the postgame, all of which can wipe you out if you're not careful, as well as Culex 3D, who as his name implies he's now in 3D and much more powerful.
- Paper Mario 64:
- The Anti Guys, of which there are four. The first one is guarding a treasure chest in Shy Guy's Toy Box and can be easily bribed via Lemon Candy to step aside. The other three are fought if you fail the second Bowser door's quiz.
- Kent C. Koopa starts blocking the path to Koopa Village halfway through the game. Though he brags he's really tough if you choose to fight him (and to be fair, he is if you fight him normally), he's really vulnerable to sleep inducing attacks. You can also just use the Warp Pipes in Toad Town Tunnels to skip him, which he's apparently too dumb to realize.
- Paper Mario: The Thousand-Year Door:
- Atomic Boo, fought in Creepy Steeple if you enter the main hall and take the Spin Hammer attack to the swarms of Boos enough times. He isn't particularly hard, but knowing he even exists is a bit of a Guide Dang It!.
- Bonetail, the oldest and strongest of the Shadow Queen's three dragons, is the {{superboss]] of the optional Pit of 100 Trials.
- The Nintendo Switch remake adds Prince Mush, the original champion of the Glitz Pit who was revived at the end of the chapter but was The Unfought in the original game, and you get the opportunity to fight him in an exhibition match after completing the Glitz Pit a second time, and as a new superboss he easily gives Bonetail a run for her money in terms of difficulty
- Also in the remake there is Whacka, a superboss fittingly found at the bottom of the Pit of 100 Trials after you've already beaten Bonetail.
- Super Paper Mario:
- You can rematch Francis, Chapter 3's boss, in the final chapter's second episode if you tell Mimi (disguised as Merlee) that you fear him most.
- Both Flipside and Flopside Pit of 100 Trails are optional dungeons just like its predecessor, so you can expect their respective bosses, Wracktail (a stronger version of Fracktail) and Shadoo (taking on darker forms of the heroes: Luigi, Bowser, Peach, and Mario respectively), to be optional bosses as well. Shadoo takes it up a notch where you have to do the entire dungeon again to fight it.
- After you beat the game, Sammer's Kingdom is restored, which means you get to finally have a chance to do the entire Duel of 100 — culminating in End Boss as the last Sammer Guy you get to defeat to win the ultimate prize.
- Mario & Luigi: Bowser's Inside Story: Returning to Bowser's castle as Mario and Luigi and solving the cold-storage vault puzzle using hints scattered along the path to said vault let's the bros fight three Shroobs. They do a lot of damage but have relatively small health and simple attack patterns. Defeating them rewards the bros with the powerful Magic Window attack. There's also the Challenge Node which has X versions of some bosses, including Bowser X at the end of the Gauntlet.
- Mario & Luigi: Dream Team has an analogue of the above in the Battle Ring, which contains X versions of some bosses, inclusing all the Giant bosses, and Bowser Jr. takes place of Bowser X at the end of the Battle Medley. Out of these, only the battle with Grobot X is required to progress the story in order to obtain one of the materials for the Ultibed.
- Likewise, Mario & Luigi: Paper Jam has the Battle Ring, except that the bosses are not X versions, just have higher stats, and Bowser X and Bowser Jr. are suceeded by Dry Bowser at the end of the Battle Medley.
- Mario & Luigi: Brothership has stronger Glohmed versions of the bosses of each of the first three Great Lighthouses, boasting much higher stats and the ability to inflict a status ailment that prevents the brothers from cooperating with each other. They become available one-by-one at a set distance in the main story after beating their first fights.
- Super Mario RPG has three:
- Uncommon Time has an optional boss at the end of each Bonus Dungeon: Altair at the end of Aubrey's Uncommon Time, and Arietta at the end of Arietta's.
- Ragu o Ragula is an optional boss in all of the Wild ARMs games for PlayStation, PS2, and PSP. Angolmois also appears in some of them. In fact, the Wild ARMs games have many bonus bosses, often found sealed in crystals found throughout the game. Ragu o Ragula is neatly incorporated into all of these titles as the sleeping demon who is fated to destroy Filgaia, centuries after the conflict-of-the-day is finished off. Big extra credit for overachieving heroes. The other bonus bosses can range from Call-Back characters, characters who are no longer a part of the main plot and have been more-or-less forgotten by the main cast, and nudie mags
- A Witch's Tale has a bonus fight with friendly vampire Loue, who suddenly turns not-so-friendly for the fight. If you win, you get a game-breaking doll.
- The World Is Your Weapon: Defeating the Demon Lord is not necessary to get the first ending, but beating him is necessary for the third and fourth endings. He and the Final Boss can also be fought in rematches so that the player can capture them. In version 2.40+, Weaco will have to fight a third version of the Demon Lord to get the secret ending.
- Xenosaga:
- Episode 1 has four: two mechas, Din Gareth and Jin Gareth, the sharpshooter Great Joe, and Mintia, an evil version of MOMO.
- Episode 2 has a metric-buttload of optional bosses encountered in the game's many sidequests.
- Episode 3 has two mechas: Omega Universitas AKA Id Weltall and Erde Kaiser Sigma. The latter is the only mecha in the game who's fought without the use of E.S.s.
- Xenoblade Chronicles:
- Xenoblade Chronicles 1: One long sidequest chain with its own story that covers almost half of the game leads to a bonus boss. Though this one is not overleved, it stands out because the quests that lead to it can be lost forever, the battle is under a tune only reserved for a few select Hopeless Boss Fights, and the boss is one of the NPCs involved in the sidequest chain: Bana, the Nopon Kingpin.
- Xenoblade Chronicles X: Neilnail Albus and Neilnail Furvus, a pair of Skells fought in the 'Twin Dolls of Mystery' Time Attack mission, were originally supposed to be a story boss, but that plot thread was scrapped. They're still present in the game to be fought optionally, because defeating them yields unique items necessary to craft Level 60 Skells, among them the powerful Ares 90.
- Xenoblade Chronicles 3: Consul X only appears in one cutscene of the main story, however, she can only be fought if the player goes through Eunie's Ascension Quest, where she is fought together with another boss. If this question was not completed, then the segment where the party finds and kills her in The Very Definitely Final Dungeon gets replaced by a minor fight with generic grunts.
- The Yo-kai Watch series has these kind of bosses almost religiously in both the main and spin-off games, and a few of these bosses are noticeably harder than even the Big Bads of said games.
- The first game features the Infinite Inferno, which contains Palette Swaps of several main story bosses, including McKraken's second form — but oddly, excluding Tarantutor — which were imprisoned there for various reasons. The main attraction, however, is Wobblewok, which causes a lot of Yo-kai energy to leak to the human world due to the seal containing him being set loose. Also, Chirpster and Duwheel are this for examples outside of the Inferno.
- Yo-kai Watch 2 brings back the Infinite Inferno with the same bosses, but also adds the Divine Paradise, which has palette swaps of several bosses of the main story of said game — excluding Gutsy Bones and Eyeclone, whose recolors appear elsewhere, and Meganyan, with no recolors at all — and has Kat Kraydel as an unique boss, who is the cause the summer is seemingly extending infinitely -as Hovernyan states at the beginning of the post-game.- The second bonus dungeon is the Mystery Way, which features palette swaps of Gutsy Bones, Eyeclone, and Hans Full, though the three versions of the game must be connected in order to fight all four of them. In addition to bringing back Chirpster and Duwheel as well, the aforementioned Hans Full, Retinado (another palette swap as part of the Gates of Whimsy sidequest) and Mallice (at the end of the Infinite Tunnel) appear as additional bosses. The 2.0 update and the third version add Rubeus J, Hardy Hound and Hinozall in the Psychic Blasters mode, and Bronzlow, Teastroyer, Infinipea, Headsteam, and Kabuking in additional sidequests and locations.
- Yo-kai Watch 3 drops both the Infinite Inferno and the Divine Paradise as well as the Mystery Way, but adds the Tower of Zenlightenment, where the bosses, which are fought in the four penultimate floors are Daruma-themed palette swaps of Orcanos, Chipster, Duwheel and Slakerjack, and in the last floor, The Zenlightener appears as an unique boss. These five battles are notably tough for you're not allowed to use items (though the Yo-kai Blaster is still allowed). Also appearing are Mass Mutterer, Hinozall (both for the first time outside of Blasters), Hollow Guard in Zombie Night, Skulk in the Infinite Rice Fields, and Tornyedo (which is a palette swap and the father of another palette swap, Retinado) in a sidequest. The subsequent updates bring the Blasters T mode and several old Bosses, as well as adding some new ones as a result, such as The Goldfather, a new form of the Big Bad of the main storyline being the closest example to overlap with the Big Bad of Blasters T mode, as well as renditioning the third movie with Narwail and his second form Whaleman.
- Yo-kai Watch 4 does not have bosses like this in the base version, but adds Raidenryu as the most powerful opponent in the Yo-kai Sumo mode in the 1.3.0 update, who truly lives as his title as the Yokozuna of the Yo-kai World, since his Boss Battle still follows the Yo-kai Sumo rules and can be a pain to ring-outnote even with a team of three Yo-kai and a human player. Sproink and Hoggles return as part of the Blasters Mode, and Yami Ananta appears as part of a sidequest as of the PuraPura update.
- Yo-kai Watch Blasters has, successively, a haywire Robonyan 28 in the first half of the postgame, and Kabuking, Kat Kraydel, Hinozall, and Red Paws and Swirlious Omai (these two only being fought by sticking a total of 1000 friend insignias one-per-day in the YBA hall to the opposite statue in one version and playing with a friend with the other version). The Moon Rabbit Crew update adds several other bosses, with some of them being examples which are oddly close to being story Bosses: Captain Thunder, Robonyan 3000, Zazel/Zazelmare and his two retainers, also rendtioning the climax of the second movie, and Golden Claws, Swirlious Gold, Hinozall Awoken, Shogun King, which awoke due to the accumulated grudges from the Bosses which the Blasters defeated, and Pink Emperor.
- Yo-kai Watch Blasters 2 has Sasurai no Billy, which was the pirate captain mentioned in the backstory narrations in some chapters, and Majin Banbarayar, which also doubles as the endgame Boss for the Blasters' original objetive, as he grants a huge gold piece whose size depends of how the battle went, and is needed for the heroes to pay the huge debt Jibanyan had them contract and avoid the Blasters house being evicted. Yodelsen and Zircondor are other examples.
- In the JoJo's Bizarre Adventure Fan Game Your Bizarre Adventure, there are several bosses in the main game that do not need to be fought in order to clear the storyline. Several of them simply stand in the main map and can be challenged at any time (though doing so until the player has leveled up enough is not advised).
- DEO waits in the mountains, using The World against players who try to beat him and complete Dopey'snote side quest in the process.
- Joenote can be found outside the Naples train station. Fighting him is necessary to finish a side quest from DEO (who stands nearby).
- Joe Kujoenote stands in the ocean near the Colosseum in the main map. He puts up a particularly strong fight, boasting an evolved form of his original Stand and having a hefty amount of HP, but he sometimes drops an item necessary to get one of the game's most powerful Stands.
- Heaven Ascension DEO is the climax of Joe's own side quest, only achievable after gathering every part of the Saint's Corpse. Defeating the boss and his extraordinarily powerful Stand will rarely reward you with an item crucial to upgrading one of two Stands available to the player—either turning The Universe into The Universe Over Heaven (a copy of the boss's Stand) or G-Moon into The Way to Heaven (along with Joe's Disc).
- JoJo's Bizarre Adventure: The 7th Stand User has quite a few optional bosses, many of them only available on repeat playthroughs or depending on which ending you get. Diavolo also appears on repeat playthroughs, and if you choose to fight him, he has a chance of running away, so you don't get the money and EXP for beating him.
- Werewolf: The Apocalypse — Earthblood: At the end of the game, the player is given a choice between turning back to help Ava and the activists and pressing on to avenge himself on Richard Wadkins. The second option leads to a boss battle against Wadkins and his hordes of fomori.
Shoot 'em Ups
- Armed Police Batrider has a crapton of optional bosses, all of which appeared in the Mahou Daisakusen series and Battle Garegga. Said bosses include Bashinet, the Stage 1 boss of Mahou, and Black Heart, the Stage 5 boss of Garegga that, thanks to the stage edit feature, you can fight as early as Stage 2.
- DoDonPachi Dai-Fukkatsu has the six normal bosses of DoDonPachi (Suzaku, Senkou, Kakou, Raikou, Rankou and Ryuukou) as bonus mid-bosses, triggered by fulfilling certain conditions.
- In the PS2 remake of Space Harrier, continuing to fire at the end of Stage 19 results in the game continuing for four more stages, with twin fire dragons Haya-Oh awaiting at the end of #22.
Simulation Games
- Lots of missions in the Ace Combat games feature enemy aces whose defeat is not necessary for mission completion. They're not really harder than the compulsory aces. On the other hand, there is a more traditional one in Ace Combat Zero: The Belkan War: Mobius One and his Raptor are encountered in an Ace difficulty run of The Gauntlet if you do well enough. Similarly are Scarface One and ZOE Commander in a certain mission in Ace Combat X: Skies of Deception.
- Two optional bosses are available in the combat sequences-filled Dating Sim Mitsumete Knight : Zeelbis the Bloody and Salishuan the Spy of the Eight Generals of Valpha-Valaharian, the main enemy squad of the game. While not a storyline-related boss unlike the other two, Sparkster of the Rocket Knight Adventures series is also an optional boss.
Turn-Based Strategy
- Final Fantasy Tactics features an optional battle with Elidibs and the Zodiac summon.
- Fire Emblem:
- In Fire Emblem: Genealogy of the Holy War, in the Final Chapter, Arion is flying around with a squad of Wyvern Knights. However, the chapter can be cleared without ever fighting him, and he'll even become an NPC ally if Altena talks to him.
- Fire Emblem: Path of Radiance has General Bryce of Daein. Appearing in the last level of the game, Bryce stands in the centre of the map, astride the easiest path to the Final Boss, Mad King Ashnard. If you take him on and take him out, you can loot the most powerful lance in the game, the Wishblade. It is, however, entirely possible to avoid fighting Bryce by taking another route.
- Fire Emblem: Radiant Dawn has Levail, General Zelgius's apprentice and Bryce's successor as the wielder of the Wishblade. While Ike fights a Duel Boss battle with Zelgius, the rest of your team takes on Levail and his army. Defeating Zelgius is all that you have to do to beat the level, and the rest of your troops don't even have to move, let alone fight Levail (who, as a top-level Sentinel equipped with the Wishblade, is one of the few genuine threats you'll meet in the last quarter of the game). Many choose to engage him though, out of the desire to kill a few more opponents and maybe get their hands on the Wishblade.
- In the postgame of Yu-Gi-Oh! Monster Capsule GB, you can duel Joey, Tea, Tristan, Ryou, Grandpa, Pegasus, Bandit Keith, Shadi, Yami Bakura, and a freed Seto Kaiba. The latter two have the toughest monsters in the game.
Visual Novels
- Lux-Pain zigzags between regular optional boss and Skippable Boss. Most bosses have to be fought as part of the game, but some can only be encountered by following the right events (or even sequences of events) that only become available at certain points and lock again afterwards (hence the zigzag—there is no 'default' way through most of these sections, so whether you encounter them or not is just down to where you looked when you had the chance). This includes battles with the SILENT in the minds of Honoka, Sakai, and even Mint the ghost cat.
Non-Video Game Examples
- The World's Fastest Level Up: Marou Dungeon has a special boss that spawns if an Adventurer collects nine differently coloured magic stones along the way to the boss room.
