A type of AI opponent in a Fighting Game who breaks the rules that enforce Competitive Balance to such an absurd degree that they are considered to be vastly superior to every other character in the game. The SNK Boss combines Nintendo Hard with The Computer Is a Cheating Bastard and takes them Up to Eleven. Powers may include:
- Complete Disregard for System Limitations: While you may have to switch between high and low blocking, the SNK Boss needs to only block one way. Where you have to crouch or be in a specific position to perform certain moves, the boss does not. When certain attacks require charge motions, the boss can throw them out rapid-fire. Where you have a regular super meter, the boss either fills its super meter much faster than yours, has a regenerating super meter, or in extreme cases has no visible one, meaning it can use as many supers as it wants whenever it wants.
- Blatantly Overpowered Offense: A trademark of the SNK Boss. Where you have fireballs, the boss has full-screen lasers that come out faster than you can blink, deal damage equivalent to 1/4 of a health bar (and also deal about a third of that in chip damage if you block it), and snuff out all other projectiles. If you have an invincible uppercut, the boss likely has one where he surrounds himself with lightning for more hits and damage, and can cancel out fireballs. They also likely have lots of unblockables, in addition to doing lots of chip damage, having confusing or difficult-to-block attacks, frame advantages no matter what you block, and deal tons of guard damage (and possibly have at least one instant guardbreak). If you get past the first round, the second round is vastly worse - they may enter permanent rage mode, automatically start with full super and/or EX meters, gain brutal new attacks, or otherwise go from rough, but doable to absolutely ridiculous. These types of bosses sometimes, but not always, have a maximum level super where they show off their superiority by utterly annihilating you regardless of your current health, usually combined with Fingerpoke Of Doom for maximum insult.
- Blatantly Overpowered Defense: They may be the gameplay equivalent of The Juggernaut, being able to continue their attack startup against your own hits or possess features like a larger health bar, reduced block-stun, inability to get dizzied (or a shorter dizzy period), inability to be guardbroken (or have a guardbreak meter that fills up so slowly that they may as well be), immunity to chip damage, extremely fast grey health regeneration, or they can interrupt your combos with their attacks (oftentimes via super armor), escape from a juggle via some sort of recovery/teleport, or even be completely immune to some of your attacks (such as grabs).
If the boss is playable, such as upon defeat or paid and hired, they are significantly weaker and more balanced for actual play. A non-weakened playable SNK Boss is most certainly banned in any competitive tournaments where it would be a Game-Breaker for one human player to use on another.
In some fighting games, the Final Boss is a unique opponent in both design and ability (such as a 30-foot Eldritch Abomination) that is Purposely Overpowered and only appears in single-player/non-competitive game modes; it's slightly more sensible that such a boss would have those high-powered attacks rather than a human-sized villain. It can also feel pretty good for a player who manages to use an otherwise-mortal badass to beat the crap out of a godlike monster.
These bosses originate from the days of arcade machines, where the high difficulty level was used to separate players from their pocket change while attempting to register their initials in the top spot of the machine's High Scores table. In console games, side effects of continued exposure to an SNK Boss may include broken controllers and increased sales of GameSharks to "cheat back". Occasionally, these bosses may have an Achilles' Heel that utilizes special moves from characters that usually have limited utility. It is unknown whether these are intentional or not.
In cases where SNK Bosses are unlockable via real money, the players are willing to spend extravagant amounts of money to get them. Such practices led to the new variation of this trope, $NK Bossnote .
Is there an upside to this? Gameplay and Story Integration. Given that characters of this kind are frequently talked up in the story as being terrifying and powerful, if they fall into this category then at least the player doesn't feel like all the hype and drama was over nothing.
Takes its name from the company SNK, which seems to love making bosses like this and having each successive one top the last. This is also a case of Follow the Leader, especially with Arc System Works.
While this trope primarily applies to fighting games, it can also apply to non-fighting games, provided they are similarly competitive and have similar ways of ensuring Competitive Balance. A Racing Game, for example, may have a champion with an absurdly tricked out car and a knowledge of the track that combine to give it an advantage no matter which vehicle/racer you choose.
Note, SNK Boss is not a catch-all term for an overly hard, cheap, or even mechanically unusual boss. It's the way the boss breaks the *competitive* balance of a largely *competitive* game that makes it an SNK Boss. By definition, bosses of largely single-player experiences — RPGs, Platformers, Stylish Action, etc. — are not SNK Bosses due to those games being non-balanced by their very nature.
Subtrope of Fake Difficulty and The Computer Is a Cheating Bastard. See also Perfect-Play A.I., whose difficulty arises less from outright cheating, and more from a flawless battle strategy. Do not confuse with That One Boss, which describes a difficult boss as declared by a majority and technically fights on a much fairer level when compared to this trope. See also Easy Levels, Hard Bosses. Don't be surprised if they can only be toppled via Not the Intended Use, chiefly AI Breakers.