It's common in stories for good to defeat evil. It's reassuring, comforting, and satisfying. Sometimes, that's not an option, though. Evil is just too powerful, too well-prepared, and too embedded in the system. Rather than being able to turf it out for good, the heroes must find a way to live with it, negotiate with it, or simply escape it. This is not just about stories where The Bad Guy Wins - this is about stories where it was never seriously possible for them to lose.
This trope is common in several genres:
- Cosmic Horror Story: The protagonists' insignificance and helplessness in the face of the Powers That Be is the whole point.
- Crime Fiction: If the criminals are the heroes and law enforcement are the villains, then it's generally unlikely that our protagonists are going to take down an entire criminal justice system. Similarly, Film Noir's cynical attitude towards the law means the protagonists will often run into one of these, whether they be The Don, a Corrupt Politician, or a senior and well-connected Dirty Cop.
- Tragedy: One easy way for a protagonist's Fatal Flaw to destroy them is for them to get into a fight they really, really shouldn't have picked.
- War Is Hell: War is considerably less defensible as a concept if there's no realistic way for you to win, making this trope useful if you want to drive home how awful war is. Meanwhile, a Prevent the War plot gains extra menace if the other guys you're trying not to pick a fight with are both unpleasant and undefeatable.
An Invincible Villain will, by definition, be a Karma Houdini unless they have a change of heart on their own - at which point a Karma Houdini Warranty may be waiting in the wings if they experience a Redemption Demotion.
The Greater-Scope Villain will usually be one of these unless counterbalanced by a sufficiently effective Greater-Scope Paragon. After all, the whole point is that their victory or defeat is outside the scope of the story. On the other hand, not every Invincible Villain is a Greater-Scope Villain - the story can be all about how the protagonists deal (or fail to deal) with somebody or something they stand no chance of defeating.
Tropes Are Tools, and it's perfectly possible to write a good, satisfying story with an Invincible Villain, but there are plenty of ways to mishandle them. If taken to extremes, when the story is entirely about the villain constantly winning in some contrived way, this trope turns into Villain Sue. The Villain Protagonist is especially at risk to this. Stories that abuse this trope have a very high risk of Too Bleak, Stopped Caring.
Compare As Long as There Is Evil (where evil is vincible, but no victory can be permanent in-universe), Joker Immunity (where no victory can be permanent out of universe), and Hopeless Boss Fight, in which a video game player is faced with an (allegedly) unwinnable fight and has to lose in order to continue the game. Contrast Invincible Hero, their Good Counterpart, and Harmless Villain, their exact opposite in terms of threat level.
