They say that size doesn't matter, skill does. This is more true of the softer arts which use an opponent's strength and momentum against them, but still true of striking arts. However, there's a reason why there are weight classes in almost every competitive martial art (wrestling, boxing, Taekwondo, MMA, Judo, Muay Thai, etc). There's also a reason why house cats hunt mice instead of buffalo. So, expanding this into fantasy and science fiction, I'm curious what's the point in which you shouldn't even bother? I'm looking mainly into two categories: Monsters with super strength relative to their size Monsters with super size (and by direct result: super strength) Super Strength This could be simply beings that are more powerful than a normal human of the same size, such as Superman (let's take a really conservative version of him), Terminator, Goku (let's take an early Dragonball version of him), Predator, or Captain America. How well would martial arts work in these cases? In the case of a super-strong mortal, particularly someone like Cap, is there a point where the strength gets to be too much to overcome? Specifically regarding the Terminator, would Judo or another throwing art work on a cyborg? What about hapkido or another joint control art? Super Size Let's take a fight between a human and the 2014 Godzilla. Ok, bad example. The human obviously can't do anything. How about a human against something more tame, like a velociraptor from Jurassic Park? I'd have loved to see Jackie Chan or Jet Li kick in the face of one of those things. In more seriousness, what is the point at which a monster, which is proprotionally similar to a human, becomes something a human shouldn't even bother fighting? Is it something 8 feet tall? 10 feet? 12? What's the cut-off point where it goes from "ridiculously hard boss fight" to "victory impossible" to "this thing doesn't even feel my punch"? Scaling Taking the super-size question a step further, does this ratio change as things get bigger or smaller? For example, if we decide that something 10 feet tall is the limit for a 6 foot person, does than mean a 30 foot person can fight a 50 footer? Or does the extra size mean the size difference must be closer, or can it be further apart? Going the other way, what about someone who is a third of an inch tall against someone a half inch tall? As you get smaller, how does that affect the ratio (or does it affect it at all)?