I think it's fair to say that the majority of table top role playing games operate under the assumption that the player characters are the good guys.
I don't know that that is true. I think maybe even a minority of players operate under the assumption the characters are the good guys, and of that minority in my experience the majority of them are wrong. Actual good guys are as rare in RPGs as they are in the real world - and quite possibly much more rare.
But now that I've typed that out, what does it even mean to be the good guy?
And that's the problem. Most people cannot adequately answer that question. IME, the average D&D character (to use a common marker) is one step more evil than his player believes his character to be. Maybe 1/5th of the PC's in the games I've run over 40 years were actually 'good guys' and they were generally fighting a losing rear guard battle against the rest of the group's amoral, savage, and ruthless tendencies.
For the purposes of this thread, I'm going to define good as leaving things better than you found it without harming innocent people.
That's actually a pretty strong definition. I'm surprised, as quite often I don't see people able to elucidate what good is as clearly as that. I have quibbles with the definition, but it's a very strong understanding of what good is and better than what you find in much of WotC's writings.
You might argue that Roy Batty was a dangerous murderer, but a slave rising up and killing his oppressors is perfectly natural in my book.
It is perfectly natural, but does it meet your definition of good? Roy's motivations are sympathetic, and he has legitimate grievances and you can empathize with Roy - but does that mean Roy is good or that Decker is wrong for being assigned to hunt him down? Roy's actions aren't always in fact acts of someone commiting necessary violence to earn freedom from oppression. Roy has grievances he wishes to bring against his creators, but when he meets individuals like J.F. who is partially responsible for his creation he finds an autistic savant who is highly sympathetic to Roy and hides him and protects him and even helps him achieve his aims of meeting his 'creator'. J.F. loves Roy as best as he's able, and he's betrayed and murdered by him. Does this meet your definition of good?
And here we come to the problem. You knew what good was, but then when you looked at a situation you didn't evaluate it according to your own standards but instead evaluated it according to conventional analogies and standards and your feelings. Do those analogies really hold up? Is it really true that just because they are almost human that they are human? The book and the movie come to very different conclusions about this. The answer isn't a given and has to do with things like empathy and free will. And even if the analogies do hold up, there are few beliefs quite so evil as "Because I have been wronged, I have moral authority and can do whatever I want to avenge that wrong." That belief gets you something indistinguishable from the philosophy of the Nine Hells.
One of the great things about Blade Runner is that it's a story where no one is entirely a good guy or entirely a bad guy, and at the end of the story Roy has a bit of an epiphany about that and undertakes to redeem himself - gaining as it were a consciousness and a soul, symbolized by the dove he is caring for at the end of the movie.
What other games are there were the PCs are bad guys by default? Feel free to disagree about whether the PCs in Blade Runner or Vampire are "bad guys" if you'd like. I can't control you guys and it'd be foolhardy to try!
I would tend to say that in most games the PC's are bad guys by default, and the PC's have to work really hard to actually be heroic - and most players aren't really interested in being heroic. Indeed, I could derail the thread here with a very strong version of this statement, but IME most tables in most systems are villains. Most of them use some version of the reasoning you applied to Roy Batty to suggest that 'my tribe vs. your tribe' and 'my tribe is good' is sufficient to justify the goodness of the PCs no matter how murderous of murder hobos they are, and unlike Roy, they don't ever seem to realize the tragedy of being a murder hobo.
A better question might be are there games that do a pretty good job of encouraging the players to be heroic and good by your own definition of it? For my answer, I'll say that 'Call of Cthulhu' rather surprisingly comes up with a framework for ensuring players will tend to be heroic and that is by the simple and well trodden trope of making sure the bad guys are so utterly horrible that anything the PC's are doing to thwart them could be considered leaving the world a better place. When you are facing cosmic anti-human horrors that threaten all of existence, there is very little you can do that can't be justified by the ends justifying the means, but further that for all the immorality that shows up in published CoC adventures rarely are the players forced to do something morally compromising in order to win the day. The worst they are often asked to do is sacrifice themselves for the good of others, which generally meets the definition of heroic.
