Personally I think it's fine if the player violates modern moral standards because DF doesn't take place in modern times. I doubt we'll make any progress on that front so agree to disagree.
The player is playing the game in modern times.
Again I have a problem with this attitude and I doubt either of us will change the other's mind. Simply washing my hands and saying "not my fault, not my problem" is not acceptable for me.
The alternative is really not a functional system. The reason is that there are a far greater number of things that we could all be doing with our time than we actually have time to do. While you are killing the world's dragon, it's hydra is somewhere else also killing people and there is an injured person in the middle of the wilderness somewhere that needs rescuing and so on. That cinches the whole moral dilemma thing, doing bad for good ends generally fails because there are other good things you could be doing.
That is why I think that your societal responsibilities matter ethically. If you were made the official dragon-hunter of some civilization, promoting slavery in some other civilization becomes a genuine moral dilemma as it were and I think the calculus is then actually on the side of you killing the dragon. Your responsibility is to save people of your civilization from being killed by dragons, not to keep other societies from being slavers.
Who you are, where you are and what you did in the past matter in my opinion.
You are correct. Most of the roles you would play would force your adventurer to "play by the rules", and changing those rules would be very hard. I agree that doing it any other way would do a disservice to human history's long, hard-fought struggle for the civil rights people in most 1st-world nations enjoy today.
Also, the society doesn't think what it's doing is actually wrong. When a society thinks something it's doing is wrong, given enough time, it stops doing that thing. Societies are setup and maintained by benevolent people for the benefit of benevolent people. Malevolent people exist, but given enough time, they are always ousted or shunned from the society. A long time ago, executing prisoners was the norm. In that society, making prisoners slaves would be considered "benevolent". Today, thanks to liberal and enlightenment thinking, we view it as morally reprehensible.
Suppose by the time DF is made a complete game society decides raising and consuming animals for food is morally wrong? Should that still be included in the game? (and yes I acknowledge there's a difference in that one of these things is already in the game and the other is just a proposal; I think it's still worth exploring the question)
The game already has a society that has decided that raising and consuming animals for food is morally wrong; the Elves. But they don't attempt to impose that on anyone else, generally, nor does the game currently give them the tools to do so.
One issue is that what is wrong/right is not in most societies the same thing as what is legal/illegal. A society can permit people to do things that it considers wrong. That is what complicates the whole story of societal reform, you have to deal not only with those who think that the societal evil is not wrong but also those who agree with you that it is wrong but do not think it ought to be prohibited all the same.
I don't think it's relevant whether it's moral to hunt the slaves to obtain the amulet to kill the dragon to save the people the dragon would have killed. It's a lesser-evil scenario, and the player has to decide which evil is lesser. It's good gameplay - open-ended and a roleplaying opportunity. You can establish what your character is like through their actions. It's even better if their actions shape in-game reactions by and interactions with different characters.
The problem is not the moral dilemma, it is that if you kill the dragon you advance in the game, regardless of whether it is the right thing to do while if you refuse to kill the dragon you don't advance in the game. Games are biased towards winning, that is advancing the character's story in the desired direction, that means when a moral dilemma occurs the game simply makes the decision as to what to is the correct thing for the player by virtue of how it is structured, semi-randomly in this case.
The problem as already mentioned is that is exactly how real-life societies control their members dissenting tendencies; I call this the win-lose matrix. Above right and wrong there is the imperative of win/lose. The society gives rewards to those who behave the way it wants them to behave, in other words they win and hands out punishments to those who dissent, in other words they lose. An evil society is challenged and forced to change when people refuse to value it's rewards and value it's punishments.
In a computer game however, the entire thing is just a win-lose matrix. In effect the gamer is the perfect subject for societal indoctrination, that means that fictional societies are indoctrinating the player to think as they think in the same fashion real societies do.
(Personally, I'm a utilitarian, so I'd weigh the positive and negative effects of the slave-hunting-and-dragon-killing plan. Pros: people saved, safer world in general (safer to travel means more trade etc.). Cons: slaves are worse off, and I'm stabilizing the institution of slavery (making it more profitable). Then I'd come up with other plans (steal the amulet, come up with other ways to kill the dragon, storm wherever the amulet is held and free the slaves while acquiring the amulet) and compare the net expected utility of each plan. My character might do something different, however, based on my gamestyle or role I'm playing.)
The irony is that a computer game is probably the only environment where such ethical calculations can actually be made. But the computer game makes all the calculations for the player, the right thing is always to win and the limitations of the game mechanics limit the ways you can win. Your maths will never be allowed to produce an outcome that the right thing to do is to lose the game.
It's okay if you are allowed to do immoral things in the game. It's okay if your character (directed by you) does something you'd disagree with. It's okay if your character does something I'd disagree with. The simulated people have no moral value. You're not harming anyone. You can pretend to have a different morality without breaking your real morality. That's a good thing. It lets you imagine being somebody else. It's enjoyable and can generate novel experiences that you can't safely get elsewhere. And novel experiences can be useful and help you understand others better. Most people you disagree with aren't intentionally evil, for instance. Some people don't understand that, or only understand that on a surface level. Pretending to be different could help with that.
It's okay - even good - if there's no clear right answer, and we're forced to confront the contradictions in our moral frameworks or choose one value over another. That's not just a good game, that's a *thought-provoking* game. And if you don't want to think about it - don't. You won't harm anyone if you take the immoral option, since it's not real.
In a nutshell: games aren't better when there's a single Right Thing To Do. It may *feel* better, but it's unrealistic and doesn't produce complex gameplay. It's like if you could kill all the goblins with a single button.
That would be all fine and good, *if* we lived in a perfect world in RL. As I said before, societies (fictional or otherwise) primarily control their people through the win-lose matrix and a computer game *is* a win-lose matrix. The most easily controlled people in any society are those who live their lives as though life were a computer game, their purpose is to get ahead in the game and if they fail it is their fault for not learning the rules properly.
What happens if our computer game ends up replicating some oppressive societal system that actually exists? Now our win-lose matrix mirrors that of the society we are part of. Since it is now in effect functioning as propaganda for the societal system that is it's mirror in RL, real people are actually getting hurt.