Traditionally, Fallout games keep track of a player's actions using Karma. For doing something good, like giving a thirsty beggar some water, asking for no reward for a service rendered, or seeing how many rounds of ammunition one mob boss's head can hold, you get Karma. For doing something bad, like selling your friends to slavers, blackmailing merchants, and setting off a dormant nuclear warhead in the middle of a busy town because a neighboring town leader thinks the place is an eyesore, you get negative Karma. Your Karma score would influence various things, mostly the way that NPCs would react to you, your available options for a few quests, whether bounty hunters or mercenaries will eventually start hunting you down, and most importantly, whether potential party members would join you, and if so, which ones. It's a nice little idea that enhances the game's enjoyment and gives extra emphasis to the idea that your actions in the game have consequences by giving your actions overall some long-term results to accompany whatever immediate effects you've caused.
Fallout: New Vegas introduces an accompanying system in its installment, that of Reputation. There are several groups of influence and power throughout the Mojave Wasteland in Fallout: New Vegas, and what you do for or to them affects how that faction as a whole sees you, which in turn determines how they react to you and what quests and rewards they're willing to give you.
I like the idea in theory. After all, not everyone on one side or the other of Good vs. Evil should have the same values. If you get a bunch of Negative Karma because you can't help stuffing people's pockets with live grenades, it follows that a bunch of chaotic, anarchistic, crazy drug-users might react well to you, but a company of organized slavers probably wouldn't be all that impressed, even if both groups are on the Bad side of Karma. Having individual Reputation scores for each faction provides a chance for more plot relevance for your actions, making things more realistic, and also emphasizing the importance of the different factions to the Mojave Wasteland setting. Good idea!
Bad idea: relegating EVERY major effect traditionally associated with the Karma system to the Reputation system for the factors. They left Karma in the game, but it's almost entirely irrelevant now. First of all, there's barely ANY result of really high or really low Karma. The companions who can join you are dependent on your Reputation; the only one that actually cares about you being a psychotic mass-murderer is Cass, and she can be talked out of leaving you for your baby-eating ways, anyway. NPCs' reactions to you only seem to significantly change from Reputation--whether angels sing in your presence or you kick puppies with lead boots on, all any given NCR official cares about is whether or not you've been helpful to his country previously. Few NPCs have any biases beyond those faction-related. What quests are available to you are the same way--if there's any discrimination going on for whether a quest is offered to you, it's based on what factions you're friendly with, not whether or not you're a trustworthy individual in general. With few exceptions, the Reputation system has made Karma irrelevant.
Second problem: at least half the NPCs in the game belong to a faction, so killing them only affects your Reputation, not your Karma rating. So, hey, if you're not a fan of the New California Republic and want to serve another faction, feel free to open fire on a squad of unsuspecting NCR soldiers sitting down to have lunch. Sure, the NCR won't like you gunning down defenseless peace-keepers...but it won't make you a bad person, apparently! Now the only people you have to worry about killing indiscriminately are independent NPCs (which will give you bad Karma) and gang members (which will give you good karma). So if you actually CARE about what your Karma score is, your options for affecting it the way you want to are much more limited than they used to be. And who you're shooting at isn't the only thing that doesn't work the way it used to regarding Karma--while it was frowned upon in Fallout 2, grave-robbing is apparently A-OK in Fallout: New Vegas. You'd think someone in the town of Goodsprings would care that you're violating their grandmother's corpse on the off-chance that she was buried with a Stimpack hidden in her coffin, but nope.
And y'know, getting back to the idea that faction-specific kills don't influence your reputation, there's one aspect of it that I really have to say is ridiculous. Now, in the example I gave, you're killing a bunch of soldiers for the New California Republic faction in cold blood. Now, that's a pretty immoral act that you'd expect negative Karma for, but I can almost understand why you might not have a Karma penalty applied. I mean, it's hard to argue that the NCR isn't at least partially good, but they're very imperialistic, and even if they're bringing about a far safer, better form of life for the people of the Wasteland, they ARE doing it through fairly standard imperialistic military methods. You could be a good person and still disagree with the NCR's way of doing things, and support another fairly good faction instead. So even if it SHOULD be an evil act to kill such soldiers if they're not attacking you, I guess I can accept that it's associated with the act of opposing a faction that you could object to while still being a good person.
But the same Karma problem is present with members of Caesar's Legion! Kill a Legion recruit, and you'll only be awarded negative Reputation for them, but your Karma won't be affected. Now seriously...why the HELL do you not get good Karma for killing a Legion NPC? Come on. Other factions may have aspects of moral ambiguity, but you can't honestly try to tell me that a morally decent person could support Caesar's Legion. This is a faction that burns, pillages, and murders everything in their path, destroying every male it can't make one of its own, and enslaving every female as a supposedly inferior being. Sure, they exemplify militaristic discipline and abhor the drugs that run rampant throughout the Wasteland...but that discipline is savage brainwashing, and they act on their hatred for chems by crucifying anyone they suspect of using them. In fact, the Legion just crucifies just about anyone it dislikes for any reason--they're big fans of horrible, tortuous public death. And hey, might I again mention, ENSLAVING HALF OF THE HUMAN RACE. Being sexist asswipes convinced of the inferiority of women in all things is bad enough as it is--using that philosophy to enslave all women to serve all their labor needs is amazingly evil. I'd say it's worse than just having normal slavery, but slavery is already the absolute polar end of the moral spectrum in my mind, so I guess it can't actually get worse.
So, essentially, Caesar's Legion is a group that combines the cruelties, barbaric violence, and dogged imperialism of Rome, the brainwashing power of the Third Reicht, the empire-built-off-slaves part of Ancient Egypt or the deep pre-Civil War US South, and the gender philosophies of...well, pick just about any society and go back a little ways to the point where women had absolutely, 100% no rights and were considered inferior in every way. Some cultures won't require you to turn too many pages of history back to find it.
Can someone PLEASE explain to me why feeding a Legion member a bullet breakfast does NOT give me positive Karma? Is there REALLY any moral ambiguity associated with this faction that could reasonably lead a good person to support them?
And when I ask for explanation, I mean a REAL one. Not the lame-ass failure of an excuse that's been going around, claiming that since Caesar's Legion is using all these terrible, evil acts toward the goal of creating, maintaining, and spreading a form of civilization, it falls into a neutral zone for morality to the Fallout universe. No. That is fucking stupid. Maybe if Caesar's Legion had been a faction existing early in the series, like within the first few decades following the world's destruction, that claim could be made, because at that point, there really wasn't anything anywhere resembling civilization that I know of, so perhaps seeing the Legion as the ONLY alternative to chaotic, violent, deranged anarchy would have been able to make it a "neutral" kind of choice. Maybe. But in the setting of Fallout: New Vegas, having the Legion be considered anything but brutal, heinous evil is, and I can't emphasize this enough, fucking stupid. Because by that time, that area of the Fallout wastelands has got the New California Republic as an option for civilization, and Mr. House, the New Vegas families, the surrounding towns, and the various smaller factions ALL present viable opportunities for civilization. You're not choosing between Caesar's idea of civilization or none at all. You're choosing between one legitimate form of civilization (the NCR), another conglomerate of legitimate civilizations (the towns and factions of New Vegas and the surrounding area as they already exist), or a form of civilization that finds honor in brutality, enslaves half its population for a condition they can't change under false claims that it's inferior, and delights in monstrous torment. So saying that Caesar's Legion could be considered a "neutral" moral choice in any way for the setting of New Vegas is so arrogantly short-sighted and reeking of idiocy that I wish I could hit each and every person who makes that claim in the mouth so hard that they'll look like a checkerboard the next time they grin.
Anyway...I think I've gotten a little off-topic. Back to business. There are many good innovations with Fallout: New Vegas, and the Reputation system works very nicely by itself, but they really just dropped the ball completely on properly incorporating the traditional Fallout Karma system for New Vegas. It's so totally insignificant to the game's entirety that it might as well not even be there, and the developers were so obsessed with making the faction Reputations a big deal that they created a separation between Reputation and Karma that at several times, like with the Legion somehow not being considered evil, seems outright stupid.