I'm starting to get into the character design of my game now and I'm wondering what makes a cool bad guy for a game? Obviously it's different than other presentation methods like movies and novels. What works for a bad guy in a game? The evil villain who kidnapped the hero's girlfriend? The crime boss who needs a good beatdown? The evil sorcerer who is trying to rule the land? And for that matter, what makes a good hero? Does the hero have to be the antonym of everything the bad guy is, or maybe the hero does a few bad things along the way? What are your guys' thoughts?

If bad or good character, the main question is still what makes a interesting character ? In my opinion the development of bad guys or heroes changes in the last decade(s).

From the pure heroric or pure evil version to a more "grey" version. What I mean is, that most "interesting" characters in modern medias aren't really purely good or evil, but trying to balance on the small border between good and bad. Take a look at movies, tv-series (i.e. dexter) or games (i.e. bioshock).

That are my thoughts, but I can't pin down "that" feature what makes a good character design.

Good character gone bad, and must be redeemed or slain, but the player feels guilty and can't pull the trigger. 3rd party comes in and goes 'Do it! Or he'll kill us all!'. Used quite alot but not quite at cliche stage yet. More a trope :P

Mislead holy crusader of corrupted ideology.
Or
Depressed sage of common good.

There is no simply good or bad, it`s only about story that is told.

/Tyrian

What makes a good bad guy (Typical from the 80s, 90s movies), is beating or killing his own minions when they fail, or for no good reasons. Like in desperado when his men fail to catch the Hero, he randomly kills one of them by saying he looks "suspicious".

Personally I believe that the most successful protagonists (or antagonists) are ones that are neither particularly good nor evil, but have their own reasons for their actions, both sides considering themselves "good". This is easy to use , opens up many doors, and is difficult to make cliche.

One good example is the part of the tales series released for the gamecube (cannot remember its exact name). The "villan" in this game was at one point in history the hero of the world. He is simply trying to revive his sister who suffered an unfortunate fate.

Other examples to look at include Cid from FFXII (who wishes to give the world back to man rather then the "gods", dante (from dantes inferno) who commits evil to save his loved one locked in the depths of hell, the "evil wizard" from boulders gate 2, who is attempting to understand death so that he can bring back a loved one. The latter parts of the Brionac Forces in Wild Arms 4, who (while acting as the main protagonist force to the hero) are actually trying to save the world in their own way, and consider the hero a hindrance.

Just some things to think about

Edit: this type of antagonist/protagonist is particularly important in games, as it helps drive a story through character development easily. in the beginning, it may seem like these people are the bad guys, and you come to learn slowly that they are good. or you could even explore this area the opposite way around.

I want to say though that there's more to a good villian/protagonist than just having "grey" motives. Such as I don't really feel any connection with Dante in Dante's Inferno, because the gameplay never reinforces the character or spends time to build it. I'm just told this is what I must assume for this guy while in reality I just kill a bunch of stuff because that's what the game tells me to do.

This is where character development is important - they grey areas area great but they only work if there's a connection that is made to the player. If the player doesn't care about a character or the character is only presented and developed as some transparent backstory and nothing else, then Dante ceases to feel like Dante and instead becomes "knight guy with jesus cross attacks".

Not saying Dante's Inferno failed because Dante wasn't developed as a character, because the game wasn't designed with plot immersion in mind (for better or for worse some might argue).

The villain is inherently connected to the hero. A paragon of truth and justice would have a villain who was the opposite: uncaring and self-serving. A hero who lives a world of grays would have villains who similarly exist is worlds of grays. Heroes like Superman are great because they don't have to make moral choices: they exist in a world where they can only do right. Characters like the Punisher, on the other hand, have villains with clearly human motives; they need money for an operation on their sister daughter, etc. The best villains are foils for the hero. I would decide on a hero before the villain.