The Big Bad as a Character
I don’t think that I would be breaking any new ground by saying that there are a lot of video games with antagonists. After all, conflict is the foundation of narrative, regardless of medium. Without antagonists, the Harry Potter books would have gone, Mr. and Mrs. Dursley, of number four Privet Drive, were proud to say that they were perfectly normal, thank you very much. And they were. Eventually they died. The end. Of course, antagonist has a rather broad definition- both the Dark Lord Sauron and the titular spaceship from Rendezvous with Rama can technically count as antagonists. All that matters is that the antagonist is a force that prevents the protagonists from immediately achieving their goal, and I defer any further inquiry on the matter to a literature class.
Most video games include antagonists, outside of purely abstract affairs like Breakout, and even in that case one could call the bricks the antagonist, if a rather unambitious one. Of course, like most stories, video games will sometimes try to make the conflict a bit more focused by attaching a face and a name to whatever malevolent antagonistic force is at work. The original Star Wars did this with Darth Vader, and Super Mario Bros. did this with Bowser (incidentally, I think that I’ve just laid the groundwork for the most bizarre fanfic crossover in history). However, problems frequently arise when we try to treat the face and name as an actual character instead of a this is what you’re supposed to dislike signpost. Bowser, despite being large and all, wasn’t a terribly interesting character in his earlier incarnations- he was just the last thing you killed before seeing the ending and deciding to play through the game again. Mehrunes Dagon from The Elder Scrolls: Oblivion is another, more recent instance of this sort of character: his only real role in the story is to A) set the events of the game in motion offscreen, and B) be defeated in order to signify that the game is indeed over. He has no dialogue, no character interaction beyond having his hindquarters presented to him in a most spectacular fashion, and, by extension, no personality.
The main reason for these sorts of characters lacking personality is that they don’t receive much screen time. While Star Wars can cut away at any time to show Vader plotting, giving orders, going through underlings like a hyperactive schoolchild goes through Skittles, etc., most video games are restricted to following around the player character. If the antagonist doesn’t show up around these characters, then he isn’t seen, at least for extended periods of time. This can be a problem when the main antagonist has something like Devourer of souls in his job description- it can be difficult to justify why this individual that you’re trying to give screen time is hanging around the player character without devouring their soul and prematurely ending the game. This can be justified once or twice, and a few antagonists can be fully and interestingly fleshed out in just that- see Sovereign from Mass Effect 1- but if you want to give them more exposure, it’s best to resort to alternative means.
One way to do this is to characterize the antagonist indirectly, using things like conveniently placed audio logs or written accounts. This allows the player to see more of the antagonist as a character, while also explaining why his soul is not presently being devoured. A suitably complex instance of this can be found in Oblivion’s precursor Morrowind, where it is through the virtue of in-game lore alone that the antagonist, Dagoth Ur, was made into an actually interesting character: all of the lore dealing with Ur is written from different, conflicting perspectives, each of which presents their own view of his motivations and personality. It is never made clear which, if any, of the perspectives is objectively correct, thus handing the player the information necessary to form an opinion about the character without handing a prepackaged opinion to them on a silver platter with a light garnish.
A more common approach is for the antagonist to address the player character through some sort of one-way means from a distant location, which allows them to react to the player character’s actions directly without being on-hand to end the game much more quickly. In Half-Life 2, one of the first things you see after getting off the train is Dr. Breen’s smiling face explaining why the human race being sterilized is so wonderful, and it doesn’t really get better from there. He pops up infrequently during the game, each time showing the player how he interacts with citizens, soldiers, and finally the player character himself. In Mass Effect 2, virtually every plot-important battle is punctuated by Harbinger periodically taking control (I refuse to say the meme) of one of his soldiers and shouting a few insults before being pulverized by a hail of gunfire. The fact that he not only keeps coming back, but never even loses confidence in his superiority, eventually gives the impression that this is somebody who A) is very powerful, and B) really has it in for you. In Fallout 3, the very first radio station you get a chance to listen to upon exiting the vault you lived in all your live is that of John Henry Eden, president of a group called the Enclave whose goal, as pontificated in length by Eden, is to rebuild America. Gradually, this stranger’s voice begins to seem like one of those overly friendly old men who sit next to you on the bus and tell you about the time they were served steak instead of fish at a restaurant. In the wake of the player actually seeing the somewhat morally ambiguous actions taken by Eden’s Enclave, the sunny tone of Eden’s speeches instead comes across as downright sociopathic.
Antagonists are often the most remembered part of a story. After all, while Luke Skywalker is nice and heroic, Darth Vader has become iconic to the genre of science fiction. It’s for this reason that, if you want to give an antagonist a personality, it’s imperative to do it well. A well-characterized antagonist can be the deciding factor in whether a game is merely good, or actually great.