AI. NPC’s. Enemies. The majority of games do not put players into a truly solitary environment, rather favoring interaction between the player’s character and characters, and this usually involves interpersonal conflict. It’s important for designers to figure out ways to engage the player when working against these foes, because otherwise a main source of conflict would be moot. The creation of a solid antagonist really requires three main considerations; narrative, mechanics, and presentation.
In any game defined as good on account of its story rather than merely its gameplay, enemies have a narrative consideration. This really can be broken down into three core elements; motive, place, and role. The motive of a character, obviously, will drive them and who they are-Iago’s racism and misplaced grudge against Othello are core driving elements of his character, and make him a much more hated villain than he would be if he’d simply flipped a coin and decided to ruin Othello’s life. Consider what an antagonist has to gain from attacking the player. If they’re consumed by hatred and rage, they’ll be a lot more dangerous but also blinded by fury, while a character who’s just on the lookout for a guy in a suit and tie in order to earn a paycheck may think twice when it turns out that he’s about to get shot in the face by a secret agent. For an AI designer, this might look like making enemies flee or surrender if they expect to be killed. Another degree of immersion could be added by suppressing the chance of surrender should the bad guy’s allies have been gunned down without mercy. The Tomb Raider reboot has an interesting take on this; the bad guys are cultists and believe that one of Lara’s friends is the key for them getting off the island they’re trapped on by supernaturally horrid weather, and they’re willing to kill or die for that chance.
The place of an antagonist, on the other hand, really revolves around when and how they will encounter the character. Comedic antagonists, such as the quirky miniboss squads often used in JRPG battles, often fall short of the top of the food chain and are used as preludes for harder fights. Even the clerk at the DMV can be a suitable antagonist, should they choose to be a stickler about that one little piece of paperwork the player’s character left at home. This is also what will decide whether the antagonist is necessary for the protagonist to overcome (or even encounter). For instance, wandering into a bear’s den creates an otherwise optional, but very angry, antagonist. If the antagonist is just a minor character in the game as a whole, consider how they relate to the player. Remember that place does not necessarily equate to screen time; the faceless head of a megacorporation can be pulling the strings and moving resources into action against the player without ever being directly involved in the narrative to the player’s knowledge. Remember, however, that antagonists gain much of their appeal and emotional power from their first impression, especially if they’re supposed to die in the fighting, and should be introduced when best-the executive I mentioned above can have his name dropped on a memo carried by a hitman (seriously, professionals are hard to find in video and tabletop games).
Finally, an antagonist has a role to fill. Consider how they play into the story outside of their encounters with the protagonist. The guy who killed the player character’s wife may have had it be the defining moment of his life, the one thing he can never atone for that drives him to madness even though his lawyer got him off the hook, or he could be a hardened mafia boss doing his Tuesday chores. An antagonist who has a huge role should have their downfall reflected in the narrative. The exact impact of this is up to the writers and developers to consider, but if you give Hugh Canon a grudge against the President of the United States (or the head of MJ-12), you’re probably going to have it make the headlines (or be kept a state secret) and have global political impacts when Hugh gets his violent, bloody revenge, If your narrative will allow it, make sure that the antagonist’s death has impacts in the story (or even the mechanics) beyond the gameplay; if the Manaspring Guardian became possessed by the dark abomination from aeons past, killing it could irrevocably change the way magic works in the setting. I’m not going to say that games invariably have to have a message about the destructive nature of violence, but an antagonist works best when their downfall has consequences; Wolf #6 that attacks the protagonist as they wander through the forest doesn’t have to matter, but if Possessed Townsperson #2 has a wife and kids it’ll force the player to accept the consequences of their actions.
Mechanics are also important. I like to think that there’s four types of enemy, the Crushing Villain, the Climax Villain, the Obstacle, and the Padding. Crushing Villains, as their names suggest, are introduced as a more powerful enemy. They can be used as “meat gates”, essentially area-denial resources that make a much better narrative or setting than simply walling off an area with an invisible or unbelievable wall, such as sharks in Far Cry, but they can also be used to serve a narrative point. They can, potentially, be beaten, like the boss in the introductory tutorial to Dark Souls, but they’re not meant to be beaten at the point in the narrative in which they are encountered. They can, obviously, transition into lesser roles, but this should be used with care, because of the potential narrative issues with changing known characters’ mechanics or the mechanical issues of player character escalation, but this isn’t necessarily something that is always a bad thing-if it works better for your narrative, or if your game will support the growth of player input skill or character power to meet the challenge, a Crushing Villain changed into a Climax Villain or even an Obstacle can become a very poignant challenge. A Crushing Villain can also be used, sparingly, for a cheap kill. Having an important character (preferably with emotional investment attached) killed by a zombie bite in the middle of a post-apocalypse creates a Crushing Villain from an otherwise normal foe, as can having a sniper take out a member of the player’s squad or having a bureaucrat misspell a name on an application and drop the protagonist on the No Fly list.
A Climax Villain is typically encountered at the peak of the hero’s endeavors; whether as a “boss” enemy at the end of a game’s act, chapter, or important scene, or as a final climactic villain at the end of the story’s narrative, they’re a significant challenge provided to the players to get them to show their skills or otherwise feel good about themselves. A lot of games turn these foes into quick-time event fights, which can work but it’s important to consider whether it’s a method of improving the narrative, working outside the existing mechanics, or being cheap. From a narrative sense, sometimes you’re better off if you present scenes through a framing that doesn’t support your normal gameplay, for instance, if the protagonist is fighting for a parachute while falling through the air in the middle of a fight with his nemesis, you probably won’t be able to work in standard FPS mechanics, so this is an okay place to put a quick-time event or an alternative gameplay method if you have the resources for it (first-person fistfighting, for instance). If your mechanics won’t support a boss fight (for instance, Tomb Raider’s are dubious in this regard), you may want to go into a quick time event just to keep things interesting, because if you’re fighting a normal human foe who should logically go down in one shot when he’s shot in the head and isn’t wearing armor, it’ll work better to distance players’ honed killing machine shooter skills from the final bossfight. Don’t use a quick-time event just because other people do it, or because you don’t have assets for a bossfight. Switch to a simple cutscene instead, or integrate it within the normal gameplay. Far Cry 3 was panned for using a QTE when its core gameplay could have been integrated fine, and Resident Evil 5 made itself even more annoying with QTE’s. Dishonored, on the other hand, actually used its normal system for climactic fights, and didn’t suffer at all on account of it, despite its normally flighty and uninspiring combat.
Opponents are common foes that will cause the player a little bit of angst, but won’t stop them. Be sure when designing an opponent that they won’t entirely ruin the player except, perhaps, in the narrative sense (i.e. the DMV worker in an earlier example). They should be easily overcome by simply finding an alternate route or choosing the correct skills to overcome the challenge. Any character who is not named (or fleshed out, in the case of anonymous antagonists) should fall into this category or the Padding group. The zombie who sneaks up behind people and knocks them into a pit in Minecraft would fall into this category, as would the creeper who blows up half their house. These foes are non-insignificant to the gameplay, but are typically part of the narrative only in a loose sense.
Padding, on the other hand, is the foe that nobody needs to worry about. They’re the goblins, gremlins, lesser lesser demons, angry dogs, rotting zombies, and rats that are ubiquitous in gaming as the foes that are used either as fodder for a leveling mechanic or as a way to show off the protagonist’s skills. Consider the fact that these characters are almost never, at least on an individual level, mentioned in most narratives or get more screen time than saying “Where’s Steve?” as the protagonist stealthily knocks out everyone in the base and dumps them into bathroom stalls, or as victims of the “good guy”‘s homicidal tendencies. If they’re on-screen for more than fifteen seconds, they’d better be outside the player’s reach or you may risk frustration as the player feels that they’re repetitively fighting time-consuming foes that can make up the majority of the game’s screen-time (consider Dynasty Warriors here; the enemy army’s soldiers don’t take nineteen hits to take down).
Also mechanically, consider how antagonists work. AI should refresh often enough that they’ll respond to players, and they should be given power sets that work against the players’ abilities. Enemies should be designed to fit into gameplay; it doesn’t make sense for Mario to fight foes that go exclusively underground, and mechanically it helps if players and enemies share certain features, but this should not overrule their function as obstacles and narrative devices.
A lot of game designers make the mistake of viewing the player and their enemies as needing to be inherently symmetrical. Skyrim, for instance, had a huge potential to turn dragons into really frightening and majestic opponents by making them use their flight and shouts to the best extent; in practice this didn’t pan out, since dragons behave like human foes with a height advantage and even abandon this to attack the player in their worst possible environment; toe-to-toe fighting on the ground. Compare this to the free shooter Tremulous, in which an alien and human faction fight; the aliens have certain methodologies that they can use to their advantage, including speed, the ability to walk on walls, cloak, and more. Asymmetrical challenges can be more engaging, and make more sense. Sometimes this means that you’ll move away from your standard gameplay methods and do something more like Shadow of the Colossus which does not treat certain enemies as traditional “hit it with your sword” foes.
In addition, consider your player’s experience when encountering your foes. If a trick is needed to beat them, you may want to inform the player of this or you’ll risk frustrating them. If a foe is unresponsive to a player’s action, they’ll disengage; in Legends of Aethereus, I’ve watched foes walk right past me as I was trying to line up a crossbow shot; foiling my point-blank shot but also being incredibly broken as they passed to four feet behind me and then began to swing at me. Needless to say, this is somewhat immersion breaking, and also feels incredibly shoddy.
Finally, presentation makes an antagonist. Tomb Raider did a really good job of setting the player up to see foes, even unnamed foes, in situations that biased them in their interpretations; one knows their enemy is a depraved murderer when he has a skull throne, and there’s blood all over the place. Enemies fleeing a burning city, on the other hand, are almost sympathetic as they are terrified and demoralized, posing little threat to Lara. Sephiroth would just be a whiny guy with long hair if he didn’t murder Aeris, and Handsome Jack would just be a jerk if he didn’t kill so darn many of the original Borderland’s characters both on and off camera.
Central antagonists are all about framing; the burning village has been a cliche of sword and sorcery or more modern action genres for decades, but works well because it provides a great way to show how horrible the big bad guy is. If you want an antagonist to be comedic, they can attack the player in the middle of a public area and get beaten down by a good Samaritan in the crowd. Scale and lighting work well here; Burke’s principles of the sublime turn an otherwise meaningless villain into a major one. Alternatively, it’s possible to do the contrast villain, who, in the middle of a beautiful scene, decides to do something absolutely horrifying and objectionable.
In addition, consider the role of antagonists in the story, and work their motives into their presentation. The criminally insane cultist may hate the protagonist for disrupting the “grave” of his “mother”, and proceed to scrawl obsessive rambling messages all over the walls of their dwelling before going out with a hatchet to enact revenge.
The single element, however, most important to the story’s antagonist, is that they must throw a wrench in things. Players must, ultimately, reject them and what they stand for, whether they are a villainous scourge, a misguided seeker of what they perceive to be good, or a genuinely likeable character whose actions cause destruction. Sometimes, the antagonist may turn out to be a pawn, the good guy, or even the protagonist’s past self, in which case they can be turned into a tragic figure or the protagonist can be turned into an anti-hero, but in very few cases can the antagonist be accepted as is; they must reform or remain in conflict with the player. They cannot merely “exist”; the dragon guarding his lair is not the villain, while one who has kidnapped a prince(ss) or taken the Dwarves’ hall as his own is.