Balancing Intelligence and Agency: The Secret to Engaging Game AI

Video game monsters like Troll make games fun

The only thing more aggravating than playing a co-op game with somebody who can’t keep up with you is playing a game with AI that can’t, either. A poor real-life partner can at least be taught—you can ask them to pick up the pace or show them how to play better—but an AI partner is stuck with whatever skills they’re programmed with. Good game AI is hard to find, especially because what defines ‘good’ is subjective.

For some, good game AI is unobtrusive, staying out of the way and leaving the gameplay up to the player. For others, it’s a dedicated part of the action, just as active as the player is. What people want from games is individual, but there are a few features that make certain AI shine above the rest.

AI Behaviors and Agency Make NPCs Feel Valuable

One of the biggest failures of AI is a lack of behaviors. NPCs that don’t have any actions beyond standing around and waiting for you to continue don’t feel realistic or fun to play with. Characters that constantly need your help can be even more annoying; you spend your time trying to get them out of whatever predicament they end up in, which ends up feeling like an obligation rather than anything like entertainment.

Nate and Sam Uncharted 4 Game AI
Sam’s AI and dialog make him an interesting companion, despite his tendency to get into trouble. Image Source: Naughty Dog.

So how do developers combat that? They give their characters agency, or at least some semblance of it. While it won’t be fun if NPCs start solving your puzzles for you or stealing your kills, an NPC that feels like a valuable teammate is far better to play with than someone who just stands around or who constantly demands that you save them from a pack of wolves.

Take Uncharted 4’s use of Nate and Sam, for example. These two characters work well together, their banter and familiarity making them a delight to watch and play. But even better, Sam is a valuable companion—he tells you where enemies are, even marking or dispatching them for you, as well as suggesting how to solve puzzles and other obstacles. When he’s not helping, he’s wandering around and inspecting the scenery. It’s all programmed behavior, of course, but it makes him feel more believable, like an actual companion rather than a lackluster sidekick with nothing valuable to offer. It’s those little animations and helpful tips that make Sam a useful companion; even if it’s all preprogrammed, Uncharted’s scripted AI changes the way that we perceive him as a character.

Invulnerability Takes Companions From Liabilities to Useful Friends

Escort quests are a dreaded feature in video games. Some titles do them well, but others require players to protect squishy NPCs with no sense of self-preservation. They wander into danger, walk at a strange pace somewhere between the player’s walk and run speed, and die too easily, causing frustration.

Elizabeth BioShock: Infinite
BioShock: Infinite‘s Elizabeth can hold her own, in part because she’s invulnerable. Image Source: Major Nelson via Flickr.

While making an NPC invulnerable loses some of the thrill of protecting them, it does mean that you’re able to explore alternate methods of interaction. This is part of what makes BioShock: Infinite so appealing, despite the fact that it plays much like an extended escort quest.

Elizabeth, the heroine you’re tasked with escorting, is quite capable of handling herself. She’s invulnerable to enemy fire, so any weird AI decision she makes—such as running directly through a line of fire for no apparent reason—won’t actually cause her any harm. She’s more likely to hide behind cover and provide you with much-needed ammo or health if you’re low, as well as opening tears for additional battle leverage.

In short, she’s useful; unlike many escort characters, Elizabeth is a real teammate. She never feels like an obligation because she can’t die, and while that removes some of the tension from the battle scenes, her personality is big enough to hold both your interest and concern for her throughout the game. If you lose her, you’re losing an interesting character who quite often helps you out of a tight spot. The combination of story, invulnerability, and solid AI means that, while Elizabeth may not need your protection, you want to help her anyway; she’s useful and likable, and her programming makes her a friend, not a liability.

Flexible Controls Give Players the Power to Choose

The downside of any AI, even the most sophisticated kind, is that it’s never going to know precisely what you want it to do. No matter how adept it is at understanding commands, if you want a job done right, you have to do it yourself. That’s why games that let you swap characters are such a blessing—the AI will mind itself as long as you need it to, but you don’t have to rely on it to solve puzzles on its own if you can jump in and take the wheel.

mythological creatures in video games: Troll and I
Troll and Otto’s combined brains, brawn, and agility are all necessary to survive the threats surrounding them.

That’s how the upcoming Troll and I works. While both Otto and Troll operate independently if left alone, you’re able to swap characters at any time to make use of each character’s unique skills. Otto is quick and agile, while Troll’s bulk and brute strength make him valuable in different situations. You need both to make it through the game’s numerous trials, including surviving the Scandinavian wilderness.

When you’re not controlling a character, AI picks up the slack. They’ll fight at your side, but, if you need something more specific, you can swap into the other role instead. Sometimes a challenge will require more finesse than AI is capable of, but, rather than having to hope they’ll figure it out and not become a liability, you can take care of it instead. It’s a unique kind of teamwork that increases your ability to connect with each character because you can control and understand them, not because either one is dependent on you for success.

AI Should Be Smart, But Not Too Smart

AI is complicated. Players want their companions to feel real and helpful, but if they’re too helpful they can make a game overly easy. It’s a delicate balancing act, but changing a few key features, as these games do, is part of making game AI fun rather than frustrating. Playing games with others is great, but we want those “others” to be just skilled enough to be worthwhile—not so skilled that they overshadow us. That’s why these models work—we get to be the hero, our trusty sidekicks a perfect complementary match for our skills.

Troll and I lets you take control of two unique characters: big, powerful Troll and Otto, a teenage boy whose speed and finesse make him a formidable foe. Preorder your copy today!