SPOILER WARNING: This post discusses the stories of Mark of the Ninja and Persona 4. If you haven’t played them yet, you might want to stop here. They’re both great games that deserve to be experienced without knowing what’s coming.

In order to use every resource at their disposal, game designers first have to recognize all of the possibilities. Some are easy and obvious: computer memory, playing cards. Others are more esoteric: tablets as addendums to board games, for example. Finally, there are the little-used, usually-unnoticed, difficult to employ resources, the narrow ones that are exceptionally powerful in the right situation. As an example, let’s take a look at player assumptions about how video game stories work.

Most video games have some unrealistic aspects that we accept, expect, and do not even process as out of the ordinary. Invisible walls limit our progress, even though the world appears to extend further. We can’t cross low objects because there’s no jump button, even though in the real world a few books or papers on the floor would pose no barrier. Conversations are limited and short to the point of rudeness. After a while none of these inhibit suspension of disbelief; we grow accustomed to and ignore them.

Mark of the Ninja does something canny with the way we accommodate ourselves to technical limitations on video game stories. Rather than just going along with our expectations, it uses them as a resource to make the story better.

(The SPOILERS start right here!)

In the game players take the role of a ninja who has gained Real Ultimate Power–but the power comes at the cost of gnawing, growing insanity. Players are led through the ensuing adventure by a helpful fellow ninja who provides guidance, commentary, and focus.

The guide routinely appears from nowhere and then disappears off-screen, never to be caught up with no matter how quickly the player-ninja moves. Occasionally the guide even does the impossible, able to “find another way” when there’s only one route.

I suspect that most players write all of that off completely, just as I did. Sure the NPC guide can do unlikely things: NPCs often can. They’re narrators, not subject to the limitations of the reader/player. Having them enter and leave the screen at all is a kindness, a nod to verisimilitude.

The big twist comes at the end of the game, when we learn–

(Seriously, SPOILERS!)

–that the guide was never there at all! She’s a visual representation of a voice in the ninja’s head, created by the ninja’s own mind so that the voice would seem to be coming from somewhere. Far from being an anchor against insanity, she’s a symptom of it!

With that single reveal, the entire game is thrown into question. Up to that point the goal has been clear: first to stop an attack on the ninja’s clan, then to take revenge on the evil megacorporation that attacked the clan, and then to take revenge on the clan’s own leader when it becomes clear that his schemes prompted the attack in the first place. However, all of those goals were presented by the guide–who was never really there, who’s just an expression of the ninja’s insanity. The player has to reevaluate the evidence, based not on the suddenly-unreliable narrator but rather on the player’s own judgment.

At the end of the game the player has to decide whether to strike down the clan leader. It’s a gripping moment because of the way expectations have been turned on their head. Throughout the game the player had a confidence born of the simplicity of most video game storytelling: the NPC tells you what to do and the challenge is in doing it. Now the NPC safety net is gone, and the player feels all the more adrift because it was once there.

By playing with expectations Mark of the Ninja goes beyond telling players that their character is going insane. It makes the player feel confusion and distress, thereby moving some distance toward putting the player in the character’s shoes. Mark of the Ninja uses the player’s assumptions just like it uses art, voice acting, and sound effects: as a resource it can call on to promote immersion.

Persona 4 does something similar, although its implementation of the technique is arguably less impressive. At the end of Persona 4 its characters feel that they have solved a mystery: they’ve discovered the identity of a murderer, learned his motives, and stopped his crime spree. There’s even an end-of-game wrapup of the sort that closes video game stories.

However, attentive players will note that the facts don’t quite add up. Good detectives among them won’t be satisfied, and if they insist on continuing to play rather than letting the credits roll they’ll discover that the game isn’t over yet! The true ending, with its ultimate reveals and conclusive answers, lie a few hours of gameplay beyond.

Unfortunately, it’s not easy for good detectives to signal that they want to keep investigating. It requires an unintuitive command that isn’t even legal at any other point during the game, with the result that checking an FAQ is almost required. That steals a lot of drama from what’s supposed to be the player’s biggest test.

Nevertheless, Persona 4’s handling of the player’s expectations is interesting and worth studying. The game demands that players rise above genre conventions to look hard at the mystery and decide for themselves whether it’s been solved, rather than going along when the game signals that they’re done. In the process Persona 4 captures something of real-world detective work, which is rife with incentives to stop investigating and close the case. A single weakness in Persona 4’s implementation thus takes nothing away from the superb underlying idea of using the player’s own assumptions to make her participate more fully in the mystery.

Video games have developed, as a medium, certain conceits. Good games can rely on those conceits, using them to hide technical limitations. It’s possible to go further, however, using not just the conceits as a resource but the expectations they’ve given rise to as well. Mark of the Ninja and Persona 4 demonstrate that being conscious of player assumptions regarding “how game stories work” allows designers to play off of them, potentially to very powerful effect.