Deductive Puzzles

Adventure games are filled with their fair share of sleuthing, so why do they often turn into a parody of MacGyver?

Well, gameplay, of course. Browsing the scenery for usable objects — whether they can be picked up or not, and whether they can be used by themselves or in conjunction with other objects — is the interactive cause-and-effect bit.

Way too many designers have asked themselves that very question.

Considering how many adventure games revolve around solving mysteries, though, it’s surprising that so few of them rely on the player’s deductive skills. Instead, the audience is often stuck doing all sorts of illogical things, especially on a micro level. There’s usually a clear goal, but getting there is a matter of figuring out the logistics, not the mystery.

Now relying on the player’s deductive skills can be a big challenge. It’s not the most casual concept, it can be difficult to keep all the details of the “big picture” in one’s head, and even small discrepancies between the player’s conclusions and the designer’s intentions can result in an impasse.

Still, it’s not impossible.

Despite the suspenseful music and the serious nature of the crimes, Phoenix Wright’s cross-examinations are actually a very casual mechanic.

The Ace Attorney series gets around many of these hurdles by staying extremely focused. Whenever a new case begins, you can be pretty sure that your client is innocent and that you possess — or will eventually attain — the tools to prove it. The protagonist’s internal monologues are also a constant source of clues, and various other characters periodically chime in with advice. Finally, you only have a limited number of inquiries to pursue, and choosing the right path usually boils down to picking the correct multiple-choice answer.

The games still contain traditional adventuring aspects such as examining crime scenes, but where the series really excels is the court room drama. These segments are based on questioning witnesses, thoroughly investigating evidence, and interacting with the judge and the prosecution. Since the games are very tongue-in-cheek, there’s no real preparation involved — the player is thrown into the fire and learns as he goes.

Of course the lack of prep-work and the continuous stream of new witnesses and evidence isn’t exactly realistic, but it works gameplay-wise. It speeds up the intro to the “good parts,” i.e., the court room scenes, and compartmentalizes the player’s tasks. Witnesses run on a loop, and, until the correct course of action is discovered, the game doesn’t progress. Distinct audible cues accompany the player’s choices, and once the proper selection is made, a new loop is initiated (often accompanied by new evidence). It’s an approach that doesn’t require the player to become immediately familiar with all the facets of the scenario, and it serves to ease him through the various segments that compose it.


Another adventure game that attempts to explicitly tie deductive work into its gameplay is Gabriel Knight 3: Blood of the Sacred, Blood of the Damned. The two main characters of GK3 have access to an in-game computer named SIDNEY that keeps track of suspects, fingerprints, memos, notes and maps. The computer can also analyze various files and documents for patterns and hidden symbols, translate languages, and plot geometric shapes onto images — two central mechanics of its renowned Le Serpent Rouge puzzle.

The versatile — if somewhat unfocused and intimidating — SIDNEY.

SIDNEY works well, but its functionality is a little scattered. The little computer acknowledges correct deductions, but these are fairly open-ended and rely on somewhat subjective interpretations of the designer’s script. Overall SIDNEY is still a good mechanism for gating the game, and it helps to alleviate the MacGyver syndrome.

One more interesting title to throw into the mix is Opera Omnia.

Opera Omnia, of cities and men.

It’s not an adventure game, but it relies on a single interface that’s meant to reflect the player’s deductions. The concept is simple: connect a series of dots to prove a given hypothesis about population fluctuations. The dots represent cities, and the connections are emigration routes. The diagrams these two elements compose reside on a timeline, and connections can be made or unmade anywhere along the timeline’s path.

Since the hypothesis is always stated before a level begins (or at least they were in the stages I played), the actual gameplay feels a bit like struggling with office software; you know what you want to do, you just have to figure out how to do it. The concept itself is sound, though, as the interactive diagrams limit the player’s choices while constantly providing feedback on his guesses. Once the selected connections match the indicated criteria, a report can be submitted. This provides a clear goal and prevents the player from making incorrect deductions.

Now, how can the lessons of the above three titles be utilized?

Well, let’s apply them to a typical premise of an adventure game: a homicide detective story with a unique interface, a multimedia bulletin board.

Something like this, except filled with blood samples, audio recordings, bits of surveillance data, etc.

The bulletin board is scrollable/zoomable and houses all the notes and evidence of a case. It’s a single view of all the vital information required to solve the mystery, and, more importantly, it’s the tool that represents the player’s deductions. Each piece on the board is manually pinned on and can be connected to any other pieces, with the board automatically refusing illogical connections, e.g., a firearm found at the murder scene cannot be linked to the body if a forensics report — which is already connected to the victim — indicates that the cause of death was exsanguination due to numerous lacerations.

Forcing the player to manually manipulate the board is empowering and creates a sensation of gradually building a case. Furthermore, a single big-picture view is easy to interact with, and it can also help the player visualize scenarios that he wouldn’t have otherwise considered.

Since cases naturally start off with just a couple of bulletin board items, the player is eased into the mystery. The board itself serves as a gating mechanism, requiring proper connections to be made in order to unlock new inquiries, e.g., once the mother’s alibi was proven to be a lie, a search and/or arrest warrant could be procured.

Much like Battleship, Clue was actually more about guessing than any deductive work.

The actual process of identifying the culprit(s) follows a Clue like approach, i.e., who, where and (with) what, with an additional when, why and how thrown in to complete the W5H approach. These six categories are associated with each suspect, and they fill up as evidence is amassed and properly connected to the case. An interesting side note to this is that not all the fields need to be completely filled in order to solve a crime. For example, if someone was videotaped committing a murder in a crowded mall, it might not be necessary to figure out their motive in order to prove them guilty. This could open up all sorts of possibilities for not only skipping certain parts of the mystery, but maybe even coming to an incorrect conclusion (it’s a risky concept, but could be really interesting for the story). Loose ends could also carry over from one case to another, and unexpected events such as a key witness being murdered — effectively nullifying his testimony — would add variety to the goals and the pacing of the game.

Finally, all the pieces on the board should be context sensitive and utilize a hint-dispensing system. This could come in the form of monologues from the player character, or advice from co-workers and other characters.

The bulletin board is a game-specific solution, but its tenets are portable and can be implemented in any number of ways. They’re also fairly easy to follow, and should make deductive work accessible for even the most casual gamers.


  • I’ve been playing around with an idea, and this goes toward supporting it.

    “Ideas are a dime-a-dozen, it’s being able to implement something that counts”. And so we have an industry full of chintzy ideas with over-wrought implementation. Turning the player’s intelligence into little more than futzy busywork? Well, you’ve solved that case. No real choice or consequence, just the illusion of them.

    “Forcing the player to manually manipulate the board is empowering and creates a sensation of gradually building a case.”

    Is that a fact? Or did you simply come up with that on your own and, thanks to a byzantine thought process largely based on the vagaries of whatever alternate reality developers inhabit, suddenly find it true? I’m guessing option B, since your solution cleverly tries to work out at outlet for the PLAYER’S deductive skills when the core issue is one of the developer making fucking sense to begin with.

  • Ideas being cheap is not a novel concept, and, despite your seeming distaste for developers, most would agree.

    However, I don’t quite understand your complaints. The above article was about deductive puzzles as an alternative to the MacGyver approach, not “intelligent” mysteries and non-linear gameplay (although I hinted at the latter by suggesting that the bulletin board wouldn’t require all the evidence in order to solve a case, and that incorrect conclusions could be reached).

    As for:

    “Forcing the player to manually manipulate the board is empowering and creates a sensation of gradually building a case.”

    Well, that was a statement. It’s based on the following:

    A). It’s empowering because it gives the player power where he had none before, i.e., it puts him in the driver’s seat where he figures out the mystery instead of relying on cutscenes filled with exposition.
    B). It creates a sensation of gradually building a case by requiring the player to do just that very thing. Many, many games — including the aforementioned Opera Omnia — are a good example of this.

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