Deduction Mechanics in Games

A few years ago, I became curious about whether it's possible to write code that generates logical-deduction puzzles.

It turns out, you can -- and you can also write code that solves them.

I wrote about the experience here, using the "Cheryl's Birthday" brain teaser as inspiration to create a murder mystery:

https://github.com/shaungallagher/cheryls-murder/blob/master...

The code is a bit convoluted -- it was hastily written during a Hack Days event -- but it's fun to see the end result!

>> I’ve been thinking recently about detective games, and in particular, the “deduction mechanic” — the gameplay system of linking “facts” together to produce a new and interesting conclusions that forward the story.

Pedant's corner: deriving new facts from known facts is logical abduction, not decudtion.

The way that Sherlock reasons is abductive reasoning, although he calls it deduction:

https://en.wikipedia.org/wiki/Abductive_reasoning#A_Theory_o...

I guess the term never really caught on in the popular language.

Are there any good detective games based around interrogating a suspect where you're given a decent amount of freedom in what you can say/ask over fixed dialogue trees?

Her Story can be viewed as something like this in a limited form, where there's a satisfying enough reason for the limitations.

Return of the Obra Dinn was awesome. Like Her Story, the deduction goes on in your own head or on paper in contrast to e.g. an unnatural UI that shows a nodes/lines diagram of facts where you're joining facts together to prove you know what's going on.

I've been writing a simple 2d arcade rpg a few years ago. I created a simple graph language for creating quests and started to design the system for specifying arbitrary quest conditions.

It started from simple things like "has player killed a monster of type X", "does player have item Y in inventory", "was the actor X in place Y already", "have player talked to actor Z about Q".

But then I thought it would be cool to add metainformation. "Have actor X seen player killing the monster Y". "Have any actor seen player talking about Q". "is there a chain of actors meeting each other from the actor that seen player killing actor X to the quest giver".

I tried to implement this naively and it turns out the amount of information is astounding. To the point that I'm still amazed our brains can do this.

I think you need the "Aha" moments to let you complete some task, or lead you to some place, or interact with some thing, whilst still hiding enough information to keep you curious. That way the moments of deduction are exciting because it lets you progress the story, and gets you closer to the final deduction.

For games with a grander theme like a whodunit, I think it's totally reasonable to have that just be revealed at the end, and if you got it right you can pat yourself on the back. Books and movies are no different, sometimes you figure it out before the book tells you what it was and you get to have a cheeky grin on your face when it turns out you were right, but that's all. If you really must gamify it, you could have your character accuse people, and if they get it wrong the cutscene shows who did it getting away or what have you.

I feel The Occupation meets the authors requirements. You play the role of a journalist trying to figure out what happened in a bureaucratic scandal, wandering through beautifully atmospheric old institutional buildings collecting documents and clues. There is a lot of freeform deduction and you will definitely not get everything on the first playthrough as some things you won't even realize you were looking for, unless you made those freeform deductions and knew to look for those clues or documents.

They do a great job of gamifying knowledge through meetings and interviews you have with different characters, and if you don't have the right bits of information then you simply don't have those questions to ask, and can't pick the right answers, and you get less information back out of the person.

This reads more like a wish list rather than analyzing how different games do it in different ways, which the title made me expect.

Wow this is like how in Genshin Impact, a character tells you to go find an item that you already have and when you talk to him again 5 seconds later, he says "woooow you found it after so long! you must have travelled far!".

My far most pleasurable experience is with the Ace Attorney series of games, which I think achieves it by the courtroom simulation.

Probably the best (and only one) I've encountered is the Painscreek Killings - a little known gem that I've been pestering my friends to try out. The only system it uses is the old Unity style first-person "interact with item in environment to read note or pick up key" mechanic. However, the design is intricately laid out so that only by making a conclusion in your head, you know where next to go in the small, but sufficient open world town the game takes place in. I think more detective games would benefit by taking inspiration from that game.

I think the critique of Return of the Obra Dinn is flawed. The game only seeks two pieces of information for every crew member, but in actuality, you need to crack out a paper and pencil and start "investigating" to get this information without brute forcing the game's mechanics. By asking less of the player it actually provides very rich deductive experience, unlike any other detective game I've experienced.

RPG games are terrible, invalid engineering. Insufferable garbage. They are about as fun as watching ads on 90s television, which is admittedly possibly better than staring at a brick wall. You will never have an RPG where it feels like you're playing the "Role", because what you are really doing is trying to walk in the right spot to trigger a switch. You will always see one way to "solve" a "problem" in any given situation that was just story-told to you, but the author preconceived a finite set of solutions (i.e., one) for you that can only be expressed by stepping in a certain coordinate bound. And this is just the tip of the iceberg concerning a real RPG. Most add all kinds of useless crap on top of this: like leveling systems, grinding, and purchasing things to make your weapon better (not even talking about microtransactions. I mean getting 100 gold to get item x to get item y to get a weapon you need to get to the next area). If a game needs to be so cluttered with emulating an open world with all kinds of details (in practice, these will all be thinly-veield consumeristic nonsense like getting a flower to use to craft or trade), it better be an Epic, and took multiple decades to create, not every single game a studio churns out every year. If it is not worth your time to build an actual interesting open world with an actual meaning (aside from consume product) behind the entities in said world, it's not worth my time to explore it; i will skip through everything, installing hack to skip forced dialog, etc, like every other game.