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A murder mystery game 🕵️

· 21 min read

I created a murder mystery game using OpenAI.

Starting the game we get this plot generated

Welcome Sarah, you are the detective to this mystery.

The Characters

  • Harold Finley is a Private Detective. Analytical, diligent, slightly obsessive. Has a sharp eye for detail and a dry sense of humor.
  • Melinda Quill is a Librarian. Quiet, curious, and intelligent. Possesses a love for books, riddles and puzzles.
  • Dorian Walker is a Mystery Novelist. Eccentric, imaginative, and spontaneous. Often lost in thought and filled with wild theories.
  • Serena Johnson is a Forensic Scientist. Methodical, logical and introverted. She has a fascination for the eerie and macabre.

The Victim: Serena Johnson


🕵️ What do you want to do next? : go and chat with the librarian

I walk over to the library, where I find Melinda Quill busy reorganizing her shelf of books. As I approach her, she looks up from her work and gives me a small, polite smile.

"Good morning, Miss Quill," I begin, "I'm sorry to disturb you at work, but it's about Serena Johnson's case. Maybe you could spare a few minutes?"

Melinda nods, her eyes filled with concern. "Of course, Detective. How can I assist you?"

"I'd like to ask you some questions about Serena," I say. "Were you two close?"

"We knew each other through work," Melinda responds. "She often came here to read or borrow books. But we weren't particularly close. Is there something specific you want to ask about Serena?"

"I'd be interested to know if she had any habits, peculiarities or anything around those lines that could help me understand Serena better," I reply, Y "Did she frequent to a particular section of the library here?"

Melinda thinks for a moment, then says, "She mostly read forensic science and crime investigation books. Sometimes she would delve into horror or murder mysteries. On occasion, she borrowed true-crime books as well."

"Intriguing," I reply, "Also, can you remember any specific event, conversation, or anything unusual surrounding Serena's recent visits to the library?"

"I'm not sure if it's unusual, but I do remember her looking rather unwell some days. Like something was bothering her," Melinda adds, "She seemed particularly enthralled with a section dedicated to famous unsolved murder cases. She'd spend hours reading, sometimes even forgetting to return books."

"Interesting," I reply, making mental notes. "This will certainly help our investigation. Thank you for your willingness to help, Miss Quill."

🕵️ What do you want to do next? : Did you kill her?

Melinda looks shocked by my sudden and direct question. 

"No, Detective!" she exclaims, clearly taken aback. "I may love mysteries and riddles, but I would never harm a fellow human being! I am as taken aback by Serena's murder as anyone and am fully cooperative in your investigation", she reassuringly states.

🕵️ What do you want to do next? : Who do you think did kill her?

Melinda paused before answering, as if she was carefully considering her reply.

"That's your job to figure out, isn't it, Detective?" she said with a small smile. "As a librarian, I deal in facts, not speculation. I'm afraid that isn't particularly helpful for you."

"So you don't have any idea who could have wanted to harm Serena?" I ask, trying a different approach.

"I really don't," she responded, a sincere look in her eyes. "She was such a quiet, thoughtful individual. It's really hard to imagine who could do such a thing to her.."

"I appreciate your insight, Miss Quill. And if you happen to think of anything that might be useful for my investigation, please don't hesitate to let me know," I say, ending the conversation on a hopeful note.

🕵️ What do you want to do next? : visit Dorian at home to ask him a few questions

I make my way to Dorian Walker's residence. As a renowned novelist, his home is somewhat of a mansion, filled with writings, books, and antiques. He greets me at his door. 

"Ah, Detective Sarah, I was wondering when you would come around. Interested in a mystery writer's views on a real-life murder?" Dorian's face is a mix of intrigue and amusement.

"Exactly, Mr. Walker." I take a seat, "I wanted to ask you something about Serena Johnson."

"Ah, Serena," his face grave now. "What about her?"

"Did you two know each other closely?" I ask, my eyes scanning his expressions for anything peculiar.

"I'd say we knew each other," Dorian admits. "She had an interest in crime cases as one does in our field. We exchanged theories about notorious unsolved ones from time to time."

"I see," I reply. "Did she share anything unusual or out of order with you recently?"

"Not that I can remember," he replies a tad too quickly, before adding, "She was usually so meticulous, always carrying her research to a T, we just narrated our theories to one another."

"I see," I reply. "Are you aware that she was feeling unwell or disturbed about something recently?"

"I can't say I had noticed," he says, shaking his head. "To me, Serena was always passionate about her work, driven. I can't recall her mentioning anything about feeling unwell or troubled."

"You certainly provided a bit of insight, Mr. Walker," I say, as I rose from my seat. "But there is a chance I might return with more questions. In the meantime, should you remember something that might help, do inform me."

"Certainly, Detective," Dorian replies, his eyes twinkling with a spark of curiosity, "and good luck, mystery in real life is not as glamorous as in books, I assure you."

It was clear Dorian was hiding something, but I needed more evidence to prove it. As I exit his residence, I decide that another visit here might be beneficial.

🕵️ What do you want to do next? : Did you kill Serena?

Dorian's face is veiled with a mild shock at the straightforwardness of the question, masking any initial reaction he might have had. 

"Detective, do you ask each and everyone you meet if they are a murderer?" he responds with a laugh, attempting to brush off the accusation, but I notice a tightness around his eyes. "I understand where this is coming from, but I assure you, I am not responsible for Serena's untimely demise. I only know murder in the realms of fiction, not reality."

"I'm just doing my job, Mr Walker," I reply. "Everyone's a suspect until proven innocent."

"Then everyone must answer the same questions, mustn't they?" he chuckles and waves me off.

His nonchalance begins to raise my suspicion. Even if false, his display of calm could be an act.

"Just don't leave town," I respond while leaving. "I might have more questions for you soon."

"Just like in the novels," he smirks in response.

It's hard to tell if Dorian's sense of humor is off or if he's just a really good liar. Either way, I know I'm not done with him yet.

🕵️ What do you want to do next? : Ask Dorian who he thinks killed Serena

"Who do you think could have possibly wanted to harm Serena, Mr. Walker?" I asked, observing his reactions closely.

"Well, Detective, you know as well as I do that human motivation can be as complex as it is unpredictable," Dorian said, leaning back in his chair contemplatively. "Passions run strong, particularly in this field. Jealousy? Revenge? Perhaps a derailed investigation or a secret uncovered?"

He paused before adding, "As a mystery writer, I see all possible angles, but it's your job to pinpoint the right one. I can't guess who could have killed Serena. I only knew her through her work."

His cryptic response and evasion of my question hint at something else. I'd have to dig deeper into his connection with Serena and what he's hiding - one wrong move and the murderer could be right out of my reach.

🕵️ What do you want to do next? : go visit Harold. Ask how he knew her, if he killed her, and who he think might have killed her

I make my way to Harold Finley's office. A neatly stacked pile of case files, a magnifying glass to the side, and a black-and-white photo of what seemed to be his graduation from the academy marked his desk. 

"Detective Sarah," he greets as I walk in. "To what do I owe this pleasure?"

"Harold," I start, deciding to be straight to the point. "I'm here to discuss your relationship with Serena Johnson."

The mention of her name stiffens him a bit, but he quickly regains his composure. "When you're in the business of investigations, you cross paths. I knew Serena through work, respected her commitment and methodical approach. Obviously, we were from different branches- she was in forensics while I, well, you know my work," he chuckles dryly.

Sensing the gravity in the air, I press on with my most critical query, "Harold, did you kill Serena?"

Harold raises his eyebrows, clearly surprised by the sudden accusation, but his response is calm and firm. "No, Detective. I did not kill Serena."

"And who do you think could’ve done it?" I ask, trying to gauge his response closely.

"That is the one million dollar question, isn't it?" he returns with a wry smile. "We both know this line of work breeds enemies. Could be a case gone wrong, someone holding a grudge... or maybe a love gone sour. Serena was well-liked, but she was also uncompromising in her work. Could have rubbed someone the wrong way."

Harold's potential suspect ideas weren't a surprise to me, it was a trend in this case. The ambiguity of his responses did give me a prompt, though, to look closer at Serena's work life.

🕵️ What do you want to do next? : find out about Serena's work life

I decide to visit Serena's forensic lab, hoping to find some clues regarding her workplace behavior that might shed some light on her murderer. The place is a sprawling array of microscopes, charts, and biohazard bins. Her colleagues are somber, aware of the reason behind my visit.

I approach one of her close work associates, Dr. Marcus Gunther, a composed older man who had been working with Serena for years.

"Detective Sarah," Dr. Gunther nods, giving me his full attention. "How may I assist your investigation?"

"Thank you, Dr. Gunther. I'd like to understand Serena better, her interactions, behavior, everything about her workplace here. Anything you think could have factored into her murder."

"Serena was deeply passionate about her work," he begins. "She was almost obsessive with detail, methodical with her procedures. Always the first to arrive and the last to leave. Her work was her life."

"Did she have any problems with her colleagues? Or did she ever mention anything unusual lately?" I ask him, trying to dig deeper.

“Not that I'm aware of," He says after contemplating for a few seconds. "She was well respected here, her work was impeccable. And as far as I can recall, there wasn't anything unusual. Not in our conversations at least."

"Thank you, Dr. Gunther," I say, a bit disappointed at the dead end. "If you think of anything that could possibly assist with the case, please reach out immediately."

"Of course, detective," He nods, sympathetic.

As I leave the lab, I realize this case won't be as straightforward as I'd hoped. Serena's life, both personal and professional, seemed devoid of any visible reason for murder. There's something I'm missing, and I sense I have to dig deeper. Much deeper.

🕵️ What do you want to do next? : how did she die

The preliminary autopsy report confirmed that Serena Johnson's cause of death was due to a lethal dose of potassium cyanide poisoning. It was found in her system and it is believed to have been mixed in with her drink. The time of death was estimated to be approximately 8-10 hours preceding the discovery of her body. There were no signs of a struggle reported so it is likely that she didn't perceive any threat. It suggests a certain level of familiarity and trust with her murderer, someone she didn't think would want to harm her. The murder method - poison - doesn't have a specific MO associated with it, but it does hint at a calculated mind and careful planning, somebody who knew exactly what they were doing.

🕵️ What do you want to do next? : get all the suspects together, and have them all accuse one another

I arrange a meeting at the local police station, ensuring Harold, Melinda, and Dorian all arrive at the same time. As we gather in a room, a tension hangs like a thick blanket.

"Thank you all for coming," I start, my voice echoing in the silence. "I'm sure you're aware of why we're here. Serena Johnson's murder is an unsettling event, and each of you had familiar relations with her."

"What's with this arrangement, Detective?" Dorian interjects, his curious eyes darting between Harold and Melinda.

"Accusation. From each of you. Who do you believe killed Serena?" I plainly ask, my gaze steady on each of their faces.

Dorian chuckles, "Is this the part where I say 'I couldn't have done it, I was too busy writing my next murder mystery'?"

Before I could respond, he turns to Harold and Melinda, "Well, we know Harold here could pull off such a thing, considering his investigative experience. And Melinda, we can't underestimate the quiet ones, can we?"

As Dorian laughs at his own supposed joke, Melinda frowns slightly, a glint of worry in her eyes, "That's a rather cruel joke, Mr. Walker. I could assume the same of you with your knowledge of fictional killings." She then shifts her gaze to Harold, "And Mr. Finley, your line of work could justify your capability, but I choose to believe neither of you did it."

Harold reclines, fixing his gaze now on Dorian. "For all we know, Walker, you could be researching your 'next big hit' a little too intensely," he coldly suggests. Then to Melinda, "Quiet waters run deep, Quill. But I'm a detective, not an accuser without evidence."

A few accusations, a lot of defensiveness and an undercurrent of nerves; these responses tell me less about who might have done it and more about their fears and insecurities. From this point on, it's a game of psychology, of catching microscopic hints and tiny tells. The real murderer is somewhere in these denials and suspicions. And slowly, I'm starting to see the weapon, the motive, and the identity of the killer forming a gruesome picture - but I need hard, cold evidence.
Your accusation is incorrect. The investigation must continue!

🕵️ What do you want to do next? : ask each person where they were at the time of her murder

"Let's establish alibis," I say, my eyes scanning the three suspects. "Where were each of you at the time Serena was murdered? Let's start with you, Mr. Walker."

Dorian, leaning back in his chair, says casually, "I was at home, outlining a plot for my new book. My housekeeper can vouch for me."

Next, I turn my gaze to Melinda, "And you, Miss Quill?"

"I was at the library," she replies quickly, a slight tremor in her voice. "It was a busy day. Several people saw me there."

"And lastly, Mr. Finley, where were you at that time?"

"I had a late-night stakeout that day," Harold answers tersely. "One of my clients could confirm it."

It's an odd situation. Each of them has an alibi, but who is telling the truth and who is not? As they look at me, waiting for my next move, I find myself running through the facts I've gathered. There is a piece of the puzzle missing, and I need to find it. It draws me back to the victim herself, Serena Johnson. The answers must lie with her.

🕵️ What do you want to do next? : summarise the facts

I begin to piece together the data I've gathered so far.

The victim, Serena Johnson, was a highly respected forensic scientist. She was found dead in her home, killed by a lethal dose of potassium cyanide presumably slipped into her drink. The method of murder points to someone calculated and familiar with chemical substances. There were no visible signs of a struggle, suggesting she likely knew her killer and did not see the attack coming.

Among our suspects:

- Dorian Walker, a mystery novelist: Serena and he shared an interest in true crime and often swapped theories about unsolved cases. On the night of the murder, he claims he was home, working on a new novel.

- Melinda Quill, a librarian: Serena was a frequent visitor to the library, often reading books on crime investigation, horror, and famously unsolved murder cases. Melinda was in the library on the day of the murder.

- Harold Finley, a private detective: He had professional encounters with Serena, respecting her work and dedication. He was on a stakeout during the time of Serena's murder.

Each suspect provided an alibi that aligns with their respective professions. All suspects had a connection to Serena through her interest in crime, investigation, and mystery. The suspects accused each other during the meeting, but none provided a convincing argument.

The facts suggest that the murderer was someone who knew Serena well, was familiar with her routines and interests, and used these to commit the perfect crime. The evidence also points to someone intelligent and capable of handling dangerous substances - a trait common to at least two of our suspects.

🕵️ What do you want to do next? : go and speak to Harold's client about his alibi, and to Dorian's housekeeper about his alibi

For my first stop, I visit Harold's client, a middle-aged woman named Michelle Rodriguez, who hired Harold for a private investigation tied to her husband's infidelity case.

When asked about Harold's whereabouts on the night of Serena's death, Michelle confirms his claim, "Yes, he was on stakeout that night. I remember because I got a call from him with updates. It was quite late in the evening."

Feeling slightly relieved at Harold's proved alibi, I head over to Dorian's residence, where I meet his housekeeper, Maria.

"Good afternoon, Maria," I begin, "You work for Mr. Walker, correct?"

"Yes, Detective," Maria replies, instantly cautious at hearing my title.

"I was told by Mr. Walker that he was home on the night of Serena Johnson's murder, working on his next book. Can you confirm that?"

Maria looks thoughtful before responding, "Well, Detective, Mr. Walker does usually stay home and works on his writing... but, I don't remember if it was the same for that particular evening. After my work hours, I can't be certain of his whereabouts."

Even though Dorian's alibi isn’t as concrete as I'd hoped, it's a lead worth following up. Now more than ever, Serena's murderer appears to hide behind the pages of Dorian's fictional murder mystery. But until I can secure absolute evidence, all three suspects are part of this deadly puzzle.

🕵️ What do you want to do next? : search Dorian's house for poison

With a warrant to search Dorian Walker's house, I arrive at his splendid mansion, notifying him of our intentions. He leads me inside his home, looking somewhat perturbed but cooperating nonetheless.

As we begin our search, I am astounded by the volume of books, articles, and journals lining bookshelves throughout his home. The books range in topics from crime stories to forensic pathology. His study, where he claimed to have been on the night of the murder, is a sea of papers, books, half-consumed cups of tea, and antique collectibles.

We comb through the entire house methodically. Nothing out of the ordinary in the kitchen or his personal quarters. Then we reach his study. With the help of two uniformed officers, I carefully go through his work area, checking every drawer, file, notebook, and even the books he has recently been reading.

Hidden in one of the drawers of his study desk, we find a small box containing vials of various chemical substances, including potassium cyanide. The discovery sends a chill up my spine.

"This... this is for my research," Dorian stammers, looking at the box in shock. "I did not use it to poison anyone!"

Finding the poison is a significant breakthrough, but we still need direct evidence connecting Dorian to Serena's murder. This dark twist in the tale has caught the storyteller himself in a web of his own making. Until there's irrefutable proof, the fog on this case remains.

🕵️ What do you want to do next? : find irrefutable proof that he killed her and arrest him

Armed with the potential murder weapon found in Dorian's possession, I decide to take one more crucial step - comparing the substance found at Serena's house to the potassium cyanide found in Dorian's study. 

At the lab, using the residue from the glass found near Serena's body, the forensic expert confirms that the potassium cyanide in Serena's system is chemically identical to the cyanide found in Dorian's study.

"That's not my doing, Detective," Dorian pleads upon my return to his home. "Anyone could have accessed my home - my study!"

I regard him with a steady gaze, "You claim to be a mystery writer, Mr. Walker. But the mystery ends here."

With solid evidence, I formally charge Dorian: "Dorian Walker, you are under arrest for the murder of Serena Johnson. You have the right to remain silent. Anything you say can and will be used against you in a court of law."

As he's led away, a look of defeat replaces the mask of innocence on his face. I head back to the station, the weight of the case slowly being lifted off my shoulders. Justice has been served.

🕵️ What do you want to do next? : accuse Dorian

"We found potassium cyanide in your study, Mr. Walker," I say, my gaze unblinking. "The same poison that was used to kill Serena Johnson. The same chemical traced back to a glass found near Serena's body and now found in your possession. And your housekeeper couldn’t confirm your alibi for the night of Serena’s murder.”

Dorian tries to mask the alarm in his eyes, but his facade is cracking. "Detective, I—"

I interrupt him sharply. "You used your knowledge of crime to plan a perfect murder. But you overlooked one thing - there’s no such thing as a perfect crime."

"Under the charge of murder," I continue, "I am placing you under arrest, Dorian Walker, for the death of Serena Johnson."

🕵️ What do you want to do next? : accuse Dorian Walker

I take a thorough look at Dorian before I begin, letting the silence stretch between us for just a second too long.

"Dorian Walker," I finally say, my voice steady yet firm. "Evidence found at the crime scene and in your study confirms that the potassium cyanide that killed Serena Johnson and the sample found in your possession are chemically identical."

Dorian looks taken aback, his confident demeanor faltering slightly, "That... That can't be right. I've never..."

"Let me finish, Mr. Walker," I interject. "Serena was found dead in her apartment, with no sign of forced entry. Whoever killed her was someone she trusted, someone she would let into her home without fear. Someone like you."

His face pales ever so slightly, knowing he can no longer talk his way out of this.

"I used to enjoy a good mystery, Mr. Walker," I say, sighing. "But nothing beats the satisfaction of solving one. Dorian Walker, you are under arrest for the murder of Serena Johnson. You have the right to remain silent. Anything you say can and will be used against you in a court of law."

As he's led away, I can't help but feel a sense of justice. Serena may no longer be with us, but at least her murderer will pay for what he did.


The story generation is exceptionally good. And that it keeps the context of what was said in the interactions as well as what was mentioned in the story previously.

As far as gameplay, it needs a better intro. And it needs a clearer way as to how the game will end.

This level of text generation costs me about $3 a game. So if 10 people played 10 games a day, that would give me a bill of $300 a day. I could use a simpler (and cheaper) model, but risk creating stories that don't make sense. How much would someone pay to play a game like this?