Wow, do I love a good mystery. I’ve been a fan of mystery stories since early days reading Encyclopedia Brown stories and trying to solve them. As I got older I watched shows like Colombo, and then started to read Sherlock Holmes.
Mysteries have been a staple of fiction forever, and most people I find love a good mystery. And TTRPG’s aren’t much different, and I find that few things get your players more excited than to investigate and solve a mystery at the table. In fact there are many TTRPG systems that are really optimized around mysteries. Some of the big ones being Call of Cthulhu, Kids on Bikes, and even the latest release Candela Obscura.
Now there are some out there who would tell you that Dungeons and Dragons is not built for mysteries, and to be honest I reject that. Any RPG system can support a mystery and it’s been my experience that some of my players best sessions that are most memorable involve them solving a mystery.
But the biggest question is, how do you build a mystery and make it something your players will enjoy.
For the sake of this explanation I’m going to steal from a fantastic mystery movie, “The Glass Onion.”
Core of the Onion – Know the answer to your mystery…
Ok, so the first thing sounds somewhat obvious, and it’s that you need to know the answer. But let me get more specific about this. For you to be able to support a mystery, you need to know exactly what went down at the crime scene. For the sake of this discussion let’s use a murder investigation, where a local noble has been murdered.
The very first thing you should do is answer three questions:
- Who is the victim?
- Who is behind the murder? And who committed the crime? Notes these might be different if it was a “contract killing.”
- Why did this murder happen?
These three pieces of information will give you the basis to build out the rest of the investigation and improvise when you need to. This is the core of any mystery you build. And most people start with the “how” but that’s not nearly as important.
Once you have the above, you are ready to look at the next level of the mystery.
Layer 2 – Where did it happen?
The next part of this mystery is to figure out where it happened. And this is more than just saying “It happened at their manor.” The important thing here is to think of the details of the location where the murder happened. For example things like:
- Why did it happen here?
- What does they room it happened in look like normally?
- What was the victim doing when it happened?
- What protections were in place that had to be bypassed?
Knowing what the default status quo is will help you fill in the clues for the players to find.
Layer 3 – Figure out “how it went down.”
The next part of the mystery is the “how”, and specifically how the murder it happened. And this is where you have to figure out how the murder happened. Did they force their way in? Was the victim surprised? How did they get passed guards of defensive? These are critical questions to answer.
Now while you are figuring this out, you need to make note of the things that happened and the effect on the location and the environment. Given the status quo you identified above, you should be able to identify what happened to make the environment be out of place.
As part of this consider things like, “Did the victim fight back?” Like if the victim is a wizard maybe he used spells to defend himself. This will give you the first set of clues for your players to follow.
Layer 4 – What mistakes did the murderer make?
Now the next layer of the onion for this mystery is the most critical part, “What mistakes did the killer make?” This is the part that most people I find overlook. This represents the most important clues to help send the players on the the path to helping solve the mystery. All killers make mistakes in covering up their crimes and if you look at any true crime show they will tell you these mistakes are the key to catching them.
Layer 5 – Figure out alternatives
Now the next layer of the mystery is to build out potential alternatives. Who are the other potential suspects, and why are they potential options? I recommend following the rule of 3 with suspects, because the human mind gravitates towards it. So there should be the perpetrator and two other potential suspects, and some of the clues should point to them as well.
Layer 6 – Make sure there are resources that the players can call on.
Now this is the trickiest option, but you want to make sure the players are able to take advantage of specific resources they uniquely have. If they have a contact in the Watch Brigade, they should be able to call upon them. If they know someone who lives in the building, that person should have some form of a information.
The key part is you want the players to feel like they got an edge on the investigation due to their past efforts.
Pitfalls to avoid
The most important thing to avoid, don’t ever create a situation where the critical path information the players need hinges on a single roll. This causes a scenario where the investigation can never finish.