The fiction at the intersection of mystery novels and social deduction games (like Werewolf or Blood on the Clocktower) prompted this idea for a mystery scenario in a TTRPG. This framework could work for any game where a mystery is central to the campaign premise; it is, like my last mystery pitch, otherwise setting- and system-agnostic. It simply needs various NPCs who are suspects in whatever the substance of the mystery is. We’ll use a murder as a classic example, but it could be adapted to any kind of mystery where the goal is to figure out who knows the truth or who is responsible for the central mystery.
The structure of the scenario is as follows:
- The PCs are trying to solve a murder. They are on the clock (literally or figuratively, as in clocks from Blades in the Dark).
- Various NPCs are suspected of the murder.
- One (or more) of those NPCs is actually guilty of the murder, and wants the mystery to remain unsolved, or to be solved incorrectly.
- The rest of the suspects genuinely want the mystery solved, either as a matter of principle, or because they cared about the victim, or merely so that they themselves will be exonerated.
- Each and every suspect has a key secret. This is something they want to conceal, possibly because it is illegal, immoral, embarrassing, or compromising. No key secret should be on the same scale of importance as the central mystery, i.e., no suspect is guilty of anything as bad as murder. A key secret should be something like an affair, a civil crime like embezzlement, a child born out of wedlock (in a culture that forbids it), sketchy foreign entanglements, or something similar. Serious issues that would influence the NPCs’ behavior, and will incentivize them to lie and deceive, but decidedly Not As Bad As Murder. This is a common trope in many mystery stories, where the detective interrogates someone who is suspicious or evasive. They eventually learn their key secret, but doing so only removes a red herring from play; it doesn't solve the central mystery.
- Each and every NPC suspect can be recruited to help solve the mystery by the PCs.
- Recruiting a suspect gets the PCs access to everything the NPC knows, except for their key secret. The NPC will still lie and dissemble to hide their key secret.
- Aside from their key secret, the NPC suspect will help as best they can to solve the mystery, offering any individual knowledge they have of the crime, as well as any skills or expertise they possess. However, their help comes at the cost of complications stemming from the key secret itself, or actions they take to hide it. Depending on the system, the “cost” can be a concrete game mechanic, like a GM intrusion, or something more implicit and abstract. Either way, the players should see the connection between the NPC and the resulting complication.
- However, if the PCs figure out the NPC’s key secret, this tension is resolved. From that point on, the PCs can take advantage of the NPC’s help without complications or costs.
- Remember that one of these NPCs is actually guilty of the murder. The murderer can be recruited just like any other NPC. Their key secret, of course, is that they’re the murderer.
- If the party recruits the murderer, the GM starts a hidden countdown clock (or speeds up an existing clock) as the murderer tries to undermine the PCs or complicate their instruction.
This hits on a lot of things I want from an RPG premise. Time pressure. Resources at a cost. Players rewarded for asking questions and figuring things out. Consequences that make sense to the PCs. Motivations that make the players say “ohh, of course” after the mystery is solved. Now I just need to find an occasion to run this scenario. The clock is ticking…
