For the GUMSHOE system (used in The Esoterrorists and The Trail of Cthulhu), Robin D. Laws decided to get rid of the concept of needing to find clues. In each “scene” of an investigation scenario, there is a “clue”. It’s automatically assumed that the investigators will find this clue.

This removes three of our four chokepoints, leaving only the necessity of using the clue to make the correct deduction (i.e., the deduction which moves you onto the next “scene” where the next clue can be imparted). And, in the case of the GUMSHOE system, even this step can be tackled mechanically (with the players committing points from their character’s skills to receive increasingly accurate “deductions” from the GM).

This is a mechanical solution to the problem. But while it may result in a game session which superficially follows the structure of a mystery story, I think it fails because it doesn’t particularly feel as if you’re playing a mystery.

Laws’ fundamental mistake, I think, is in assuming that a mystery story is fundamentally about following a “bread crumb trail” of clues. Here’s a quote from a design essay on the subject:

I’d argue, first of all, that these fears are misplaced, and arise from a fundamental misperception. The trail of clues, or bread crumb plot, is not the story, and does not constitute a pre-scripted experience. What the PCs choose to do, and how they interact with each other as they solve the mystery, is the story. As mentioned in The Esoterrorist rules, we saw this at work during playtest, as all of the groups had very different experiences of the sample scenario, as each GM and player combo riffed in their own unique ways off the situations it suggested.

But, in point of fact, this type of simplistic “A leads to B leads to C leads to D” plotting is not typical of the mystery genre. For a relatively simplistic counter-example, let’s return to Sherlock Holmes in A Study in Scarlet:

WATSON: “That seems simple enough,” said I; but how about the other man’s height?”

HOLMES: “Why, the height of a man, in nine cases out of ten, can be told from the length of his stride. It is a simple calculation enough, though there is no use my boring you with figures. I had this fellow’s stride both on the clay outside and on the dust within. Then I had a way of checking my calculation. When a man writes on a wall, his instinct leads him to write above the level of his own eyes. Now that writing was just over six feet from the ground. It was child’s play.”

This is just one small deduction in a much larger mystery, but you’ll note that Holmes has in fact gathered several clues, studied them, and then distilled a conclusion out of them. And this is, in fact, the typical structure of the mystery genre: The detective slowly gathers a body of evidence until, finally, a conclusion emerges. In the words of Holmes himself, “When you have eliminated the impossible, whatever remains, however improbable, must be the truth.”

What is true, however, is that in many cases it is necessary for many smaller deductions to be made in order for all of the evidence required to solve the mystery to be gathered. However, as the example from A Study in Scarlet demonstrates, even these smaller deductions can be based on a body of evidence and not just one clue in isolation.

This observation leads us, inexorably, to the solution we’ve been looking for.

Continued tomorrow…

Mystery scenarios for roleplaying games have earned a reputation for turning into unmitigated disasters: The PCs will end up veering wildly off-course or failing to find a particular clue and the entire scenario will grind to a screeching halt or go careening off the nearest cliff. The players will become unsure of what they should be doing. The GM will feel as if they’ve done something wrong. And the whole evening will probably end in either boredom or frustration or both.

Here’s a typical example: When the PCs approached a murder scene they don’t search outside the house, so they never find the wolf tracks which transform into the tracks of a human. They fail the Search check to find the hidden love letters, so they never realize that both women were being courted by the same man. They find the broken crate reading DANNER’S MEATS, but rather than going back to check on the local butcher they spoke to earlier they decide to go stake out the nearest meat processing plant instead.

As a result of problems like these, many people reach an erroneous conclusion: Mystery scenarios in RPGs are a bad idea. In a typical murder mystery, for example, the protagonist is a brilliant detective. The players are probably not brilliant detectives. Therefore, mysteries are impossible.

Or, as someone else once put it to me: “The players are not Sherlock Holmes.”

Although the conclusion is incorrect, there’s an element of truth in this. For example, in A Study in Scarlet, Sherlock Holmes is investigating the scene of a murder. He discovers a small pile of ashes in the corner of the room. He studies them carefully and is able to conclude that the ashes have come from a Trichinopoly cigar.

Now, let’s analyze how this relatively minor example of Holmesian deduction would play out at the game table:

(1) The players would need to successfully search the room.

(2) They would need to care enough about the ashes to examine them.

(3) They would need to succeed at a skill check to identify them.

(4) They would need to use that knowledge to reach the correct conclusion.

That’s four potential points of failure: The PCs could fail to search the room (either because the players don’t think to do it or because their skill checks were poor). The PCs could fail to examine the ashes (because they don’t think them important). The PCs could fail the skill check to identify them. The PCs could fail to make the correct deduction.

If correctly understanding this clue is, in fact, essential to the adventure proceeding — if, for example, the PCs need to go to the nearest specialty cigar shop and start asking questions — then the clue serves as chokepoint: Either the PCs understand the clue or the PCs slam into a wall.

Chokepoints in adventure design are always a big problem and need to be avoided, but we can see that when it comes to a mystery scenario the problem is much worse: Each clue is not just one chokepoint, it’s actually multiple chokepoints.

So the solution here is simple: Remove the chokepoints.

Continued tomorrow…