Core Vs. Alternate Scenes

In response to our scenario design workshop, we were asked to delve a bit further into the distinction between core and alternate scenes in a GUMSHOE adventure.

TL;DR: Make sure there’s one path through a GUMSHOE scenario. Those are your core scenes. Add more paths. Those are your alternate scenes.

A Core Scene provides one or more core clues—information the characters need to find other scenes, where they will gain further information and ultimately gather all the facts they need to solve the central mystery.

To confirm that your story has such a path, plot your core scenes on a diagram. If you can draw a line connects them all, you have a story the characters can be successfully navigate.

For players to exercise agency, though, they must also be able to choose how they move through the story. That’s where the Alternate Scenes come in—they provide other ways for gain some or all of a scenario’s core clues.

You can build in player choice by using only Core Scenes, with scenes that include more than one core clue. If the scene “Library Fire” contains two core clues, which lead to “Coal Chute” and “Wary Widow,” the group that chooses “Coal Chute” first creates a different sequence of events than the one that picks “Wary Widow” first.

Alternate scenes allow a simpler, surefire way of guaranteeing choice within the story. If the core clue leading to “Coal Chute” is found both in “Library Fire” and “Map in the Glovebox,” the players can get to it from at least two directions.

You don’t need more than two or three alternate scenes. By definition, an alternate scene might not happen. By adding more of them you both increase choice, and increase the amount of material you prepare that won’t appear in play.

Not all alternate scenes include core clues. They might feature interesting or fun sidetracks that players can go down or not, as they prefer.

Other scenes might put the characters in danger without providing information. Most notable of these types is the Antagonist Reaction, triggered by player actions, in which bad guys initiate events that push back against the protagonists.

Non-informational scenes, triggered by player decisions, appear in some GUMSHOE games, an example being the Hazards seen in The Yellow King.

Every scenario diagram will and should look different. (The one shown here has its scene titles stripped out, to avoid spoilers.) As you can see, it is a pretty simple example, with a couple of Alternate Scenes and as many Hazards.

When designing a scenario, the first sequence of scenes you invent as you plot from beginning to end are your Core Scenes. That’s almost certainly the easiest and clearest course of investigation for the characters to follow.

When you build in additional choice by creating additional scenes that provide core clues, those are your alternate scenes.

The core / alternate distinction is a tool that helps the designer ensure that the scenario includes a) one viable path through the story and b) and other paths, too.

If you’re writing for another GM to run, the distinction shows your work, indicating which scenes will most likely happen and which ones might or might not.

Players never need to know any of this. For them, the scenes they choose to activate are the story. They don’t see what might have happened if they’d made other choices—unless they read the scenario, or get the GM to tell them.

Though the difference between the two scene types may seem complex when explained, it’s dead simple in practice:

  1. Find one sequence of scenes the characters can navigate to solve the mystery. Those are your Core Scenes.
  2. Add scenes that provide alternate paths through the scenario. Those are your Alternate Scenes.

As long as you follow those two simple steps, you can’t go wrong.


GUMSHOE is the groundbreaking investigative roleplaying system by Robin D. Laws that shifts the focus of play away from finding clues (or worse, not finding them), and toward interpreting clues, solving mysteries and moving the action forward. GUMSHOE powers many Pelgrane Press games, including The Yellow King Roleplaying Game, Trail of Cthulhu, Night’s Black Agents, Esoterrorists, Ashen Stars, and Mutant City Blues. Learn more about how to run GUMSHOE games, and download the GUMSHOE System Reference Document to make your own GUMSHOE products under the Creative Commons 3.0 Attribution Unported License.

One Response to “Core Vs. Alternate Scenes”

  1. This should be a 5 hour video discussion… it’s the primary cause for my inability to complete my campaign creation. I see the conspyramid and try to make things fit together, and it’s not always easy

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