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Template metadata

id: module_mystery title: Mystery Module type: module_mystery level: module purpose: Investigation-focused adventure with clue trails, suspects, and revelations author: Mimir Team

Module-specific metadata

module_number: 1 theme: “[Theme]” tone: “Mystery” estimated_hours: 6

Catalog references (machine-readable)

monsters:

Mysteries often have fewer combat encounters

  • encounter: confrontation name: “[Culprit’s Muscle]” source: MM quantity: 2 notes: “Guards or henchmen”
  • encounter: final_showdown name: “[Culprit or Creature]” source: MM quantity: 1 notes: “The real threat”

npcs:

Mysteries are NPC-heavy - suspects, witnesses, victims

  • role: victim name: “[Victim Name]” source: campaign location: “[Crime Scene]” notes: “What happened to them”
  • role: suspect name: “[Suspect 1]” source: campaign location: “[Their Territory]” notes: “Motive: [Why they’d do it]”
  • role: suspect name: “[Suspect 2]” source: campaign location: “[Their Territory]” notes: “Motive: [Why they’d do it]”
  • role: suspect name: “[Suspect 3]” source: campaign location: “[Their Territory]” notes: “Motive: [Why they’d do it]”
  • role: culprit name: “[The Real Culprit]” source: campaign location: “[Their Territory]” notes: “Secret: [How they did it]”
  • role: informant name: “[Key Witness]” source: campaign location: “[Location]” notes: “Knows: [Crucial information]”

items:

  • location: crime_scene name: “[Evidence Item]” source: campaign quantity: 1 notes: “Key physical evidence”
  • location: reward name: “[Payment/Treasure]” source: DMG quantity: 1 notes: “For solving the case”

variables:

  • name: mystery_name type: string description: Name of the mystery default: “[Mystery Name]” required: true
  • name: module_number type: number description: Module number in campaign sequence default: 1 required: true

Module {{module_number}}: {{mystery_name}}

Investigation-focused adventure


1. Overview

Pitch: [One sentence describing the mystery]

Central Mystery: [What question must be answered?]

The Truth: [What actually happened - DM only]

Red Herring: [The believable false lead]

Estimated Play Time: [X hours]

The Hook

The Crime/Event: [What happened that draws players in]

Why Now: [Why this must be solved immediately]

Who Hired Them: [Who wants the truth and why]

Module Structure

[CRIME] → [INVESTIGATION] → [REVELATIONS] → [CONFRONTATION]
 (hook)    (suspects/clues)   (truth emerges)   (resolution)

2. The Crime/Event

What Happened: [The inciting incident]

When: [Timeline of events]

Where: [Location(s) involved]

Visible Evidence: [What’s immediately obvious]

Hidden Truth: [What’s actually going on]


3. Cast of Characters

The Victim(s)

AspectDetails
Name[Full name and title]
Role[Their place in community]
What Everyone Thinks[Common assumption about what happened]
The Real Story[What actually happened to them]

Suspects

Suspect 1: [Name]

AspectDetails
Public Face[How they present themselves]
Motive[Why they’d commit the crime]
Opportunity[Could they have done it?]
Alibi[Their story for the time in question]
Secret[What they’re actually hiding - may not be the crime]
Clues They Provide[What investigating them reveals]

Suspect 2: [Name]

AspectDetails
Public Face[How they present themselves]
Motive[Why they’d commit the crime]
Opportunity[Could they have done it?]
Alibi[Their story]
Secret[What they’re hiding]
Clues They Provide[What investigating them reveals]

Suspect 3: [Name]

AspectDetails
Public Face[How they present themselves]
Motive[Why they’d commit the crime]
Opportunity[Could they have done it?]
Alibi[Their story]
Secret[What they’re hiding]
Clues They Provide[What investigating them reveals]

The Real Culprit: [Name]

AspectDetails
Public Face[How they seem innocent]
True Motive[Why they really did it]
The Method[How they did it]
The Cover-Up[How they’re hiding their guilt]
Fatal Flaw[What will ultimately give them away]

4. Investigation Locations

Primary Crime Scene: [Location Name]

Obvious Clues:

  • [Clue]: [What it suggests]
  • [Clue]: [What it suggests]

Hidden Clues: (require searching/skills)

  • [Clue]: Investigation DC [X]
  • [Clue]: Perception DC [X]

Secondary Location: [Location Name]

Access: [How PCs learn about it]

What They Find: [Clues and information available]

Guardian/Obstacle: [Who/what makes it difficult]

Secret Location: [Location Name]

Discovery: [How it’s found - requires breakthrough]

Significance: [Why it matters to the case]

Danger: [What threatens PCs here]


5. Clue Structure (Three-Clue Rule)

Essential Clues

ConclusionSource ASource BSource C
[What PCs must realize][How to find it][Alternative source][Third source]
[What PCs must realize][How to find it][Alternative source][Third source]
[What PCs must realize][How to find it][Alternative source][Third source]

Clue Layers

Layer 1: Surface Clues

  • Physical evidence at the scene
  • Witness accounts (may be unreliable)
  • Initial assumptions (often wrong)

Layer 2: Investigation Clues

  • Contradictions in stories
  • Hidden connections between suspects
  • Timeline inconsistencies

Layer 3: Breakthrough Clues

  • The key realization that solves everything
  • Hidden evidence the culprit concealed
  • The true motive revealed

6. Adventure Content

Part 1: The Discovery

Setup: [How players encounter the mystery - hired, witness, stumble upon it]

Read Aloud: “[Description of the crime scene or initial situation. Set the mood - something is clearly wrong. Engage multiple senses. Who’s present? What’s the emotional atmosphere?]”

Features:

  • [Key detail that players should notice]
  • [Environmental element that sets the tone]
  • [NPC reactions to the situation]

Initial Investigation:

  • What Perception/Investigation reveals at various DCs
  • Who can be questioned immediately
  • What official presence exists (guards, authorities)

Outcomes:

  • Thorough Search: Players find surface clues, enough to begin investigation
  • Quick Look: Miss some clues but can return later
  • Transition: Which suspects/locations become available

Part 2: Suspect Interviews

Setup: Players track down and question suspects

Interview: [Suspect 1 Name]

Read Aloud: “[Description of where this suspect is found and their initial demeanor]”

Roleplaying Notes:

  • How they speak (nervous? Arrogant? Helpful?)
  • Physical tells when lying
  • What makes them open up

Key Questions to Anticipate:

QuestionTheir ResponseThe Truth
[Likely question][What they say][Reality]
[Likely question][What they say][Reality]

Insight/Deception DCs:

  • DC [X] to notice [specific tell]
  • DC [X] to catch them in a lie about [topic]

Interview: [Suspect 2 Name]

Read Aloud: “[Description of where this suspect is found]”

Roleplaying Notes:

  • [How to portray them]

Key Information:

  • [What they know that’s useful]
  • [How to get them to share it]

Part 3: The Investigation Deepens

Setup: Following clues to secondary locations, discovering contradictions

Read Aloud: “[Description of a key investigation location - perhaps the culprit’s secret meeting place, a hidden room, or evidence cache]”

Features:

  • [What makes this location significant]
  • [Hidden elements requiring skill checks]

Discoveries:

  • [Clue that eliminates a red herring]
  • [Clue that points toward the truth]
  • [Complication that raises stakes]

Outcomes:

  • Major Breakthrough: Players connect the dots
  • Partial Understanding: Some pieces fit, others don’t
  • Transition: The culprit becomes aware they’re being investigated

Part 4: Confrontation

Setup: Players have enough evidence to confront the culprit

Read Aloud: “[Description of the confrontation location - dramatic and appropriate for the showdown]”

The Confrontation:

  • How the culprit reacts when accused
  • What evidence they try to deny
  • When they resort to violence (if applicable)

Encounter: final_showdown

  • Tactics: [How the culprit fights or tries to escape]
  • Environment: [Factors that affect the confrontation]
  • Complications: [Third parties, time pressure, hostages]

Resolution Options:

OutcomeHow It HappensConsequences
JusticeCulprit captured and tried[What changes]
EscapeCulprit flees[Sets up sequel]
TragicCulprit dies or wins[Dark ending]
TwistBigger conspiracy revealed[Leads to more]

7. Escalation Timeline

If PCs Investigate Quickly:

  • Culprit gets nervous, makes mistakes
  • Additional evidence surfaces before it’s destroyed
  • Witnesses become more helpful

If PCs Investigate Slowly:

  • More crimes occur
  • Evidence disappears
  • Culprit grows bolder
  • Witnesses get threatened or killed

8. DM Notes

Pacing

  • Let players theorize - don’t rush to the answer
  • Drop clues at a steady pace, accelerate near the end
  • If players are stuck, have a new incident occur
  • The “aha moment” should feel earned

Running Investigations

  • Present information, don’t solve the puzzle for them
  • Reward creative questioning and approaches
  • Have NPCs react to player theories (some correctly, some not)
  • Use Investigation vs. Insight for different discoveries

Common Pitfalls

  • Players fixate on wrong suspect: Have that suspect do something that proves innocence (while players watch)
  • Players are completely stuck: A new witness comes forward, or the culprit makes a mistake
  • Players guess too quickly: Add a layer - they’re right about who but wrong about why

Scaling

  • Shorter Mystery: Reduce suspects to 2, compress timeline
  • Longer Mystery: Add more layers, false conclusions, rival investigators

9. Connections

From Previous Module

[What plot threads or relationships carry forward]

To Next Module

[What this mystery reveals about larger plots, or new hooks discovered]

Campaign Themes

[How this mystery reinforces overarching campaign themes]


10. Post-Module Notes

What Happened

  • Who did players suspect first?
  • Which clues did they find/miss?
  • How did they confront the culprit?
  • What was the final resolution?

Continuity Notes

[Important facts for future modules - relationships changed, secrets learned]

Player Engagement

[Which investigation techniques worked well? What to do differently?]


Mystery Maintenance Checklist

  • All suspects have believable motives
  • Red herring is compelling but disprovable
  • Each crucial clue can be found multiple ways
  • Timeline makes logical sense
  • Culprit’s plan has a fatal flaw
  • Players can solve without lucky guesses
  • Failure leads somewhere interesting (not dead end)

Status: [Planning / Ready / Active / Complete] Started: [Date] Completed: [Date]