Introduction

Most incident simulations live in documents, slide decks, or abstract diagrams. That works—until you’re dealing with a truly multi-threaded outage: multiple services failing at once, conflicting priorities, race conditions between fixes, and cascading side effects you didn’t anticipate.

In those moments, incident diagrams often feel too flat. We need something more tactile and spatial.

Enter the Cardboard Incident Rail Labyrinth: a hands-on, tabletop-style exercise where you physically build tangled paper tracks to represent concurrent incident threads. Teams then "run trains" (workstreams, mitigations, and decisions) along these tracks to see what collides, what gets blocked, and what quietly derails.

This format turns abstract, concurrent incident scenarios into a concrete puzzle. It helps teams reason about dependencies, race conditions, and cascading failures in a way that’s both playful and brutally honest.

What Is the Cardboard Incident Rail Labyrinth?

At its core, the Rail Labyrinth is a tabletop exercise with craft supplies.

You’ll need:

• Cardboard or a large table
• Paper strips (tracks)
• Sticky notes or small cards (trains, signals, constraints)
• Tape or pins
• Markers

Each paper track represents a thread of the incident: an outage in a specific service, a recovery workstream, a governance process, or an external dependency. As you layer and intersect these tracks, you build a physical map of a multi-threaded outage and your organization’s response.

Instead of a static architecture diagram, you get a living labyrinth that everyone at the table can see, touch, and modify.

Why Make Incidents Physical?

Multi-threaded outages are cognitively hard:

• Dependencies aren’t obvious
• Timelines overlap
• Ownership is unclear
• Decisions ripple in unexpected ways

On a whiteboard, this often becomes a chaotic web of arrows. In chat, it becomes a scrollback blur. The Labyrinth solves this by:

1. Making concurrency spatial
   Parallel tracks, merges, and crossings let teams see simultaneous work and contention.

2. Highlighting race conditions
   When two paper trains vie for the same track section or resource, you literally can’t move both forward. You must decide.

3. Exposing cascading failures
   You can visually extend the impact of a blocked track—downstream trains stop, reroute, or pile up.

4. Aligning everyone’s mental map
   Stakeholders from engineering, operations, legal, comms, and leadership can point at the same physical thing and reason together.

The result is a concrete, shared model of a complex outage that’s more intuitive than a slide deck and more dynamic than a static tabletop script.

Designing Clear Objectives (Like a Real TTX)

The Rail Labyrinth shouldn’t just be arts and crafts. Like any good Tabletop Exercise (TTX), it needs explicit objectives that tie back to organizational capabilities.

Before the session, define what you’re testing. For example:

• Communication:

  • How quickly and accurately does information flow between parallel tracks?
  • Does anyone own cross-track coordination?

• Coordination:

  • What happens when multiple teams need the same resource (e.g., DB access, a rollback window, or the incident commander’s attention)?

• Recovery and continuity:

  • How do you prioritize between customer segments or regions?
  • What gets sacrificed first when capacity or time is constrained?

• Governance and risk:

  • When do legal, compliance, or PR need to “jump on the track”?
  • Are there clear triggers and decision rights?

You can express these as capability-based goals, such as:

"Evaluate our ability to coordinate three overlapping incidents that share a critical database and two on-call teams, while maintaining regulatory communication requirements."

These objectives inform the labyrinth design, the scenario script, and the debrief questions.

Building the Labyrinth: A Step-by-Step Outline

Here’s a practical way to set up and run a Rail Labyrinth session.

1. Choose a multi-threaded scenario

Pick (or invent) a scenario that would genuinely stretch your organization:

• A regional cloud provider outage impacting multiple services
• A data corruption incident plus a simultaneous spike in traffic
• An internal auth failure overlapping with a security incident
• A holiday-peak degradation colliding with a vendor failure

Write 3–5 incident threads that will run in parallel. Each thread has:

• A starting condition
• Key events and constraints
• One or more desired outcomes

2. Map threads to tracks

Give each thread its own paper track, labeled clearly (e.g., "Payments Degradation", "Login Outage", "Regulatory Reporting").

Add intersections where:

• Multiple threads share a resource (e.g., a database, an SRE team)
• A decision affects more than one track (e.g., feature flags, traffic routing)
• External stakeholders converge (regulators, major customers, press)

You can draw small icons or use colored tape to indicate resource contention zones or high-risk crossings.

3. Assign roles and trains

Participants choose or are assigned roles:

• Incident commander / incident managers
• Tech leads / on-call engineers
• Support and customer success
• Legal, compliance, and comms
• Executives or business owners

Each team gets train pieces (cards or tokens) representing:

• Actions (e.g., "Roll back release", "Throttle traffic")
• Decisions (e.g., "Disclose incident to customers now/later")
• Requests (e.g., "Ask SRE for temporary capacity")

Trains move forward along the tracks as time progresses and decisions are made.

4. Run the exercise in time segments

Simulate time in rounds (e.g., 10 minutes per round of “simulated time”). Each round:

1. The facilitator reveals new events (e.g., "Cloud region X degraded", "Customer reports data inconsistency").
2. Teams decide how to move their trains: accelerate, hold, reroute, or add new ones.
3. Physical constraints apply: if two trains need the same segment at the same time, they can’t both pass. You must:
   • Sequence them
   • Add another track (spin up a new team or resource)
   • Or choose to delay or drop something

The cardboard and paper force trade-offs that often stay hidden in pure discussion.

5. Capture decisions and observations in real time

Use sticky notes near the tracks to document:

• Key decisions and rationales
• Points of confusion about roles or ownership
• Bottlenecks and conflicts
• Areas where the play diverges from existing plans

This becomes raw input for your post-exercise analysis.

Stress-Testing Plans and Surfacing “Theory Gaps”

Like classic TTXs, the Labyrinth is meant to evaluate and stress-test your incident response and business continuity plans, not just entertain.

Some patterns to look for:

• Plan vs. reality mismatch
  Do teams repeatedly ignore or bypass documented procedures because they don’t match how work actually happens?

• Role ambiguity
  Are there stretches of track where no one knows who “owns” the next move? Do multiple people try to drive the same train?

• Coordination breakdowns
  Are tracks that should be synchronized (e.g., comms and technical remediation) moving out of phase?

Beyond procedural gaps, the Labyrinth often reveals "theory gaps"—places where your organization’s mental model of multi-threaded outages simply doesn’t exist or is inconsistent.

Examples of theory gaps:

• No shared understanding of what "multi-incident mode" looks like
• Conflicting intuitions about which customers or services get priority when everything is on fire
• Vague or absent guidance on when to pause new deploys, freeze changes, or declare an incident-of-incidents

These theory gaps are similar to what you find in scientific fields that lack a unifying predictive model: people operate from local heuristics, and surprises are frequent.

The Labyrinth externalizes those hidden assumptions so you can:

• Refine your incident taxonomies and playbooks
• Improve architecture documentation around dependencies
• Develop shared language for trade-offs and prioritization

Building Confidence in a Low-Risk, Game-Like Environment

Real incidents are stressful. They carry reputational, financial, and emotional weight. That stress makes it harder to learn in the moment.

The Cardboard Incident Rail Labyrinth deliberately lowers the stakes:

• It feels like a game, not a test
• Failure is expected and safe
• Participants can pause, rewind, or replay segments

Within this environment, people can experiment with:

• Taking on new roles (e.g., engineers trying incident command)
• Challenging assumptions about sequencing and ownership
• Trying alternative strategies and seeing how the trains move

Over time, this rehearsal:

• Builds organizational capacity: more people understand how multi-threaded incidents really play out.
• Increases individual confidence: staff are less likely to freeze or defer in complex incidents, because they’ve already “driven trains through the maze” before.

Turning Insights into Action

A Rail Labyrinth session only pays off if you convert insights into changes.

After the exercise:

1. Hold a structured debrief

   • What surprised you?
   • Where did trains pile up or collide?
   • What decisions felt hardest, and why?

2. Map findings to artifacts

   • Update runbooks and playbooks
   • Adjust escalation paths and role definitions
   • Clarify policies for multi-incident prioritization

3. Refine your mental models

   • Write down new concepts or patterns observed (e.g., "incident-of-incidents mode", "shared bottleneck zones")
   • Incorporate them into training and onboarding

4. Schedule the next iteration

   • Revisit similar scenarios with improved plans
   • Gradually increase complexity: more tracks, tighter constraints, new stakeholders

Conclusion

Multi-threaded outages are no longer edge cases; they’re a defining feature of complex, interconnected systems. Yet many organizations still think about incidents in linear, single-threaded terms.

The Cardboard Incident Rail Labyrinth offers a way to bridge that gap. By hand-building tangled paper tracks and navigating them together, teams turn abstract concurrency into a concrete problem they can see, touch, and reason about.

The outcome isn’t just a fun workshop. It’s a clearer view of:

• How your organization actually coordinates under stress
• Where your incident and continuity plans hold up—or fall apart
• Which mental models you’re missing for true multi-threaded resilience

With a bit of cardboard, paper, and intention, you can help your teams practice the hardest incidents before they happen—so that when the real labyrinth appears, they’ve already learned how to find their way through.