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The marshmallow challenge is more than just a simple team building activity—it's a powerful engineering challenge that reveals how teams collaborate, prototype, and solve problems under pressure. Whether you're facilitating a corporate workshop, running a STEM activity for students, or looking for an engaging icebreaker, this classic problem-solving activity delivers insights that spark meaningful conversations about innovation and teamwork.

In just 18 minutes, teams compete to build the tallest freestanding structure using only spaghetti, tape, string, and one marshmallow. The catch? The marshmallow must sit on top. What seems straightforward quickly becomes a lesson in iterative design, communication, and the dangers of overplanning. This guide provides everything you need to facilitate an impactful marshmallow tower challenge, including preparation checklists, variations, facilitation strategies, and our built-in interactive tool.

What is the Marshmallow Challenge?

The marshmallow challenge is a design-thinking exercise where small teams (typically 3-5 people) compete to build the tallest freestanding structure in 18 minutes using limited materials. The structure must support a single marshmallow on top without collapsing.

Each team receives identical materials: 20 sticks of spaghetti, one yard of tape, one yard of string, and one marshmallow. Teams can break the spaghetti, cut the tape and string, but they cannot modify the marshmallow. The structure must be freestanding—no attachments to tables, chairs, or ceilings.

Origins and the Tom Wujec TED Talk

Designer and innovation expert Tom Wujec popularized the marshmallow challenge through his influential TED talk, which has been viewed millions of times. Wujec studied hundreds of teams—from business school students to kindergarteners—and discovered surprising patterns about who succeeds and why.

His research revealed that business school graduates often perform worse than kindergarteners. Why? Business students spend too much time planning and executing a single design, saving the marshmallow for the final moment only to watch their tower collapse. Kindergarteners, meanwhile, prototype rapidly, test early, and iterate based on what works.

The marshmallow challenge has since become a staple collaboration game for design thinking workshops, leadership development programs, and STEM education worldwide.

Why the Marshmallow Challenge Works

This deceptively simple engineering challenge creates powerful learning moments that resonate long after the 18 minutes expire.

Reveals Real Team Dynamics

Unlike traditional team building activities where personalities can mask dysfunction, the marshmallow challenge exposes how teams truly operate. Within minutes, you'll observe natural leaders, facilitators, builders, and disengaged members. The time pressure and physical nature of the task make it difficult to hide behind hierarchy or credentials.

Teaches Iterative Prototyping

The marshmallow represents the weight of assumptions and untested ideas. Teams that build iteratively—testing early and often—consistently outperform those who plan extensively before their first attempt. This mirrors real-world innovation processes where rapid prototyping beats perfect planning.

Levels the Playing Field

The simple materials and straightforward rules make this activity accessible to everyone regardless of technical background. Engineers don't necessarily have an advantage over marketers or designers. Success depends on collaboration, communication, and willingness to fail fast and learn.

Sparks Genuine Engagement

There's something inherently engaging about building with your hands. The marshmallow challenge breaks down digital barriers and gets people physically working together. The competitive element adds energy, while the short duration maintains focus and momentum.

How to Play: Rules and Instructions

Running a successful marshmallow tower challenge requires clear communication of rules and consistent timing across all teams.

Materials Needed (Per Team)

20 sticks of dry spaghetti
One yard (91cm) of masking tape or transparent tape
One yard (91cm) of string
One standard-sized marshmallow (not mini marshmallows)
Scissors (shared between teams for cutting tape/string)

Step-by-Step Instructions

Form teams of 3-5 people. Four people per team is ideal for balanced collaboration.
Distribute materials to each team. Place all materials in front of teams before starting the timer.
Explain the challenge: Build the tallest freestanding structure that supports the marshmallow on top. The structure must stand on its own when time expires.
Clarify the rules:
- Teams have exactly 18 minutes
- The marshmallow must be on top and remain whole (no breaking it apart)
- Teams can break spaghetti and cut tape/string however they wish
- Structures must be freestanding (no attaching to furniture or people)
- Height is measured from the table surface to the top of the marshmallow
Start the timer and let teams begin. Circulate to answer questions but don't offer building advice.
Give time warnings at 10 minutes remaining, 5 minutes remaining, and 1 minute remaining.
Stop all building at 18 minutes. Teams must step away from their structures.
Measure heights of all standing structures. Only structures still standing after 10 seconds count.
Declare a winner and begin debrief discussion.

Timing Guidelines

The standard marshmallow challenge runs for 18 minutes, but you can adjust based on your context:

Quick version: 10-12 minutes for rapid team energizer
Standard version: 18 minutes (recommended for full learning experience)
Extended version: 25-30 minutes for deeper exploration and iteration

Challenge Variations

Adapt the marshmallow challenge to match your group's needs and learning objectives.

Virtual Marshmallow Challenge

Run this engineering challenge remotely by having participants gather materials at home before the session.

Materials alternative: If participants can't source spaghetti and marshmallows, try paper and tape (build tallest structure using 10 sheets of paper and tape), or popsicle sticks and playdough.

Virtual facilitation tips:

Send materials list 48 hours in advance
Create breakout rooms for team collaboration
Have teams demonstrate structures on camera
Use screen sharing to measure heights against a standard reference object
Record building sessions for playback during debrief

Hybrid Format

For groups with both in-person and remote participants:

Form mixed teams with both remote and in-person members
In-person team members build while remote members provide design guidance via video call
This creates additional communication challenges that surface valuable learning

Competitive Variations

Tournament style: Run multiple rounds with teams reconfigured between rounds. Track individual scores across rounds to find overall champion.

Budget constraint: Give teams fake money to "purchase" materials, adding resource allocation decisions to the challenge.

Mystery material: Add one surprise material (paper clips, rubber bands, index cards) that teams can optionally use.

Reverse challenge: Teams build the structure that can support the most marshmallows (instead of building tallest).

Educational Extensions

STEM focus: After the main challenge, teach basic engineering principles (triangulation, weight distribution, tension vs. compression) then run a second round to apply learning.

Design thinking workshop: Use the marshmallow challenge as the opening activity before teaching formal design thinking methodology.

Preparation Checklist

Use this checklist to ensure smooth facilitation.

Materials Preparation

Calculate team count and purchase materials accordingly (add 10% extra for mistakes)
Pre-measure and cut tape and string into one-yard lengths
Count out 20 spaghetti sticks per team
Package materials in bags or containers per team
Obtain measuring tape or ruler for height measurement
Prepare scissors (at least one pair per two teams)
Test marshmallow brand—some are too soft or too hard

Space Setup

Arrange tables so teams have adequate work space (minimum 4x4 feet per team)
Ensure tables are level and sturdy
Create sufficient distance between teams to prevent copying
Position timer/clock visible to all teams
Set up presentation area for instructions and debrief
Prepare camera/phone for documentation photos

Facilitator Preparation

Review Tom Wujec TED talk for facilitation inspiration
Prepare opening remarks explaining activity purpose
Create debrief questions aligned with learning objectives
Set up timer (use tool below or phone timer)
Plan time warnings strategy (verbal announcements or visual countdown)
Prepare prizes or recognition for winning team (optional)

Virtual and Remote Adaptations

The marshmallow challenge translates surprisingly well to virtual environments with proper preparation.

Pre-Session Logistics

Email participants a materials list at least one week before the session:

20 uncooked spaghetti strands (or substitute with toothpicks, straws, or chopsticks)
One standard marshmallow (or substitute with playdough, clay, or small apple)
Masking tape or clear tape
String or yarn
Scissors
Ruler or measuring tape

Request participants confirm materials receipt 48 hours before the session.

Virtual Platform Setup

Enable breakout rooms for team collaboration (4 people per room)
Create a shared timer visible to all participants (screen share or tool below)
Set up a "gallery" room where teams return to show finished structures
Prepare a shared document or chat for questions

Virtual Measurement Methods

Since you can't physically measure structures, use these approaches:

Have teams measure their own structures and report heights (honor system)
Ask teams to hold structures next to a common reference object (water bottle, smartphone)
Use screenshot measurements with on-screen rulers
Judge based on structural integrity and design creativity rather than pure height

Engagement Strategies for Remote Teams

Assign explicit roles within breakout rooms (builder, designer, timekeeper, materials manager)
Have teams name their structures and create team cheers
Use music during building time to maintain energy
Create a photo gallery of all structures in a shared slide deck

Built-in Interactive Tool {#game-tool}

Use our lightweight timer and scorekeeper to facilitate your marshmallow challenge with professional ease. The tool includes countdown timer with visual and audio alerts, team scorekeeper for tracking heights, and automatic winner calculation.

Tool Features

18-Minute Countdown Timer:

Large, visible display for in-person and virtual sessions
Customizable time warnings (10 min, 5 min, 1 min)
Start, pause, and reset controls
Optional audio alerts
Full-screen mode for projection

Team Scorekeeper:

Add unlimited teams with custom names
Record structure heights in inches or centimeters
Automatic ranking and winner display
Export results for record-keeping
Visual leaderboard display

Accessibility Features:

High contrast display for visibility
Keyboard navigation support
Screen reader compatible
Responsive design for mobile facilitation

How to Use the Tool

Before starting: Add team names and select your preferred measurement unit
During building: Start the countdown timer and monitor progress
At completion: Enter each team's structure height
Display results: Show the leaderboard and celebrate the winning team

The tool saves your settings locally, so you can prepare team names before your session begins.

Facilitation Tips for Maximum Impact

Your facilitation approach determines whether teams experience surface-level fun or deep learning.

Setting the Stage

Frame the purpose: Explain this is a collaboration game that reveals team dynamics and innovation practices. Avoid overselling—let the experience speak for itself.

Emphasize the marshmallow rule: Many teams forget the marshmallow has weight. Explicitly state the marshmallow must be on top and the structure must stand freely.

Create psychological safety: Acknowledge that structures will likely collapse. Failure is expected and valuable. The goal is learning, not perfect execution.

During the Challenge

Observe without coaching: Your role is to watch team dynamics, not help teams succeed. Resist the urge to give hints or building advice.

Take notes: Document interesting behaviors—who leads, how decisions are made, when teams test their structures, how teams respond to collapse.

Maintain energy: Use time warnings to build urgency. Consider playing upbeat music during building time.

Enforce rules consistently: If a team violates rules (attaching to ceiling, breaking marshmallow), provide immediate clear feedback.

Debrief for Deep Learning

The debrief conversation is where real learning happens. Ask powerful questions:

Process questions:

What was your team's approach? Did you plan first or start building?
When did you first test your structure with the marshmallow?
How did your team make decisions?
What would you do differently in a second round?

Learning questions:

What surprised you about this challenge?
How does this relate to projects at work?
What did you learn about your team's collaboration style?
Which behaviors helped or hindered your success?

Connection questions:

How is this challenge similar to innovation in your organization?
What's the "marshmallow" in your current projects—the untested assumption that might cause collapse?
How can we bring rapid prototyping mindset to our daily work?

Success Metrics and Learning Outcomes

Beyond height measurements, track these indicators of successful facilitation.

Team Performance Indicators

During the challenge:

Teams that test early and iterate (rather than planning extensively)
Balanced participation with multiple voices contributing ideas
Visible prototyping behavior (build, test, modify, repeat)
Constructive responses to structure collapses

Post-challenge:

Engaged participation in debrief discussion
Concrete connections between activity and work challenges
Specific behavioral insights teams want to apply
Requests to run additional rounds with new teams

Facilitator Success Markers

All teams understand rules and start building within 2 minutes
Multiple structures standing at time expiration (shows appropriate difficulty)
Rich debrief conversation with participant-led insights
Participants reference the activity in later sessions
Teams request similar problem-solving activities

Common Height Benchmarks

While heights vary widely, typical results include:

Winning structures: 20-36 inches (50-90 cm)
Average structures: 12-20 inches (30-50 cm)
Collapsed structures: 30-50% of teams (varies by group)

Kindergarteners average taller structures than business school graduates in Tom Wujec's research—a powerful conversation starter about expertise versus experimentation.

Frequently Asked Questions

How long does the marshmallow challenge take?

The building phase is 18 minutes, but plan 45-60 minutes total including introduction (5 min), building (18 min), measurement (5 min), and debrief discussion (15-20 min).

What if teams' structures collapse during building?

Collapsing is part of the learning experience. Teams can rebuild as many times as they want during the 18 minutes. Only the final standing structure (or lack thereof) is measured.

Can teams attach their structure to the table or wall?

No. Structures must be completely freestanding. They can rest on the table surface but cannot be taped or attached to furniture, walls, ceilings, or people.

What size marshmallow should we use?

Use standard-sized marshmallows (approximately 1 inch diameter). Mini marshmallows are too light and don't create the same challenge. Jumbo marshmallows work but are harder.

How many people should be on each team?

Teams of 3-5 people work best. Four people is ideal—enough for diverse perspectives without too many competing voices. Avoid teams larger than 6 people as some members become passive.

Can we run multiple rounds?

Yes. Running a second round after debriefing the first round demonstrates learning transfer. Teams typically perform significantly better in round two after applying insights.

What if we don't have spaghetti and marshmallows?

Alternative materials work well: paper and tape, popsicle sticks and playdough, straws and clay, or toothpicks and gumdrops. The key is using fragile building materials and a weighted top element.

Is this activity suitable for large groups?

Yes. The marshmallow challenge scales well from one team (3-5 people) to dozens of simultaneous teams. For groups over 30 people, ensure adequate facilitator support for clear communication and measurement.

How do we measure structures in virtual settings?

Ask teams to measure their own structures and report heights, have teams hold structures next to common reference objects for comparison, or evaluate based on structural design rather than pure height.

What's the learning objective of this activity?

Primary learning outcomes include understanding iterative prototyping, experiencing rapid experimentation versus overplanning, observing team collaboration patterns, and applying design thinking principles to real work challenges.

Getting Started with Your Marshmallow Challenge

Ready to facilitate this powerful team building activity? Follow this quick-start guide to run your first marshmallow tower challenge with confidence.

Your First Session Roadmap

Gather materials using the preparation checklist above (allow 30 minutes for setup)
Form teams of 4 people each as participants arrive
Introduce the challenge with enthusiasm and clarity (5 minutes)
Start the timer using the tool below and observe team dynamics (18 minutes)
Measure and celebrate all standing structures (5 minutes)
Facilitate debrief using the questions provided above (15-20 minutes)
Connect to work by asking how insights apply to current projects (5 minutes)

Before Your Next Meeting

The marshmallow challenge works beautifully as a kickoff activity for project teams, strategy sessions, innovation workshops, leadership development programs, STEM education classes, or corporate retreats.

Schedule 60 minutes in your agenda, gather simple materials, and prepare for surprising insights about how your team collaborates under pressure. The conversations sparked by this engineering challenge often prove more valuable than the building itself.

Use the interactive tool below to manage timing and scorekeeping like a professional facilitator. Your teams will appreciate the clear structure and you'll deliver an engaging problem-solving activity that participants remember long after your session ends.

Start building better teams—one marshmallow tower at a time.