The Marshmallow Challenge

How to Play

Setup

1. Group participants into teams of 3–5. If you have a large group, create multiple teams and have them work simultaneously.
2. Provide each team with: 20 sticks of dry spaghetti, 1 standard marshmallow, 1 yard/meter of masking tape, 1 yard/meter of string, and optionally 1 pair of scissors for cutting tape/string. Have a measuring tape or ruler for judging.
3. Ensure each team has a flat workspace. Mark a build zone per team with painter’s tape if space is tight.
4. Explain the objective: Build the tallest freestanding structure that supports the marshmallow on top before time runs out.
5. Set a visible countdown timer for 18 minutes and designate a facilitator/judge to enforce rules and measure.

How to Play

1. Start the 18-minute timer. Encourage teams to spend no more than 1–2 minutes planning before building.
2. Teams construct their structures using only the provided materials. They may break spaghetti and cut tape/string.
3. Emphasize rapid prototyping: place the marshmallow on early and iterate so teams can learn how weight affects stability.
4. Give time checks at 10, 5, and 2 minutes. Remind teams that the structure must stand on its own at the buzzer.
5. When time expires, call “hands off.” No one may touch or support their structure.
6. Measure from the tabletop (or floor, if building on the floor) to the highest point of the marshmallow. The structure must stand unaided for at least 5 seconds to qualify.
7. Announce the winner and briefly debrief key lessons about collaboration, prototyping, and assumptions.

Rules

1. The structure must be freestanding—no anchoring to tables, walls, chairs, or people. It must support the marshmallow on top.
2. The entire marshmallow must be on top. Do not cut, compress, eat, or hollow it out.
3. Use only the provided materials. Breaking spaghetti and cutting tape/string is allowed; additional supplies are not.
4. Height is measured vertically from the surface to the top of the marshmallow. If it falls during measurement, the last stable height counts; if none, the team scores zero.
5. No touching or stabilizing after time is called. Any contact disqualifies the measurement.
6. Safety: Be mindful of sharp spaghetti ends and scissors. Keep the area tidy and clean up afterward.

Tie-breakers (choose one in advance):

• Earliest time a team achieved a standing, marshmallow-topped structure within the round.
• Tallest structure that remains standing for 30 seconds.

Tips

• Put the marshmallow on early; it’s heavier than it looks. Iterate quickly with small tests.
• Assign light roles: builder(s), cutter, stabilizer, timekeeper/measurer.
• Favor wide bases, triangles, and guy-lines with string for stability.
• Use small tape joints to conserve tape; bundle spaghetti to create stronger columns.
• Communicate constantly, test often, and adapt fast.

Variations

• Silent Start: No talking for the first 5 minutes to emphasize nonverbal collaboration.
• Resource Twist: Reduce tape or string, or add a “budget” and auction extra materials.
• Sprint Rounds: Three 5-minute sprints with brief retros between; final sprint determines winner.
• Kids/Youth Version: Shorten time to 12–15 minutes, allow mini-post-it flags for visibility, and emphasize experimentation.
• Remote: Have participants build with household items on camera (e.g., spaghetti, tape, marshmallow or similar). Submit photos for measurement; use a shared countdown timer.
• Debrief Prompts: When did you add the marshmallow? What assumptions surprised you? How did roles and communication help or hinder?