Free lean training game · Play online or print the card
The Penny Game: see why small batches beat big ones.
The penny game is the classic lean exercise for teaching batch size, flow, and work-in-process — four workers, twenty coins, and a stopwatch that does the arguing. Run it right here with a facilitator mode built for projecting to a room, play a seat yourself, or print the free card and run it at a table.
- Time
- 15–20 min
- People
- 1 to a full room
- Teaches
- One-piece flow · WIP · lead time
- Cost
- Free, no signup
Projecting for a workshop? Choose “Run it for a group” — it stops for predictions, keeps a round scoreboard, and puts a facilitator question bank one click away. The ⛶ button goes fullscreen.
What is the penny game?
The penny game (sometimes called the coin game or coin-flip game) is a hands-on lean manufacturing training exercise that demonstrates the effect of batch size on speed, quality, and the experience of the people doing the work. Four workers sit in a row. The first worker flips 20 coins and passes them to the next worker, who flips them and passes them on, until all 20 clear the last worker. The only thing that changes between rounds is the batch rule — how many coins a worker must finish before passing them downstream.
In round 1, coins move in one batch of 20. By round 4 they move one at a time — one-piece flow. Same people, same coins, same flips. The first coin is delivered roughly 15× sooner and the whole batch finishes about 3.5× faster. Nobody worked harder. Only the system changed — which is the whole point, and why the game has been a staple of continuous improvement workshops for decades.
How to run the penny game
What you need
- 20 coins, all heads up to start
- 4 workers seated in a row at one table, plus a timekeeper and a spotter
- 2 stopwatches — one for the first coin delivered, one for all 20
The rounds
- Round 1 — big batch: each worker flips all 20 coins, then passes the whole pile.
- Round 2 — half batch: pass after 10 coins.
- Round 3 — small batch: pass after 5.
- Round 4 — one-piece flow:pass every coin as soon as it's flipped.
Before round 1, ask the room to predict how much faster round 4 will be. Most groups pick the right winner — and underestimate the margin by 3–5×. That gap between what people expect and what the stopwatch says is where the learning lives.
What will happen
| Round | Pass after | First coin | All 20 | Biggest pile |
|---|---|---|---|---|
| 1 · Big batch | 20 | 5:05 | 6:40 | 20 |
| 2 · Half batch | 10 | 2:35 | 4:15 | ~19 |
| 3 · Small batch | 5 | 1:20 | 2:55 | ~9 |
| 4 · One-piece flow | 1 | 0:20 | 1:55 | 1 |
Reference times at 5 seconds per flip. Your room will be faster — the ratios hold: first delivery ~15× sooner, done ~3.5× faster, same people, same work.
What the penny game teaches
- Lead time lives in the waiting, not the working. Every coin gets flipped for the same few seconds. In the big-batch round, coins spend over 95% of their time sitting in a pile.
- WIP is the delay. The pile between two workers is the lead time, made visible. In your own process, the pile is a full inbox, a stack of parts, or a queue of tickets.
- Batching delays quality feedback. If a worker flips coins wrong in round 1, all 20 are wrong before anyone downstream can notice. In one-piece flow the first bad coin is caught immediately.
- The system, not the people. Round 4 wins without anyone flipping faster. Improvement came from changing the batch rule — a lesson that transfers to any lean or continuous improvement effort.
Variations worth running
- The hidden defect.Secretly tell worker 2 to flip coins upside-down; only worker 4 may inspect. Count how many bad coins exist when the first one is caught — in round 1 it's all of them. (Built into the simulation as a toggle.)
- The uneven line. Have worker 3 flip each coin twice. Watch where the pile forms — you have just built a bottleneck.
Debrief questions
- Where did the coins spend most of their time — being flipped, or waiting?
- What does the pile between two workers represent in our process?
- If a coin had been flipped wrong in round 1, when would we have found out — and how many coins would already be wrong?
- How did it feel to be the last worker in round 1?
- Make it stick: where in our work are we running round 1 — in parts, forms, tickets, emails, or approvals? Batching is not just a factory habit.
Print it and run it at a table
The Penny Game — printable facilitator card
One page, print-and-go: setup diagram, the four rounds with reference times, both variations, and the debrief script. Part of the free Kaizumi lean game library — one email unlocks all four cards.
Letter-size, print-ready, readable in black and white.
Penny game FAQ
How long does the penny game take?
15–20 minutes including the debrief: about two minutes of setup, four short rounds, and five to ten minutes of discussion. The online simulation runs a full session in about ten minutes at 8× speed.
How many people do you need?
Five or six for the tabletop version: four workers, a timekeeper, and a spotter. With the online facilitator mode, one person can run it for a room of any size — or for a remote team on a video call.
Do I have to use pennies?
No — any 20 identical objects you can flip work: coins, cards, poker chips, sticky notes. The batch rule is the game; the coins are just the work.
What's the difference between the penny game and the One-Piece Flow Simulator?
The penny game is the classic four-worker tabletop exercise — rounds, stopwatches, and a debrief. The One-Piece Flow Simulator is a continuous factory simulation with factory, café, and office scenarios. Run the penny game to create the aha; use the simulator to explore it further.
Is this really free?
Yes. The simulation runs in your browser with no signup. The printable card asks for an email address, and the whole lean game library comes with it.