Strategy game
21 coins
A strategic Nim game with the whole group - outsmart the computer and grab the last coin to win.
What is the 21 coins game?
21 coins is a classic logic game (the mathematical game of Nim) in a browser-playable form. Twenty-one gold coins sit on the table, and the player and the computer take turns removing 1, 2 or 3 coins. Whoever takes the last coin wins.
The secret lies in how many coins you leave for your opponent. You can play it solo or run it as a live session: participants join with a code or QR code and play their own rounds while you see who managed to beat the computer.
Features
Key capabilities
21 coins on the table
Drag coins into your chest - 1, 2 or 3 each turn. Whoever takes the last one wins.
Computer opponent
You play against a machine that plays optimally - beating it means discovering the strategy.
Strategic thinking
The game teaches backward planning and finding the winning number of coins to leave behind (the Nim principle).
Drag-and-drop controls
Intuitive grab-and-drop of coins into the chest - works with mouse and touch.
Live session with ranking
Run it for the group: participants join with a code or QR code while you watch results and wins.
Training mode
Before you start a session, play a few rounds yourself - the training run on the host console lets you learn the strategy you will later reveal to the group.
Step by step
How it works
Launch the game
Open 21 coins solo or start a session and show the code and QR code to the group.
Learn the rules
There are 21 coins on the table; the player goes first and takes 1–3 coins per turn.
Take turns
Drag coins into the chest, alternating with the computer, until the table is empty.
Grab the last coin
Whoever takes the last coin wins - in a session the results feed the ranking.
Use cases
What it’s good for
- A logic warm-up at the start of a session
- An introduction to strategy games and Nim theory
- Practising backward thinking and planning moves
- A short group contest with a wins ranking
- A short logic game to warm the group up
- Show strategic thinking on a very simple example
- A task that teaches planning several moves ahead
Training by Octigo
Want this run as a full training?
You are free to run our games and simulations on your own. But if you would like us to deliver a complete training, with a professional debrief and the concepts behind the “21 coins” simulation explained in depth, get in touch. Octigo is a professional training company with 20 years of experience and many awards for its simulations.
- 20 years of experience in corporate training
- Award-winning training simulations
- A professional debrief and takeaways after the session
- A programme tailored to your goals and your team
Prefer to write to us directly? szkolenia@octigo.pl
Try “21 coins” in Verbalu
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