Takes 20-30 minutes
A set of poker chips. 200 in four colours works fine, the less you have in more limited colours, the harder the task will be.
Give the group a box of poker chips. Tell them
You have 20 minutes to create a means of transferring a message from one half of the group to the other using only the chips placed on the table.
No paper or pencils are permitted.
After 20 minutes I will split the group in two and half of you will be asked to leave the room. I will give the remaining participants a 20-30 letter message that may involve letters or numbers but no punctuation, which you must pass to the other group using only the poker chips"
Facilitate the creation of the code. This is where the bulk of the team dynamics and personal development takes place as the participants try to refine their aim, then develop the code and finally to ensure that everyoe understands the code.
Use whatever means you like to capture this discussion, we have successfully used video, notes, phrases used jotted on a blackboard and having observers taken from within the group.
When they have a code, split the group into two and send half out of the room. Give the other half a short (20-30 letter) message on a piece of paper and help them encode it.
The messages are best if they have several words, and aren't too easy to guess once you have 2-3 of the words. We've used short Shakespeare quotes and the names of the building we are in.
Invite the other half back in to decode it and ensure that there is no cheating.
Swap the two halves of the group over and try with a different message.
We have used variants of this task in a number of places.
Doing it outside makes it a much more physical, tactile task and adds whole new areas of discussion such as role allocation "You go and collect black stones" or even "What shall we use?".