click to skip navigation Education for Sustainable Development Toolkit, version 2 point o
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Author's note
What is E S D?
Reorienting Education
Localizing the Global Initiative
Challenges and Barriers to E S D
Community Sustainability Goals
Case Study: Toronto, Canada Board of Education
Managing Change
Public Participation
Concluding remarks
Tools to Introduce the Concept of Sustainable Development
Tools to Create Community Goals
Tools to Reorient Education to Address Sustainability
Tools for Managing Change
Web resources

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This hands-on exercise puts participants in the middle of an easy-to-understand sustainability dilemma.


To introduce participants to the concept of sustainable development.


For a closer examination of the concept of sustainable development, see also the exercises Seeing Your Community Through a Sustainability Lens and S.E.E. the Links.

Group size: 4 to 36 participants.

Time Needed: 30 minutes


  • A large number of white pebbles.
  • A large number of red pebbles (or any contrasting color).
  • An opaque bag for each community.


  1. Divide the group into communities of four.
  2. Place 16 white pebbles in an opaque bag for each community.
  3. Give each community member a large handful of red pebbles.
  4. Choose the most culturally appropriate scenario from the following five scenarios. The scenario illustrates that by overusing a resource, that resource or another is damaged in some way. Share the scenario with the participants.
    • White pebbles represent one parcel of land farmed; red pebbles represent use of chemical fertilizer, herbicide, and pesticide.
    • White pebbles represent one parcel of land used to graze animals; red pebbles represent loss of grazing vegetation and over production of manure.
    • White pebbles represent one day's catch from a fishing vessel; red pebbles represent population growth of less-desirable species.
    • White pebbles represent travel by air; red pebbles represent exhaust pollution from airplanes.
    • White pebbles represent products made from a factory; red pebbles represent pollution to air and water by that factory.
  1. Explain the rules of the game:
    • Participants draw one or more pebbles from the bag each turn.
    • Each community member must draw at least 1 white pebble from the bag per round to survive. It does not matter how many red pebbles are drawn.
    • If a participant does not draw a white pebble she/he "dies" and does not continue to play.
    • Each community member may take as many pebbles as desired from the bag.
    • At the end of each round, the white pebbles in each community's bag are counted; exactly that many white pebbles are added to the bag.
  1. Rounds 1 and 2: First generation (the present). For each white pebble a participant takes, one red pebble is placed in the team's bag immediately.
  2. Rounds 3 and 4: Second generation (your children). For each white pebble a participant takes, three red pebbles are placed in the bag immediately.
  3. Rounds 5 and 6: Third generation (your grandchildren). For each white pebble a participant takes, three red pebbles must be placed in the bag immediately.
  4. Discuss how the game progressed.
    • Who had the advantage? Why?
    • Why did participants take as many pebbles as they did?
    • How did the actions of the first generation impact the third generation? Is this fair?
    • During what round was the "fatal move" made (the act that caused the demise of the system?) How did this affect the rest of the game play?
  1. Give the communities the chance to play again, without the bags, so that participants can monitor the communal resource and the pollution. The same rules apply.
  2. Discuss how this game progressed.
    • Were communities able to sustain the resource so that the third generation had as little pollution/overuse as the first generation?
    • Did any communities opt to limit: use of chemicals/amount of grazing/catch size/air travel/pollutants created?

    How much communication did it take to sustain the resource?

Observations on playing Drain or Sustain II

In the first two rounds, participants will have no trouble surviving, and may even show greed by taking four or more white pebbles. It becomes obvious that the community member who reaches into the bag first has an advantage over the other community members.

In rounds 3 and 4, participants will begin to take larger handfuls from the bag, especially at the end of Round 4. They will be concerned when someone gets a large number of white pebbles, as that means fewer white pebbles and many more red pebbles for the next participant.

In rounds 5 and 6, the participants begin to "die off" (be put out of business, be forced to leave the farm, etc.). Participants take huge handfuls of pebbles in fear that they might not survive. By now it becomes obvious that the common resource is so polluted/overused that everyone loses.

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