Buckminster R. Fuller's World Game and ModelEarth.
(The bellow text is to be understood as a draft; not firm enough in any conclusions, but good enough, perhaps, to initiate a discussion?)
Buckminster R. Fuller's World Game is offering a vision of a world based mostly on BRF's ideas of what this world should look like, whereas ModelEarth is offering a way of reconciling virtually of all any such ideas, by any and all, of what the ideal world should look like, based on creating desired results as outlined in Robert Fritz's Path of Least Resistance (Fritz 1984), applied to creating of a collectively held vision of an ideal world.
In Buckminster R. Fuller's World Game the vision of a better world is based on solutions suggested by individuals and teams that concentrate on solving the world's problems and the vision thus shaped is based, mostly, on BRF's ideas and inventions; however Buckminster R. Fullers vision of a sustainable future is not shared by all who share the Earth.
Model Earth proposes to reconcile the differences that there are among all and any such ideas in models (or by using any other expedient means) in order to prevent all the waste (material, life) that happens normally when these differences reconcile in real life, causing real damage.
I find it hard to find any records of instances of World Game played where it would be clear to see what criteria were used to decide which entries would be more successful than others.
But from what I could see from the material that I found on the Internet, it would seem that in World Game the actions meant to improve this world are motivated and driven by the unsatisfactory state of the world, and not by a commonly held vision that would be optimally acceptably by all who share the Earth.
The above is based on what I could find about "World Game" in R. Buckminster Fuller's Critical Path (St. Martin Press, New York, N.Y. 10010, 1981, ISBN 0-312-17488-8), Thomas T.K. Zung's Buckminster Fuller: Anthology for the New Millennium (St. Martin Press, New York, N.Y. 10010, 2001, ISBN 0-312-26639-1), in R. Buckminster Fuller's Utopia or Oblivion: the prospects for humanity, Chp. 6.: The World Game--How to Make the World Work (p157) (The Overlook Press, R. F. D. 301, Woodstock, N. Y. 12498, 1969, SBN 0-87951-X), my correspondence with the Buckminster Fuller Institute:
ModelEarth, BFI - Correspondence,
and my correspondence with Medard Gabel.
ModelEarth objective is to first collectively design (in a model) the ideal state of affairs of any social entity regardless of its size (from the very minimally sized community to the whole global community) before starting devising ways of achieving that ideal state. This approach follows the idea that it is easier to achieve something that we know what it is, rather than trying to make things ideal, without first knowing what the "ideal" actually should be.
In ModelEarth the actions are motivated and driven by the desire to get as close as possible to the ideal presented in the model.
In ModelEarth it is ideas inputted by anyone that compete for the ideal design, not individuals.
Modeling could be employed in designing an ideal state of being for any social entity of any size--from a group of humans (conflict resolution) to the whole global society.
In order to achieve an ecologically and socially sustainable future we, collectively, have to first decide what a "sustainable" future should be. Then, after we know what a sustainable future agreeable to all should be, we can decide the steps how to achieve this ideal.
If we don't agree on what our collective "sustainable" future should be, reconciling differences in real life would be very costly (in terms of over-using resources, even in terms of loss of life)--this could even prevent us from achieving sustainability ever.
The concept of designing the future co-operatively is based on what I understand to be Mahayana (please see modelearth.org/mahaecosoc.html ) and The Path of Least Resistance by Robert Fritz.
(Salem, MA, DMA, Inc., 1984, ISBN: 0-930641-00-0).
It could, perhaps, be argued that by using RBF's approach one would eventually arrive at the same results as by using the approach of ModelEarth concept. The main difference would be that in World Game, despite continuous solving of problems by "playing", the differences among the Earth inhabitants would continue resolving in real life with costly results creating an endless stream of problems needing to be addressed and "played" in World Game continuously, whereas most such problems would be resolved "in modelo" by the ModelEarth approach without any real life consequences.