  We introduce two three sided adaptative systems as toy models to mimic the
exchange of commodities between buyers and sellers. These models are simple
extensions of the minority game, exhibiting similar behaviour as well as some
new features. The main difference between our two models is that in the first
the three sides are equivalent while in the second, one choice appears as a
compromise between the two other sides. Both models are investigated
numerically and compared with the original minority game.
