When me and my friend played M.U.L.E. on the C64 we did collusions.  The computer human players always had an advantage.  Working together gave the colony a higher rating in the end.

C64.  Me and my friend Darryl used to play it.  The game took about 1.5-2 hours but was a lot of fun.  Our colony once got one of the higher scores.  We had to do some colusions to get there though.