Around the year 1990, I played the game Empire on a VAX/VMS system. It was a turn-based, text-based-map wargame that later inspired Civilization and Xconq.
What was particularly memorable about this game was how predictable its random number generator was. If I performed a series of attacks during my turn, there was a certain pattern to which ones would succeed or fail. The pattern was a repeating cycle of maybe 8 to 20 attacks. After discovering the pattern, I planned my attacks for each turn, making sure I had sacrificial units for the attacks that were bound to fail. I could easily defeat the computer, which apparently did not have my insight.
What algorithm did Empire use to determine the outcome of attacks? Was it simply a linear congruential RNG (or the least significant bits thereof)? Something worse? How often would it produce a repeating pattern?