(
Warning! The following writeup contains opinion. People who argue about what
Wolverine eats for breakfast, actually play
tabletop games, don't
floss regularly, etc. should look away now.)
I had to chuckle slightly at Raistlin's writeup above, specifically the line "cheap ripoffs that steal the ideas of the original BattleTech." This is particularly ironic as FASA's entire giant robot operation came about in the late 1970's as a reaction to the popularity of Japanese mecha comics, animated shows and (most lucratively) model kits.
Collectors were keen to snap up anything Gundam-related, but there was little attention paid to the plots and back story surrounding these items (probably because there was a scarcity of translated material at the time). Seeing a niche, FASA created their own mechs (which, IMO don't hold a candle to the exceptionally stylish Japanese originals) and penned a fantasy backstory, putting it all together in a tabletop strategy game which became very popular.
Twenty years later, Battletech now seems like a legitimate 'universe' in its own right, even though the mechs still look like Volvos. Incidentally, the first edition of Battletech was first published with the name BattleDroids, but George Lucas (hey, another guy stealing stuff from the Japanese!) was not overly pleased. So now you know.