BECMI is essentially the same game, just re-edited and with the promised companion rules, plus masters, and immortals rules added. So, yeah they're included. (including Rules Cyclopedia, too!) I'm not familiar with any of the third party rewrites.Is OSE topical, or are we limiting discussion to the original B/X? Sadly, the original was before my time. I grew up in the ’80s, but I was more into video games (though we did play HeroQuest).