reverse engineering

A friend of mine was going on about his plans about doing stuff with the 1996 game "Risk", and I asked him if he had the source code so I too could look at it, since it was old I assumed it was made open or something, but turns out it wasn't, then I asked him how the fuck was he going to mess with it, then he said he was going to reverse engineer it, and I said lol u can't do that, he seemed in doubt - but now I've been thinking, why the fuck not? (I'd just told him he couldn't do it to be a dick)

Does anyone have actual knowledge on the specifics? Would it be possible?

>>10
If it's a Linux-style clone (in 2D, with poor graphics, Mario replaced by a penguin, with zero attention to detail, and ultimately unfinished) then sure.