Just to clarify: sharing and gifting are two different things -- we can't gift games we already own so, for someone to gift you BG2, they'd have to buy a separate copy for you and mark it as a gift for you when they finalize the purchase. Sharing GOG.com games is of course quite easy because of the lack of DRM, but there is a kind of "code of honor" to it that the community tends to follow out of respect for the site and their business model.
Here's a quote taken from a
post TheEnigmaticT, explaining it quite well:
The basic concept of how we ask you consider sharing a game is to treat it like a book or CD. Of course you can loan your buddies or family members your book, but while they're reading it, you can't. Once they're done with it, when they give it back you're free to play it again.
Of course, we don't have any DRM, so you can make your own decisions on this and we have no way of checking in on you or enforcing that, but that's the rule of thumb that we use for sharing a game you've purchased on GOG.com.
