Not only implemented already, but also as a possibility in the settlement creation. The desperation in a post-apocalyptic world seems like a strong growing ground for gambling. And especially if its not "Bostonian", it seems like a good niche to dig into for profits.

I would say absolutely include gambling in Fallout 4. I pretty much never spend much time with gambling minigames but I would enjoy it if we could incorporate them into a homebase that we have built in order to make some extra caps on games we host in the settlement. The more variety of activities the better, I think.

Maybe you can build one as part of your base.

Yes, since that should have been in FO3