For some mindbending reason, the developers either feared to be seen as endorsing smoking, so while you can have all sorts of addictive drugs in the Commonwealth, you cannot smoke. And only you cannot, as it seems like everyone else lights up all the time. I personally like to roleplay, and for certain types of characters, it would be fitting that they get all sorts of addictions and bad habits as they try to cope with how the world turned out and what they lost. It would be awesome if: - You could light up manually - As the addiction goes on, the character might do it on its own during dialogue - There would be a very minor boost, with diminishing returns, to something, and a very gradual health-, injury-, or radiation hazard. - Handshaking and blurry vision (instead of a headache, as that would be difficult to do) when detoxing