In a game play stream i watched last night, a few months back, rocket was talking about what people think about him adding smoking and cigarettes in DayZ mainly for roleplay. I believe the streamers name was sacriel42 or something and vids up on youtube.
Edit: Video with Rocket talking about adding smoking to DayZ:
Starts at 2:20
Some suggestions that came up in the stream were that smoking could reduce shock damage (seems like players can get into shock after being hit badly and when they do they can't bandage and reload for a few seconds - i didn't know this or if its even implemented yet) anyway effectively calming the player. A negative effect would be too slightly decrease stamina while smoking.
Anyway I was thinking about this and though it would be cool to use cigarettes as a type of currency in the apocalypse. Players could find packets of smokes with varying amounts of cigarettes in them in the world and they could trade them for food and guns etc. Well at least in a role playing server.
For example, a player could trade 100 cigarettes for an SKS at a vendor.
I know this will never happen in dayzsa vanilla, but wouldn't it be cool if players could buy Food/Water/Ammo etc off NPC vendors using cigarettes as a form of currency?