If the player has the smoker trait, they will require having a regular cigarette, else they'll start to gain stress and eventually unhappiness. By having a smoke, they will receive a stress relief bonus (greater than without the trait).
This article or section may contain unconfirmed information about future development. It may not be entirely reliable.
It is speculated that in a future version, the player character may become addicted to cigarettes if used too often.
*This is now unlikely since the addition of the smoker trait in Build 35, along with cigarettes causing sickness if player does not have the trait*