“When person A farts, it is person A’s duty to call “safety” before person B calls “doorknob.”  If person B calls “doorknob,” person B can punch person A for his sinful act of farting in public.”

Duke learned this game from his friends sometime in high school.  It became a very popular game among the boys at his high school.  Boys tend to fart a lot, so this game provides them with a punishment for farting in public.
Since Duke and his friends have a habit of farting numerous times when they’re with each other, they play this game a lot.  Whenever someone farts, it’s an immediate reaction to hear the word “safety” or “doorknob” following the fart.  Duke claims that he plays this game to get a cheap-shot off of a friend’s fart.  It also provides them with entertainment as they laugh about farts and punching each other.
Even though Duke thinks that this game is stupid, he still does it.  It has become something that all of his friends know.  This game is their way of reacting to farts.  They think that there has to be a consequence for farting in public, so a punch suffices as a punishment.
I think that, in a way, this game is good for boys.  It forces them to take the blame for farting in public.  Farting in public is very disgusting and immature.  Boys need to learn to keep their gas in until the appropriate time.  With this game, maybe boys will avoid farting whenever they choose to.  However, I don’t think that boys should have a game to prevent them from farting in public.  They should know not to do it.  The fact that they need a game proves that some boys are just immature and rude.