Back in ancient times, before battles of yore, the Romans would prepare themselves to fight against legends and other beings. In order to cleanse themselves, they would take (for their time) the greatest dump in recorded history. If you take such a cleansing dump that you can accurately predict the moment of the next good fortune that you will experience, you have just taken a roman dump.
Revealing to others that you have taken a roman dump will instantly improve your charisma score and open up more favorable dialogue choices.
Man 1: You have been in the bathroom all day! Did you fall in?
Man 2: Nahh..I just took a roman dump.