Contributed by Southpaw Ben
An edict applying across the Roman empire requires that a third party must be present in any consultation involving a divination, and that one cannot inquire about anyone's death
My Take by Southpaw Ben
Divination in the ancient world often was used for making decisions, and was most commonly heard about when decisions were being made about whether or not to go to war. Often when the answer the inquiror was after was not given, they would treat it as the "Ask again later" magic 8 ball answer, and ask until they got the go ahead. Also the answers given would be vague, often allowing for all of the most likely outcomes, such as when a certain emperor asked if going to war with another kingdom would end in his success, the answer was something along the lines of "if you attack a great empire will fall", so he took it as a good omen and attacked, only to have his own empire fall. Also, for the times that a very definitive and clear answer was given, some historians have found proof that the example was added by historians hundreds of years later, and is never mentioned by primary sources.