It's for mature audience only. Lot's of bloodshed, some nudity, topics of incest, rape, etc. Game of thrones is numerous story line in multiple perspective with a group of main characters along with really developed supporting characters. The writing is rather grand in tying all the rich story lines together for one main event. Everyone finds their own favorite character. The show is one of the most well written of this decade and can instill numerous emotions on a person.
It's a bloody great show. For mature adults.