Ser Waymar Royce was the youngest son of an ancient house with too many heirs. (1 Prologue.14)
Like a good pseudo-medieval society, the noble houses of the Seven Kingdoms practice primogeniture, which means that the first-born son gets all the goodies (land, title, ancestral sword, Pokemon collection). Both in Westeros and in actual history, primogeniture was super important; it meant that a lot of people had to go make their own way in the world by fighting for others.
Even at seven, Bran understood what his brother had done. The count had come right only because Jon had omitted himself. He had included the girls, included even Rickon, the baby, but not the bastard who bore the surname Snow, the name that custom decreed be given to all those in the north unlucky enough to be born with no name of their own. (2 Bran 1.70)
We know that each of the Seven Kingdoms has a customary last name for illegitimate children: Snow in the north, Stone in the Vale, Flowers in Highgarden, Rivers in the Riverlands, etc. (35 Catelyn 6.77). But how does society treat these illegitimate children?
Arya thought that Myrcella's stitches looked a little crooked too, but you would never know it from the way Septa Mordane was cooing. (8 Arya 1.3)
Royal people can get away with a lot, Arya learns. And that lesson starts in her own home, when Princess Myrcella gets a little special treatment. But can we blame Septa Mordane for trying to be nice to the royal family? They have their own executioner, after all.
"None of these others have ever had a master-at-arms until Ser Alliser. Their fathers were farmers and wagonmen and poachers, smiths and miners and oars on a trading galley. What they know of fighting they learned between decks, in the alleys of Oldtown and Lannisport, in wayside brothels and taverns on the kingsroad." (20 Jon 3.66)
Donal Noye reminds Job that he's had a privileged social position in the world. Sure, he's an illegitimate child, but at least he's not common.
Her handmaid Irri and the young archers of her <em>khas</em> were fluid as centaurs, but Viserys still struggled with the short stirrups and the flat saddle. Her brother was miserable out here. (24 Daenerys 3.6)
Of course, society isn't the same everywhere you go in this book. Our primary example is how badly Viserys misunderstands the customs of the Dothraki. Not only can he not ride, he also thinks riding in a cart is an honor (when it's really an insult). Oops.
While the commons began their walk home, talking of the day's jousts and the matches to come on the morrow, the court moved to the riverside to begin the feast. (30 Sansa 2.22)
Nobility sure has it easy: after the tournament, the commoners all go home, while the nobles get ready for a feast. (And who made that feast? Yep, the commoners.)
Dany gave a wordless cry of terror. She knew what a drawn sword meant here, even if her brother did not. (47 Daenerys 5.70)
In Vaes Dothrak, you're not supposed to spill any blood. That means no swords. But Viserys – stupid, stupid Viserys – never bothered to find out what customs were like in this society. This is a great example both of culture clash and just plain ignorance.
"To be a knight, you must stand your vigil in a sept, and be anointed with the seven oils to consecrate your vows. In the north, only a few of the great houses worship the Seven. The rest honor the old gods, and name no knights... but those lords and their sons and sworn swords are no less fierce or loyal or honorable. A man's worth is not marked by a ser before his name." (54 Bran 6.12)
Even geography is important in determining societal values. The north is quite different from the south in terms of both customs and religion. Then again, they both have some rockin' soldiers.
That was the trouble with the clans; they had an absurd notion that every man's voice should be heard in council, so they argued about everything, endlessly. (57 Tyrion 7.9)
Tyrion finds the Mountain Clans strange: they practice democracy, for crying out loud. Who does that, anyway?
"When I was a young boy, before I was cut, I traveled with a troupe of mummers through the Free Cities. They taught me that each man has a role to play, in life as well as mummery. So it is at court. The King's Justice must be fearsome, the master of coin must be frugal, the Lord Commander of the Kingsguard must be valiant... and the master of whisperers must be sly and obsequious and without scruple. A courageous informer would be as useless as a cowardly knight." (59 Eddard 15.39)
Here, Varys explains to Eddard why he can't be a heroic spy. It actually makes some sense (though we hate to admit it). But what about his larger claim? Do you agree that everyone has a role to play? Do people in this book get to choose their roles?