Shaiya is a great tool for teaching what modern Feudalism.
There are 2 classes of people: The Nobles and the Peasants.
The Nobles are the rich people that control every aspect of this game. They can make people's lives pleasant, if you submit to their authority, or they can make your lives miserable.
In PvP they one shot kill their enemies, and allow their obedient subjects to leach from them.
In PvE they use their generosity to bless those that subject themselves to them. For all others they crush through oppressive economics. Then there are the guilds that use a form of high taxation (they take your time in mandatory activity attendance) in the promise of a chance to better themselves.
The Peasants are the ones that do not have the wealth to play this game. They try hard, very hard to make a better life for themselves. They create great relationships with others. Establish great friendships. They work at helping one another. They try really hard to move up the ranks in the society. They are the majority of the player base, but since they don't have the wealth of the Nobles, they will always be subjected to the wills of the Nobles.
Many in the Peasant class are very happy with this game as long as they don't try to move into the Noble ranks. When they desire to move into the Noble ranks, then great pain and frustration will come into their lives until either the attain the real world wealth to play, or submit entirely to the authority of the Nobles.
This game is not a faction war - light versus dark, but more of a class war - rich versus poor.
As you play this game you will learn who the Nobles are, they are obvious in the game and in the forums.
If you are not in the Noble class before you start the game, then you will be in the Peasant class for your entire life in this game.
I am not saying the being a Peasant is a bad thing, it is just as long as you realize your class and don't have desires to change your class, then you will have a wonderful time in this game.
Feudalism still exists in the 21st century