There may come a time when your players (or you, if you are a player, or even if you aren't) decide that you don't want the game to begin with social outcasts and advance into powerful lords. This time may come, depending on your group, instantly or, like mine, some five years down the road. The question embodied by this tendency can be stated simply and easily: 1 - "Can we begin play tied into the social order?" if the answer is yes, this leads to a question in two parts— "How can we accomplish this (a) in terms of roleplaying and player-load and (b) in terms of rules?"
The question is divisible, like all questions, into a number of parts.
A) What does it mean to be integrated into the medieval social order?
To be integrated into a medieval social order it is necessary to be given an occupation (the assumed occupations of most D&D characters being simply peasant, merchant, or outlaw), to be trained to perform that occupation, and then to assume its mantle. Additionally, one must be tied into social responsibilities surrounding one's station or occupation.
Concrete examples that are normally not available in AD&D include:
Knighthood—normally a reward for valor (and level gain) in D&D, being a knight was the normal course of affairs for nobility of all kinds. This, really, is a subset of the noble class.
Artisanship—artisans have a master, they study with their master, and then they open shops of their own. They generally belong to a craft-guild (if such things have formed yet) and have civic obligations wherever they open shop (universally an urban environment).
Membership in a Wizards Clave–something that can happen at higher levels normally, it is more than possible for an apprentice to begin the game as a member of one of these organizations.
Priests as well can begin play as integrated into the structure of their temples rather than the semi-autonomous units wandering the countryside.
B) How may we give player characters occupations?
The answer to this is fairly easy: through kits. I've already posted a few kits of knightly orders on the blog, which have worked fairly well ingame. Thus, it is not difficult to mold player characters into knights or artisans given that you include certain aspects to give the kit verisimilitude.
C) How may we deal with the vast amount of knowledge players must have to be "integrated" socially?
Our answers here are twofold and simple: 1) wait until the players have played in your campaign setting for a while or 2) give them a great deal of setting information when they want to play a character who doesn't start as some kind of social outcast.
Corollary: This may be the most important part, and it has to do with servitude. Everyone in medieval society had a mixture of obligations. The reason we generally make characters who are social outcasts is because it can be a pain to model those obligations. There is, however, some benefit to be gleaned from working to properly craft medieval obligations and lines of force, which is the only reason to pursue them.
The primary form of obligation comes in the form of a social obligation, which all members of all classes will feel if they are part of good society. This encompasses travel restrictions (I own a shop, I serve this lord) as well as obligations of obedience (I must go and fight because my lord is going to war). The second form of obligation is a personal or servile obligation—I am a squire, I am an apprentice, etc.
The second form of obligation has been presented in many different ways by many different games, but usually is left to the vaguery of the DM in AD&D. While Space 1889 cleverly makes the masters of servant characters into brain-dead morons that the servants can manipulate (with hilarious results), it is possible to grant a character a master, intrusive patron, or other such figure without making them ciphers for the will of the character/player.
This was really meant to be a post on playing in servile positions and then the kinds of servants one could expect to have, especially as a noble or a knight, but I think I'll save that for tomorrow or another day. I'm in Florence right now, so weird things are coming to me at odd hours.