A Gygaxian Manipulus Florum

While I believe that each DM and gaming group are authorities unto themselves (I lean towards conciliarism in my approach to gaming), I present a handful of gygaxian flowers that guide my play:

1.
A few brief words are necessary to insure that the reader has actually obtained a game form which he or she desires. Of the two approaches to hobby games today, once is best described as the realism-simulation school and the other as the game school. AD&D is assuredly an adherent of the latter school. It does not stress any realism (in the author's opinion an absurd effort at best considering the topic!). It does little to attempt to simulate anything either. Advanced Dungeons & Dragons is first and foremost a game for the fun and enjoyment of those who seek to use imagination and creativity. [DMG p. 9--bold and italics in original]

2.
Skilled players make a point of knowing what they are doing i.e. they have an objective. They co-operate--particularly at low levels or at higher ones when they must face some particularly stiff challenge--in order to gain their ends. Superior players will not fight everything they meet, for they realize that wit is as good a weapon as the sword or the spell. When weakened by wounds or nearly out of spells and vital equipment, a clever party will seek to leave the dungeons in order to rearm themselves. (He who runs away lives to fight another day) [PHB p. 8]

3.
As the creator of a milieu, you will have to spend a considerable amount of time developing the population and distribution of monsters--in dungeon and wilderness and in urban areas as well. It is highly recommended that you develop an overall scheme for both population and habitation. This is not to say that a random mixture of monsters cannot be used, simply selecting whatever creatures are at hand from the tables of monsters shown by level of their relative challenge. The latter method provides a rather fun type of campaign with a "Disneyland" atmosphere, but long range play becomes difficult, for the whole lacks rhyme and reason, so it becomes for the DM to extrapolate new scenarios from it, let alone build upon it. Therefore, it is better to use random population techniques only in certain areas, and even then to do so with reason. [DMG p. 91 italics in the original]

4.
Most DMs love communication and negotiations, for this allows them to assume an active role in actual play. Your referee will assume the persona proper to the creature your party is dealing with--be it shy or hostile, stupid, greedy, helpful, misinformed, or whatever... ...Negotiation usually gives you a chance to get on with the earning process, or live to come back and fight another day. Always be wary and use your wits, look at all facets and situations and use your best judgment accordingly, in many cases a payment, bribe, toll, share or ransom fee will enable success or survival, and negotiation is a useful tool to the expert adventurer. [PHB p. 104]

5.
Each individual campaign has its own distinct properties and "flavor." A good Dungeon Master will most certainly make each game a surpassing challenge for his or her players. Treasures and experience gained must be taken at great risk or by means of utmost cleverness only. If the game is not challenging, if advancement is too speedy, this it becomes staid and boring. Conversely, a game can be too deadly, and become just as boring, for who enjoys endlessly developing new characters to march off into oblivion in a single night of dungeon adventuring? [PHB pp. 7-8]

6.
As a realistic simulation of things from the realm of make-believe, or even as a reflection of medieval or ancient warfare or culture or society, it [AD&D] can be deemed only a dismal failure. Readers who seek the latter must search elsewhere. Those who desire to create and populate imaginary worlds with larger-than-life heroes and villains, who seek relaxation with a fascinating game, and who generally believe games should be fun, not work, will hopefully find this system to their taste. [DMG p. 9]