Why are Dragons "Always X" alignment?

Question

As per this question and the answers provided therein, Dragons are of the "always X" alignment. Which means...

Always: The creature is born with the indicated alignment. The creature may have a hereditary predisposition to the alignment or come from a plane that predetermines it. It is possible for individuals to change alignment, but such individuals are either unique or rare exceptions.

A description that is usually reserved for such races as Demons, or positive/negative energy aligned creatures... and yet, is also applied to dragons.

This strikes me as somewhat odd, given that dragons are intelligent creatures capable of making decisions of their own, not directly tied to any particular good/bad plane of energy.

What then is the in-canon reason for Dragons being "Always X" alignment?

Answer 1

Much of this has to do with the history of dragons, and the fact that D&D draws significant content from existing cultures. Primarily, dragons were representations of the balancing forces in nature in many cultures. In Europe, they tended to be less so, though they were still symbols of longevity:

Dragons are often held to have major spiritual significance in various religions and cultures around the world. In many Asian cultures dragons were... revered as representative of the primal forces of nature, religion and the universe. They are associated with wisdom—often said to be wiser than humans—and longevity. -- Comparative mythology of dragons (emph. mine)

Fundamental forces of nature are, by strict lore, either slow to change or do not change at all. This, I believe, is very likely to be the original source of the polarizing nature of dragons and their alignments. In D&D, battles between dragons are long, deep, and complex, which is indicative of this spiritual form of dragons. To address why many dragons are evil in D&D:

European dragons are usually depicted as malevolent, though there are exceptions (such as Y Ddraig Goch, the Red Dragon of Wales). -- European dragons

The canonical form of dragon which appears in D&D is a form of the classic European dragon; wings, tail, claws, legs, and lives in mountains or underground. However, Gygax and the D&D team are well-known for drawing ideas from multiple sources, so it is very likely that his descriptions incorporated the magic of many Asian cultures, representing dragons as fundamental forces of nature, which are slow to change and last for inconceivable spans of time.

In short, the dragons we see in D&D are a combination of the European-style bodies and the Asian-style souls and identities. Though both traditions have been somewhat corrupted from their original form, the intent is the same: the dragon is intelligent, long-lasting, and representative of a fundamental force, and is therefore unlikely to change. Or, at most, will change slowly and infrequently.

Answer 2

You've got the wrong end of the stick. You say it's "a description that is usually reserved for such races as Demons..." and then you wonder why dragons get this treatment too. Rather than wondering, that is your answer: dragons are something much more like demons – in that they have an immutable nature – than like beasts or (demi)humans.

As for "Why?" the answer is "because." Gygax made them that way in the setting implied by the 1st edition AD&D Monster Manual.

This might conflict with your own conception of dragons in your setting (assuming you're the GM), and that's OK: if dragons are more nurture than nature in your world, you're free to ignore the alignment restriction. Otherwise, considering it a data point telling you something about dragons in that setting.

Answer 3

A dragon is strongly instinctive, and too powerful to be forced to reexamine its life and decisions. Since no one is strong enough to make them reconsider, they continue as internally guided. (Their very high INT, WIS, and CHA make them difficult to persuade by any means--everyone else is lesser, with easily dismantled arguments.)

Answer 4

As per Page 305, Monster Manual always doesn't mean always:

Always: The creature is born with the indicated alignment. The creature may have a hereditary predisposition to the alignment or come from a plane that predetermines it. It is possible for individuals to change alignment, but such individuals are either unique or rare exceptions.

So the question ought to be why do most dragons stick with their original alignment given the lack of planar predetermination.

The answer is part of the quote "hereditary predisposition" is the closest thing to genes you'll find in an rpg. It's in their genes.

At this point the question becomes why is it in their genes? This could mean why did the game designers create genetic predispositions regarding alignment? Or why would it be so in-game?

Let's start with a definition:

Wikipedia on "Dragon (Dungeons & Dragons)" (emphasis added)

In D&D, dragons are depicted as any of various species of large, intelligent, magical, reptilian beasts, each typically defined by a combination of their demeanor and either the color of their scales or their elemental affinity.

• Wikipedia referenced the Draconomicon (Wizards of the Coast, 2003) by Collins, Andy, Skip Williams, and James Wyatt - which I haven't read myself.

So Dragons are designed to be somewhat like reptiles. According to neuroscience and evolutionary biology the reptilian brain is very old and primal, explaining why reptiles are largely instinct driven creatures. Now dragons are also described as intelligent, which has many meanings in psychology.

According to the D&D System Reference Document it means

Intelligence determines how well your character learns and reasons.

Mechanically this covers number of languages spoken, skill points per level and modifiers to the following skill checks: Appraise, Craft, Decipher Script, Disable Device, Forgery, Knowledge, Search, and Spellcraft.

None of these demand existence of free choice, as a really "smart" robot could do any of these things. If dragons are genetically predisposed the same way a computer is logically predetermined, reasoning logically might convince a dragon to change his behavior, but never underestimate a smart mind's capability to rationalize the status quot. (See social psychology research on cognitive dissonance)

So Dragons are born with a strong drive to behave in certain ways, and are equipped with the mental capacities to rationalize to maintain that way. However, some experience the exceptional circumstances necessary to drive them to change.

I don't know the average age of dragons, but adults are about a century old and the older they get the more powerful they get, and more power makes it less likely to encounter a situation in which one's tools are no longer enough, thus normally they lack a necessity for change.