Why did Green Dragons change to acid in 3e and then back to poison gas in 4e without the chlorine? Would the universe have exploded if 4e went sonic?
No idea. For my personal rework of dragons, we'd ditch bronze and brass (which are alloys, even if they can sometimes appear in nature), and instead have two other metals: cobalt and iron. I gave iron dragons the lightning breath (because magnets/electricity) and made cobalt dragons thunder (aka 4e's version of sonic).
What's the point of metallic dragons? Why aren't silver ones giant mirrors that shoot lasers (as per
@Vaalingrade 's brilliant suggestion)?
In my unwritten dragon-centric cosmology, the "point" was that both Metallic and
Prismatic dragons were things of beauty and purity: metals or
gemstones. But when Tiamat fell in the ancient days--she had been meant to be Monarch (dragons are all genders and no gender; they choose what aspects they wish to manifest, and Tiamat identifies as a mother), but instead became Corrupter. Where once she had glistening scales in seven colors (the extant five + yellow and purple), now she has just five heads. What happened to her Topaz and Amethyst children is not known, but they have not been seen since her fall. Her mate, Bahamut, now struggles to keep creation in order with her absence; Bahamut was
Counselor, not Monarch, and filling Tiamat's role has left him stretched thin. (Not to mention, his very essence is now at war with itself: he was
designed to be Tiamat's mate, just as she was designed to be his, yet he was also designed to fight exactly this kind of corruption. It is the great tragedy of existence that they are driven so far apart.)
Because the above requires there be seven Prismatic dragons, there were also seven Metallic dragons. The new types are wolfram (aka tungsten), which would be depicted as faintly greenish, and a fictional metal,
tyrium, named after tyrian purple. Haven't decided what their breath weapons would be. That's a neat idea with the lasers, I'll have to think on that. Perhaps a trick older, larger-winged silvers can pull on unsuspecting targets.
Is the Quasar Dragon still greatest of them all?
Never heard of it, so probably not.
How about the new (old) ones in Fizban?
Haven't read it, so I couldn't say. I personally preferred 4e's Catastrophic dragons for things that are a bit more eldritch than your usual dragon.
Were the orange, purple, and !?!? dragons ever worth looking at back in Dragon Magazine (iirc?)?
Some of the weirder off-brand dragons were interesting. I liked...I think it was "tome" dragons? They were big on metamagic and were even nerdier than golds.
What is your biggest concern about Dragons?
That they are simultaneously over-used and under-used.
That is, it's easy to trivialize dragons as opponents by just throwing them in wherever you want them to be. I think that's a shame, because a well-run dragon antagonist (or even ally!) can be really interesting and exciting. Dragons are sort of inherently a creature about
power, that's what they've meant in basically every culture ever (because nearly every culture has some kind of serpentine mythological figure or entity that gets identified as "a dragon.") That gives them an allure, a symbolism, a significance. Allowing that to get diluted into Monster Of The Week territory is just sad.
On the flipside, however, there are some who...kinda act like because dragons have this allure, they shouldn't EVER show up ANYWHERE unless it's super duper ultra important. They shut out the possibility of letting draconic flair seep into other things in ANY way. That's a big part of what drives many dragonborn critics, from what I can tell; they see the race as
tawdry, more or less, as sort of trying to "cheat" into inherent awesome just by being part-dragons. I find that a pretty jaundiced take, and actually really
love seeing such draconic motifs worked into worlds and lore.