I’ve posted before about my parthenogenic, mutagenic dragons.
Whence different colors of dragons? Why would a proud red sire (mater?) a sniveling white whelp, and allow the child to survive to her primacy?
The quick answer is that they wouldn’t. Red dragons nest in temperate zones, and white dragons in arctic ones, a-doy. But they surely should be able to, what with the mutation blood and the asexual reproduction.
Nature vs Nurture
Dragons hoard. What if that’s an incubation strategy?
A dragons egg is infused with the feng shui of the parent’s hoard. The metallics are actually not significantly benefitted by this, since the outcome is affected only by the single most valuable object in the hoard; the rest of the hoard is an attempt to influence the egg towards that object, or to buffer sub-hoards (and thus eggs) from each other.
Rubies yield reds, emeralds greens, sapphires blues; onyxes black, opals white. That gets us a theme and a dragon trying for that theme; we’ll say diamonds are more random, producing the parent’s type much of the time, and a random type the rest of the time.
We’re going to fiddle with the completely forgettable brass and bronze dragons: brass is currently a desert-based illusionist with a fire and sleep breath, bronze coastal with lightning and repulsion; copper has acid and slow, hilltops and terrain effects.
They’re just not useful to me: they’re not cool metals, and they’re not memorable effects. Gold and silver are fine, so far as they go, but these three?
Instead, let’s talk gold, silver, copper, iron and lead.
Iron dragons have fire and sickening breath (like iron golems: this breath deals no damage but does impose the poisoned condition) with the stats of bronzes but the lair and lair effects of brass.
Lead dragons have acid and slow, the stats of brass and the lair and lair effects of bronze (lead/acid battery and burdens the victim).
Copper has lightning and repulsion and it’s own lair and lair effects (conductor and electromagnetism).
This gets us moving again: we have metallics and they’re interesting; we have a loosey-goosey fluff justification for certain types of hoard.
I’ve mentioned before that a dragon’s size is foretold by her hatching; that an ancient wyrm is rare because most wyrms just can’t attain that size, they lack the genetics. What if the gp value of the hoard determined child size, or even personal size?
That is, a dragon needs one gp per XP value to attain large size. They sicken and wither if denied their haul. Or their eggs hatch as squibs, unable to grow to the scale of their dams.
Something like that.