Post by The Dark Herald on Oct 20, 2009 16:35:30 GMT -5
This is the only printed 3.5 source material I know of that allows for an estimation of a half-dragons age.
Until a Dragon Disciple becomes 10th level an gains the half-dragon template, they have the normal lifespan for their race. Once they gain the half dragon template, that would change according to this rather vague summary. A RDD is essentially just a specific brand of DD, so there would be no difference in the RDD and DD lifespan, both would use the lifespan of the base race until reaching 10th level and gaining the half-dragon template.
This source implies that they gain 'much more time than most' and 'share in the heritage of the shorter lived races'. From that we can guess that a half-dragon half human would live much longer than a human, but not as long as a dragon so maybe 200-300 years? It's really open to interpretation. Also according to it, a half elf half dragon would live as long or longer than an Ancient Wyrm.