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When a dragon in polymorphed form mates with another creature, the union sometimes produces half-dragon offspring. A creature might also transform into a half-dragon as a result of a mad wizard's spell or a ritual bath in dragon's blood. In all these cases, the result is a creature that combines the essence of a dragon with the form of its original race. Regardless of their origins, all half-dragons have similar features and appearance, gaining special senses, resistance to destructive energy, and a breath weapon.
Draconic Nature. Half-dragons are incapable of having natural born offspring. Those that wish to propagate must find other ways to do so, almost always involving magic. By way of compensation, half-dragons are blessed with long life. Barring unforeseen misfortune, a typical half-dragon's life expectancy is twice that of its nondraconic line, so that a half-dragon human might live more than a century and a half.
Half-dragons inherit personality traits common to their draconic heritage, so that half-gold dragons are often shy and secretive, while half-copper dragons are impish and playful. Half-green dragons are deceitful, while half-white dragons are often dim-witted brutes. These traits are tempered by a half-dragon's other lineage, but greed, arrogance, and paranoia are qualities that even good-aligned half-dragons often possess.
Resistances. The half-dragon gains resistance to a type of damage based on its color.
Languages The half-dragon speaks Draconic in addition to any other languages it knows.
New Action: Breath Weapon. The half-dragon has the breath weapon of its dragon half. The half-dragon's size determines how this action functions.