1

This question already has an answer here:

Thorin was successful in causing Smaug a great deal of agony, but the molten gold was ineffective beyond that. Smaug is obviously capable of dishing out extreme temperature, so why did Thorin believe that he could be killed by it?

marked as duplicate by Shevliaskovic, user8719, BBlake, Andres F., FuzzyBoots Jan 2 '15 at 13:56

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

0

This isn't in the books and no explanation is given in the movies. The only answer, I'm afraid, is "Jackson - 'nuff said".

A speculative explanation may be that perhaps Thorin thought he could drown Smaug rather than burn him. Obviously the heat of the dragon meant that he couldn't drown him in water (which would just evaporate), but molten gold should be suficient if you want to drown a dragon. But that's just speculation.

Not the answer you're looking for? Browse other questions tagged or ask your own question.