Dragons and their ability to breathe fire upon their foes are a common occurence in fantasy. Today, I’ll look at the various ways this can be approached with their strengths and weaknesses.
Before I go to the specifics, the level of detail an author gives to the biomechanics of dragonfire can differ from none to almost scientific level.
Should dragons exist, it’s very likely their fiery breath would be, first and foremost, a defense mechanism. Animals are accustomed to eating their food raw so it’s unlikely it would have the purpose of cooking their meal – not to mention the sheer power could leave nothing but ash.
It’s only when dragons are utilized as a weapon of war when their fiery breath becomes a powerful weapon. How exactly their fire works then affects how powerful a dragon is, with or without a rider.
Also, a fire-breathing dragon looks bad-ass on a book cover.
Now, on to the fictional science.
Fully magical breath is the simplest way to approach this ability. The major advantage is that, by being magic, it faces minimal amount of limitations. And because one can define magic as they want to (though there are dangers to that as well), this approach can be shaped to anything and require minimal explanation, possibly making it the easiest to write. This is also the biggest disadvantage: powerful abilities with minimal drawbacks and counters are prone to being boring.
Now, I’m moving on to variants that are based on complex fictional biology. Stories of this kind require showing at least some level of fictional biology and thus require at least some understanding of biology to avoid potential inconsistencies.
In most cases, bio-chemical breath is created by one or two compounds (usually liquid). How this translates to fire differs: either the final liquid (whether from one or two compounds) is highly flammable and ignites on contact with air (oxygen), the dragon sets it ablaze intentionally (such as creating a spark by grinding their teeth), or individual compounds are reactive together and burst into flames on contact.
Each compound then needs to come from somewhere – the approach I’ve seen the most is a gland creating those compounds and either storing it in a bladder-like organ or directly spraying it out. The details then limit how much fire a dragon is able to use (as creating those chemicals is likely bound to take time).
Apart from that, the position of the gland/bladder is then a potential weakness – if it’s just below the skin, then stabbing the dragon between the scales and rupturing the bladder might be a way to blow the dragon apart (if the chemical is reactive enough). Or, in an opposite case, causing the flammable compound to leak can resemble in something akin to acid burns should a rider be hit.
As for the range (or reach), wind is likely to be a major factor in flight, as well as the momentum. Thus, a dragon breathing directly ahead would likely burn its reader (or even itself) as the momentum of the flight would sent them right into their own fire – which is the main reason why the fire is used against ground troops more than against another dragon in aerial combat (at which point claws come to play).
Defense against the fire
While the main topic of my post is expended, there’s one thing to mention: how could one defend themselves from a dragon’s fire.
And the answer is: poorly. A conventional ground troop stands pretty much no chance – the only way to survive would be avoiding the fire (mean: run away before the breath comes down on you), some specific magical ways (such as a shaman affecting the wind), or magical shield – though the latter two methods might not be enough if the fire’s heat still reaches you. There’s a possibility that an author would come up with a defense – especially if dragonfire was a frequent threat and the people would have to keep said danger in mind.
I’ll wrap it up here. Feel free to share your thoughts on this topic.