World Without Fire

There's a persistent myth about the indigenous people of Tasmania, to the effect that their isolation from the Australian mainland caused their technology to deteriorate, eventually to the point where they were unable to produce fire. Early colonial accounts describe Tasmanians carrying 'fire sticks' with them, using them to light campfires instead of producing fire on-site. 

Turns out, they knew how to make fire just fine (as the linked article above points out, some of those same colonial accounts contained extensive interviews describing Tasmanian methods of fire production), it was just inconvenient. Tasmania is cold and damp, with average summer highs around 70 Fahrenheit, and in the colder and wetter seasons it's a much better use of time and energy to link fires rather than start each one by hand. 

But this just now got me thinking about a world where this wasn't the case. A world in which humans could not produce fire on their own, as before Prometheus stole it from the gods.

Consider your usual fantasy world: ancient empire of high magic, great catastrophe, contemporary people picking their way across the ruins of a society greater and more terrible than themselves, all that good stuff. 

Now, consider that your great catastrophe resulted in the elimination of mortal fire. Whatever fires exist at that moment must be protected at great cost. Lighting new ones is only possible only by taking an existing fire, setting something alight, and journeying with it. Source fires would be like pagan gods, jealously protected within temples and fed with fuel and given offerings that please them. You might find a fire honored at the heart of a powerful city state, tended by many priests, or kept by a small cult in an isolated cave. 

Let us take it one step further and suppose that not all fires are alike. In fact, they're sentient, and some are sapient. Some dumb, some smart, some destructive, some mild, some powerful and some weak, with varying temperatures and natures. 

Perhaps they have varying aptitudes as well. One fire might be suited to the hearth, possessing a gentle and far-reaching warmth. Another is friendly and variable, suited to cooking, or another might possess the intensity and intelligence needed to forge metals. A proper fire is almost certainly necessary to do things like create potions or magic items. 

Just another step further: just as humans can no longer create their own fires, neither can fires expand without limit anymore. A great and old fire can split itself many times, enough to light the hearths of an entire city, but a young fire, or else one that has been starved or otherwise injured, can only light a handful of child fires. It can no more start a forest fire than a person could physically stretch their body over the same area. 

This results in a world in which fire is rare, precious, and a constant concern. Settlements in our world are built around water, but in this world they would also be constrained by the presence of old and friendly fires. Sources of natural or magical fire would also become incredibly important. Why does that drakencult have so much influence? Because their god can make fires wherever it wants! Why do people live on the slopes of an active volcano? Beside the fertile soil, because it's an endless source of powerful, albeit violent and demanding, flames! Facing an extinguished source fire, communities will devote themselves with new fervor to a god who can grant them a new, warm flame, or they might turn to infernal forces which supply them with a cold fire that burns anything other than silver. 

As you might expect, this requires some trimming of standard inventory and character options. No fire spells! No flametongues! Take flint+steel off the equipment list, and torches/lamps are probably far more expensive. Summer is the go-to adventuring season, and anyplace cold and dark is bound to be filled with treasures nobody has looted yet. 

Some other considerations: fires can die by starving, suffocating, drowning, etc, but they can also go mad. An unleashed flame will spread rapidly and violently, and destroy itself in the process. Otherwise, a child fire cannot set anything alight by itself: it can deal damage and create heat, but not ignite. Some fires need alternative fuels, or need certain things for their magical properties to shine through. Some just like certain offerings, and make their cooperation contingent on proper obeisance. An exotic fire might burn stone, water, precious metals, etc. 

Sources of magical fire with varying properties include: volcanoes, burning gas pits, dragons, fallen meteors, the grace of a particular god, a contract with a devil, capturing or killing a solar angel, and more!

In such a world, it would also be necessary to explore new sources of both light and heat: bioluminescence and other heat-producing chemical reactions could be part of standard kit. 

Some adventure hooks for this kind of setting:

• Your wizard is getting up in levels and wants to start making their own potions and magic items. They need a powerful and exotic flame for this purpose, so venture out into the world to locate the viridian flame that burns in the gaseous heart of a poison swamp!
• The source flame has been stolen from the temple in the dead of knight by a treacherous priest! If the source flame goes out, the entire city will be endangered and the temple's influence will blow away like dust in the wind. Of course, even if you recover it, there's no reason to just give it back right away...
• A young dragon has been spotted hunting in the nearby mountains where no dragon has been known to dwell before. If you can capture and subdue it now while it is still young, you can use its destructive and rampant flame as the basis of a powerful military organization, or try to tame it into a magical forge-fire. 
• A child of fate has been born nearby, in whose body dwells a magical flame. They can cast fire magic and have great advantages when dealing with other magical fires! Keep the child safe, or try to capture them and take this power for yourselves...