Considering the fact that, in some settings, magical creatures have naturally evolved...

Evolution doesn't create unstoppable species in a vacuum. It creates interdependent communities of different organisms. Non-magical organisms don't adapt to magic itself, they adapt to the resulting properties of magical creatures. Define those properties.

Introduce some sort of magic energy conservation law, or elemental transformations, and you're golden.

I'd assume that yes some creatures might be intelligent enough to use a innate form of magic.
>why wouldn't most creatures be out-competed by their magical counterparts?
Well magic can give advantage but it's not really absolute, like let's say there's a creature that can turn invisible, it can still be smelled or detected, same with your salamander, sure it can use fire and stuff, but it can also be spotted from far away because it emits light. There are even real life animal like snakes and bears that can detect heat signatures.

Your lore's dead, user. Just accept it and come join me in the adjacent graves labeled Soul and Hope.

I'm so sick of this

"If it's not a wizard going ooga booga and farting rainbows it's not magic!"

Whatever, maybe to you but it's far more interesting when the "magic" of the world is more ingrained then just doing a couple of spells and being done. The aversion to magic being defined as anything besides some kind of seemingly unknowable force that, conspicuously a few people know is very limiting.

Yet here we have a fucker who wants them in his fantasy setting.

>If that is the case, why wouldn't most creatures be out-competed by their magical counterparts?
>If there are magical apes that can think and talk, why are there still regular apes?
Because evolution is not a "winner-take-all" process.
There aren't even real winners, or "fittest" creatures.
Life lives, adapts, and uh, uh, uh, finds a way.

Also, don't forget the "people will hunt, kill, or otherwise destroy strange magical creatures they like or fear" aspect.
>One salamander panics and burns down a whole village, you bet your ass we hunt them to extinction. (except in those damn fire caves, let 'em have those blasted rocks)

>Would magic come from an organ?
Like a unicorn horn? Sure, sometimes, but not one universal magic organ, that's too gimicky.

>This entire post
You. I like you

I consider magic can be digested or processed through an organ and certain tissues, but it still needs an outside source. Dragons being the exception. Mages take their sweet time learning to manipulate ambient magic because it is against their very nature to be capable of doing so.

One common adaptation is certain creatures, like giants, being able to ignore or bend certain rules, up to a point, no reason to allow all and everything to happen.

Magic also speeds up the adaptation process.

Mundane and magical creatures coexist, because a species doesn't need to be all that adaptive and capable of surviving, it just needs to be good enough, like sloths and their weekly descent of the trees to crap one third of their body weight at once.

I like midichlorians as a sign of force potential. It's them BEING the Force that's dumb.
Tiny microscopic life forms that use force energy to sustain themselves and are attracted to concentrations of it are kind of neat. And it's a believable way of detecting space magic that doesn't science everything out of it.
Sort of like how you can use plant numbers to test water purity.

This

If you want to go down this road you need to take some 3 basic steps:

>1º-Define magic, fundamentally magic is energy on all levels, even mind manipulation is a form of energy manipulation, but you need to solve the details about power/composition/properties, this need to go in detail and be based in natural, observable and inmutable rules, use short statements here but very well thought.
>2º-Define how can magic be exploited, an organ is nothing more than a biological mechanism to achieve something, an organelle the same and so on, the most obvious way to say that magic can be exploited is the classsical imbalance, so what you actually exploit is a magic gradient somewhere, how such gradient is exploited its where you can go nuts writing, but always based on point 1.
3º-Now apply that to biology. To achieve this requires some bio knowledge but the main thing to understand in evolution is that when a solution emerges its random(therefore imperfect at first) and that population is what actually evolves, the individual only carries the question(is this small/major modification better?) that only the enviroment can answer.

Also take into consideration that magic needs some serious limits, if somehow your system allow supermutations that give superpowers to creatures it would be very difficult to have "higher" lifeforms since every hundred thousand years appears the nuke bacteria that creates a new extinction event, evolution on the fringes of carbon/oxygen/hydrogen biochemistry is quite hard and if everywhere becomes fringe territory...

With only that you should have more than enough to think about, hence, why most authors just go with the line "is magic" which works because a story is about human characters + conflict not about fantastical physics that are hard to come by, will probably be wrong or inconsistent at some point and offer very little reward for what they're worth.

They're still dumb.

If the force becomes something physical that means it can be measured, studied and used, so any mysticism involved in the subject is quickly blown away by simple pragmatism

The jedi stop being warrior monks to become energy capacitors(although that would make for an interesting biopunk star wars reinterpretation).

Nah, it's fine.

A bear can strike hard enough to murder every other land predator on earth in a matter of seconds because it will smash their bones to paste

So what if a fox is on fire or a boar can can shoot lightning from its tusks the bear will still murder both of them because it's still a quarter ton of anger and claws with skin that can shrug off pretty much everything they can throw at it.

What prevents the bear that develops the power to levitate and thereby attack from the skies from beating up all the regular bears and mating with all the she-bears and having flying cubs?

>in my setting incoming
In my setting, which is literally Dwarf Fortress with elemental wizards, magic is just another form of light that comes from the sun. Everything is more verdant and fertile because the plants get more energy from the sun for their buck. In places where there aren't as many plants on the surface to catch it, the magic penetrates into the earth and is caught by fungi in the caverns, powering that ecosystem. In other places the magical ozone layer is thinner, so more magic gets down there. Then you get things like giant bugs that die when they leave said areas and suchlike, things that only survive because of the magic that handwaves their strange traits.

I've already done this in exceptionally boring ways.

Every animal is a tiny bit magical, but the magic is usually so diluted it doesn't express itself unless you concentrate and purify their magical parts (component pouch stuff) or use selective breeding to magically enhance the creature or plant (for example, vineyards producing magical grapes for luminous wine or wealthy farmers growing gildengrain, a high-calorie variant of wheat.)

Every once in a while you get a magical creature out of the common stock, where the magic is powerful enough to express itself. These creatures never last long, since everyone wants to go on grand hunts for the White Stag or slay the Beast of Gevaudan.

>Become Magical Superpredator
>Only 1/50 creatures are magical enough for sustainability
>Have to hunt in a area so large, its almost pointless

This is the greatest Dangers of Magic Super predators.
What might be scary IRL, could turn out to be even worse.
I.E all terrain crocodiles, elemental swarm bugs

Magic versions of non predators tends to be okay, since they are only territorial.

>What prevents the bear that develops the power to levitate and thereby attack from the skies from beating up all the regular bears and mating with all the she-bears and having flying cubs?

Levitation is not a power they will acquire overnight, user.

I like it! may I steal it?

Go ahead, man! If you want to build a world with said ideas, I strongly recommend using an actual DF world as a starting point. Legends Viewer is your friend.

Gravity.