How Magic appear?

She cried as the rain poured upon the destroyed city. She laughed as the rain began to burn it all away.

It began as simple weaving to remember stories, and then the stories began to come alive. People began to wonder why.

1. Since all magic is innate to all living beings then all of them are using a little of it instinctively. Somewhere some dude thought: " Hey if I wonder how much more I can heat this shit up by waving my hand".
A few hours later the first firebolt was thrown.

A long history of ritual sacrifice and offerings to access magic until people began to discover alternative methods.

"Abod ber" she said alone
"Abod ber" they began to join in
"Abod ber" the earth began to shake
"Abod ber" the first fortress was made.

>A spiteful god wrecks "race"
>Thinking "race" destroyed said god goes back to the heavens to wreck their creator
>Creator gets his shit kicked
>Dying breath gives the "race" he created ability to cheat death.

The cheat was necromancy. And with it that "race" drowned the god that tried to kill them in fucking skellingtons and uber liches.

Humans were without magic in primordial stone ages, but were smiled upon by the One Supreme, gifted with long lifetimes and the potential for immense stamina and strength. Myth holds that men and giants were one race in these ancient times.

Nine mortals grew so great in power that no gifts granted to them by the One Supreme could sate them, or surpass that which they could take by force. More than Her immortality, they grew to envy the magic that belonged to the One Supreme and Her angels alone. The Nine climbed the Sky Chain to raid heaven, and slew the One Supreme.

The shattered body of the One Supreme fell from heaven, and now Her golden, castle-like bones lie beneath the mountains and protrude into the Deep below the world. Her blood watered the earth, and it grew wild, fey places where the forest still holds divine power to distort the world.

The world now lives under a curse. The nine, who drank of the blood of the One Supreme, returned to the earth wielding magic beyond their power, that shattered their minds. Some gibbered in tongues, each rambling an incantation; their words have passed into epics and songs, and passed by bards for generations. Others recorded their twisted thoughts in dozens of tomes, now pored over by scholars who decrypt the madness. One of the nine, now called Arkynd, the Redeemed, immolated her living body and soul, to cleanse herself of her grave sin; today, Pyromancers light their lanterns from her eternal pyre, and learn to commune with the will of Arkynd within the flame.

tl;dr

the stone age was a bit like the Old Testament, nine mortals kill god and become pseudo-gods (archons) of magic, each founds a school of magic, now most of them wander in disguise (like Odin).

By pure accident, as all magic after it has been, and shall be.

Little things here and there. One tribe of hunter gatherers ate a plant when the moon was full, it dulled their pain, and suddenly became terrifying warriors. A wanderer witnessed a strange phenomenon in a wild place and wondered if he could make it happen again. Two young nobles tried out-oathing each other before a battle until one found himself in spirits and untouched in battle. An aged, lonely farmer with poor soil left a portion of his weak crop to rot in despair and found it gone the next day, his next harvest was bountiful.

No one knows where it really first ever came from, it's all incidents and stories, things that got people thinking and eventually they wondered how deep the rabbit hole went.

Steal your origin from one of the African mythologies.

Magic and language are one and the same. Man was created without language, and incantations for magic are just sentences in the language of the gods.

"K'ratha belbas dor!" is simply god-ish for "rot from within."

Arguments between the pantheon tend to cause problems on the planet below, which created oceans, mountains, and, accidentally, life.

depends on how magic works