Rune Mage

After your hours of trial and error to learn new spells; you learned how to tinker and augment your spells into your own. You do this by discovering runes throughout your world, and experimenting with them to see what happens; possibly adding powerful new effects to the spell, or leading to consequences.

You can draw runes you find into your book to keep them for later, but you must expend the rune, in order to try and improve a spell. The possibility of the rune working or not depends on the level of the rune used, and the lowest level of the spell you want to improve.

On top of this, you can make blank runes to keep the amount of unprepared spells you have to a minimum. 

Magic Tinkerer

At 2nd level you learn how to effectively identify magic, and use your runes.

You get proficiency with Arcana.

Rune Magic

At 2nd level you collect runes you find in the world and put them in your spellbook. At any time, you can take one of your runes and try to connect it to one of your spells.

When you do this, make an Arcana check, with a DC of 10, plus the lowest level of the spell you're trying to augment. The DM can increase or decrease the DC depending on the power of the rune.

If you succeed, the rune is consumed, and the spell gets their effects. This could be a glorified permanent metamagic on the spell, to completely changing the spell. The effect depends on the rune, and the type of spell you added the rune to. You can only put one Rune on a spell. 

If you fail; the rune is destroyed, and you make a roll on the wild magic table.

 

Expected Cataclysm

At 6th level you learn quickly from your failures as a Rune Mage for later experiments.

You get expertise in Arcana.  

 

Rune Preservation

At 10th level your runes never need to recharge.

All Rune spells can be cast at their lowest level at will. Casting Rune spells at higher levels than that still uses the respective spell slot.

Rune Creation

At 14th level, you have mastered the art of the rune, and have learned how to imbue your own runes with magic.

You can use a short rest to draw a Rune of your own into your spellbook. Describe what you want the rune to do to the DM. The DM decides the level of the Rune based on what it does.

Rune Spells

All spells with any Rune on them are Rune spells. And don't need to be prepared, or have your spellbook on you to cast those spells.

At 2nd level you use your basic ability of creating runes to attach those spells to yourself. You can choose two of your spells in your spellbooks to put a blank rune on.

You can make more blank rune spells at 3rd, 5th, 7th, 9th, 11th, 13th, 15th, and 17th level