Class Variant: Gambling Caster

[Gallade]

I was hoping for something like... take a risk and gain something cool if successfull...

For example. ..

Cast fireball and then gamble... 1-3 you are hit by the spell (backfire) and 4-6 your opponent is hit twice by your fireball...

Then later it could be something like. ..

4-6 apply free empower and maximize to a spell

Later again something like

3-6 your opponent is hit twice

And

3-6 free metamagic stuff

I do like the cards thingy for a boardgames type of d20 session. ..

It would be cool to make lot of cards with spells on them for the caster classes

... very HQ like

It's a trade of quantity versus certainty. The more your spell list grows, the less chances you have to draw the spell that would be best in your situation, unless you make decks with only two spells of the same level (and even then you lose in variety or raw power since you'd have to use higher-level slots for lower-level spells). The idea with the multiple decks feature is to make decks whose spells are useful in a certain situation (Say, making a "defense" deck with Mage Armor, Shock Shield, Blur and Silk to Steel, and an "attack" deck full of Fireballs and Lightning bolts).
The features gained at higher level add more risk/reward, expending multiple casts for a single spell but improving its performance.