When you learn a new spell and have time to sit and meditate for a few hours per level on its arcane mysteries roll + INT:
On a 12+ you learn the spell and get to add a detail that makes the spell uniquely yours (to be decided by the player).
On a 10+, you learn the spell without a hitch.
On a 7-9 you learn the spell but there is a new cost or problem that now comes from casting the spell (to be decided by the GM).
On a miss, you learn the spell but it has a disastrous side-effect that now goes along with it (to be decided by the GM).
Judd! This is awesome. Have you seen the mercurial magic tables from DCC, yet? They would be absolutely amazing to use with this.
Reading about you and Bret Gillan playing DCC while reading Dying Earth this week is what inspired this.
Adam Koebel these mercurial magic tables intrigue me. And Judd I really like this idea! I notice DCC is under the OGL but I can’t seem to find an SRD anywhere for it?
Chris Dulsky I have no idea what their licensing is, but I can tell you a little about Mercurial Magic.
When a Wizard learns a new spell, you roll on a table to see how that particular spell does weird crap just for them. You add your Luck bonus and end up with something from catastrophically awful to totally fucking awesome.
The best result:
Instead of a d20 when you use this spell, you roll a d30 instead.
A median weird result:
Two random items near you are transmuted. One into lead, the other into gold.
The worst result:
Every time you cast it, someone you know dies.
=] Time to visit the good ol LGS!