This is a good idea.
It allows spells to be copied and thus used more than 6 times.
It thematically fits entropy because
multiple molecules is entropically favored compared to
1 molecule.
Another questions for the community to decide:
Is the chance to copy checked before or after the original spell resolves?
If it is before then the copy would have the same targets as the first spell. (Doubled spell option)
If it is after the spell resolves then it could have different targets if it is a targeted spell. (Split spell option)
I prefer Split over Doubled although it is more powerful and requires more clicks.
I personally going mostly off gut reaction think that at the current price either 50% chance of copying for no extra cost or it should be 100% chance but with full extra cost with
Advanced spells not being copied.
