Quick question: Can a magus write lab notes for a spell he knows formulaically, but they have lost their own lab notes for?
If no, how can they recreate their old lab notes for the spell?
It seems to me, that the process described in RAW, always references copying other notes, and that you can only create original lab notes, if you invent the spell in your lab...
Unless they have the virtue Magical Memory, I say they will have to reinvent the spell to get a new set of lab notes if they lost the old ones.
If you normally could write out a new set of lab notes from memory, then the Magical Memory virtue would be nearly useless.
Thanks for the quick reply.
the other possible exception is if they have a memory palace and committed the original lab note to memory there- but this is because at that point they aren't really missing they are just not physically present.
Another explicit exception are spells learned from Twilight, which may be scribed as normal even though the magus never had a lab text for it.
I'd consider giving them a bonus to re-invent a spell they've already invented before, maybe a similar spell bonus.
Its like if you suffer a catastrophic computer melt down and have to re-write a programme/report/etc sure, its a ball ache and really annoying, but you'll remember bits of the original, remember some of the breakthrough moments you had and some of the dead ends. It wouldn't be AS hard as the original.
Of course they would get the similar spell bonus - anything else would be weird. Perhaps even a small additional "identical spell bonus".