Hello to all, my name is Fabio Milito Pagliara and I am a D&D old player 
to the topic
the idea the a wizard has to “re-write” the spell in his spell book is one that will find great opposition (as happened in D&D 4th edition) so I suggest to reformulate it without modifying the game balance or the system
the system presented in ACK can be seen as one in which the wizard construct in his mind “schemata” (or “sigil” or whatever) for each of the “ready” spell (table + Int bonus), how long it will take to construct this “schemata” (1 hour, 1 day, 1 week)/level and the cost (10 gp, 100 gp, 1000 gp)/level is matter of game balance and I suggest to leave it as for the time of spellbook rewriting
in the book there should be more spell than the wizard can “ready”, I would go with the old spell maximum of AD&D or something similar
an easy one: the maximum number of spell a wizard can “understand” (and thus write in his spellbook for each spell level is “Intelligence-Spell Level” spells
I see what you’re aiming for but I think this makes wizards into stamp collectors and arcane knowledge less elusive. Magic has it’s own rules, counter-intuitive or not.
isn’t the greatest asset of a wizard it’s spell collection?
there are other means to elude the stamp-collector feel
- don’t present too many spell
- put a maximum to the number of spell a wizard can understand and write in his/her spellbook
but to rewrite the spell sounds just “bad” not “magical” at all
I like the rewriting idea because of the way individual wizards may evolve over time, at different stages of their ‘career’ specialising in different spells. High level mages would be drawing on different spells rather than having the same bulging spellbook. Having a narrow selection to draw from helps to balance spellcasters with non casters by limiting the ‘one-man army who can solve all adventures by being able to do anything’ that exists in D&D - invisible teleporting polymorphous deathbringer Gandalf.
I agree with Mr. Wills about how to treat the mage in the game. What became rather troublesome in 3.5 is that the wizard could, in theory, eventually have every spell and craft a bunch of wands and staves so that the right spell could be pulled out at the right time. The versatility of the wizard seemed to overshadow the one-trick ponies of the martial-based classes, at least to popular forum belief.
From a flavor perspective, the wizard just felt watered down because it had access to so many spells from eight different fields. The most powerful option for the wizard was to stay a universalist, and it’s hard to argue for being more flavorful by focusing on a subschool when that flavor required a loss of power.
I think it’s best that the mage stay with a limited spell list, but possess on-the-fly casting.
while I understand the doubt I don’t see (mechanically) the difference between having the need of rewriting one own spell-book at 1 week/level and 1000gp/level to rewrite the spell and the need to recreate the spell pattern at 1 week/level and 1000gp/levelin the wizard mind?
the big difference is flavor