On Meier, Frankenfeld’s Laws are well-known principles of magic. They are named for a gnomish researcher who lived ca. 108 OC, but they remain valid today, at least for mortal magic. (Spells like miracle still count as mortal magic.)
No arcane, divine, natural, or alchemical effect can resurrect someone who has died of old age, forcibly recall an unwilling soul from the afterlife, create or destroy true love, or allow time travel to the past.
Any magic item which can reproduce the effects of miracle or wish can have no more than three charges, which cannot be renewed.
Corollary to Second Law
Items can duplicate specific effects that only miracle and wish can create, such as a tome of understanding, but such items can duplicate at most five applications of the spell.
Any spell which creates valuable items has a material component greater than or equal to the value of the items it creates, unless the items are temporary in nature.