This is an idea I have for a submission but I'm not sure how to do submission or whether this thing is in the right format.
While running an adventure for extreme novice characters (0-level characters in AD&D parlance) one of them chanced to gain enough experience to become a wizard during the adventure. He then asked if he could cast a spell from a scroll the party had found earlier. I initially said no because he hadn't cast the Read Magic spell on the scroll in order to decipher it so that his character could read and cast it. In a fit of annoyance he then noted that no wizard should be able to cast any spell, since they'd first have had to have cast Read Magic to decipher the writing, but they couldn't do that without first being able to learn the Read Magic spell, which they couldn't do without having first cast the Read Magic spell. And the fellow was right. It was an absurd catch-22 and I was forced to improvise a solution, the refinements to which follow below.
Before they can do anything more, wizardly spell caster need to be able to do two things. First, they must be able to decipher the mystical scripts that allow them to shape magical energy into the desired spells they wish to cast. Secondly, they must be to detect those mystical energies that comprise the spells that they use. Thus, Decipher Magic and Sense Magic are two skills that a wizard must possess in order to cast wizard spells, with Decipher Magic being a prerequisite to learning Sense Magic. Unfortunately, I am required to use terminology associated with 2nd edition Advanced Dungeons and Dragons as I describe these skills below. I will attempt to explain the terminology as I go so that those wishing to apply the information in this article more broadly may do so.
Decipher Magic (1 Wizard Non-weapon Proficiency Slot Intelligence 0) [Wizard indicates the class that favors this Proficiency. Other classes may learn the proficiency, but it costs them an extra slot to do so. Proficiency slots dictate the number of skills available to an AD&D character, which is determined by their profession/class, Intelligence and level (how advanced they are in their chosen class/profession); Intelligence is a core AD&D attribute, which governs memory, analytical reasoning and the ability the process new information.]
Characters making a successful Decipher Magic check can read and understand a given piece of magical writing equivalent to one spell. Decipher attempts require one full hour for every level of the spell, so a sixth level spell requires six uninterrupted hours to decipher. Note that reading and understanding does not necessarily give the ability to learn or cast the spell. Wizards (for the purposes of this article, I will classify anyone able to cast wizard spells, such as bards, as wizards) may attempt to cast a spell from a scroll (but not a spell book) if they succeed in their checks. Actually committing the spell to their spell book and learning it still requires a successful "Chance to learn spell" percentile check.
The Decipher Magic checks are modified by the power/complexity level of the spell the character is attempting to decipher. In AD&D terms, subtract the minimum level at which a wizard could learn and cast the spell from the level of the character attempting to read said spell. Thus, a second level wizard attempting to decipher the Cone of Cold spell, which is learnable only when a wizard reaches ninth level, would suffer a -7 penalty to his attempt to decipher and read the spell.
Additional modifiers come into play if the would-be decipherer is a Specialist wizard (one who focuses deeply on one type or school of magic at the expense of understanding other forms as well as a regular wizard would). A Specialist attempting to decipher a spell within his specialty receives a +3 bonus modifier to his check. If he attempts to decipher a spell outside his specialty, he takes a -3 penalty to the attempt. Should he attempt to decipher a spell from a opposition school to his specialty, he takes a -6 penalty and even if he succeeds in his decipher attempt will be unable to learn or cast the spell.
One final consideration is that the wizard attempting the deciphering must be able to speak and read the base language of the spell. Elves tend to write their spells in Elvish, Gnomes write in Gnomish, Humans write in Common or the language of their nation. Consider, if you can't read Russian, how could you even hope to decipher a message not only written in Russian but placed in a coded cipher as well?
Sense Magic (1 Wizard Non-weapon Proficiency Slot Wisdom -2)[As noted above, this is a Wizard Non-weapon proficiency governed by the wizard's base Wisdom with a penalty of -2; Wisdom is a core character attribute that governs a character's willpower, observation/perception and good judgment.]
Characters making a successful Sense Magic check may search for magical radiations from active spells, mystical items and the like in up to a 10 foot by 10 foot by 10 foot area. This search takes 10 full minutes to complete, regardless of the area searched. Once a search is completed, the wizard must make another proficiency check to search another area. During these searches, the wizard's attention is completely consumed by his attempt to sense mystical energies and he is extremely vulnerable to molestation or attack. Effectively, the wizard is treated as though he is deeply asleep. So an enterprising pickpocket could easily rob a wizard blind while he attempts to sense magic. If someone attempts to prematurely revive him or he is struck for physical harm, he must still make a proficiency check to bring himself out of his meditative state. Most wizards bring trusted companions with them when attempting to sense magic or perform the action within the safety of their own secured homes.
Readers knowledgeable about AD&D may note that Sense Magic and Decipher Magic are learnable non-weapon proficiencies and not simply wizardly special abilities. This does mean that characters unable to cast wizard spells may potentially learn these proficiencies at the increased cost of one extra proficiency slot each. While the usefulness of Sense Magic to a non-wizard may be obvious (it's much easier to find mystically imbued items with it), Decipher Magic can be useful as something other than a prerequisite to gaining Sense Magic. Consider the case of a warrior deciphering a wizard scroll. While the warrior cannot use the spells himself, once he knows their capabilities, he may receive bonuses to Spellcraft, an Intelligence-based proficiency that allows successful checks to identify a spell being cast. Also, a warrior who knows the contents of a spell scroll is in a much better bargaining position should he desire to sell or trade the scroll to a wizard as he knows the value of the goods he's exchanging. At the DM's discretion, a person who has already Decipher a spell may aid another character in deciphering the same spell. Such aid allows the helping character to add his unmodified experience level to the new decipherer's for the purposes of deciphering the scroll Also, having help reduces the time needed for a new person to ten minutes per level of the spell instead of an hour per level as mentioned above.
(Example: Fifth-level Warrior Martin has Deciphered a scroll with Ice Storm, a fourth level spell requiring a wizard of seventh level to be able to learn it. The party's previous wizard is dead and a new fourth-level wizard, Rufus, who has not Deciphered that spell scroll has just joined the group in defending a small village against a marauding band of orcs who will arrive within the hour. Martin helps Rufus Decipher the spell. Even though Martin must apply a -2 penalty to his level for not being a wizard, he's still able to give Rufus a +3 bonus to Decipher the spell which negates the -3 penalty Rufus would've had allowing him to make a Decipher check at base value. Rufus succeeds and does so in only forty minutes, which will allow him to use the spell to give the arriving orcs one heck of a cold shoulder.)
Should the checks for either Decipher Magic or Sense Magic fail, the character may not make second attempts until he has either gained a level of experience or raised the attribute governing the proficiency in question (Intelligence for Deciphering, Wisdom for sensing).
As a final note, neither of these proficiencies needs to replace the spells Read Magic and Detect Magic which should remain available and common. These spells duplicate and expand on the abilities conferred by the above proficiencies and do so without incurring the drawbacks of time consumption, limited translation, and the chance for failure or the potential for helplessness. Of course their main drawback is that they are spells which last only a limited amount of time before they need to be prepared again by the caster. Given that drawback, the above proficiencies are better than nothing.