Called Pipeweed of Metamnemonic Inspiration or Smokeables of Arcanocogitation in certain sources, the Wizard's Mix combines a particular variety of the standard halfling smoking herb with other potent ingredients, perhaps henbane or mandrake or saints know what else. When available for sale a pouch of Wizard's Mix will be good for d6 smokes and cost d6 x 100gp.
To employ the Wizard's Mix a pipe and source of fire is required and d6 turns must be spent smoking in quiet contemplation. Others present may engage in light conversation or pleasant singing, but arguments or other loud noises have a 50% chance of ruining the beneficial effects of smoking the pipeweed.
Upon finishing the smoke, the user may roll 1d6 to attempt to refill a currently empty arcane spell slot. If the roll is equal to or higher than the spell level of the empty slot, the spellcaster has received a magical insight whereby a randomly generated spell of the appropriate level appears in the caster's memory. If slots of different levels are empty the die roll is used to decide which spell level is filled (e.g. a roll of 3 will fill a third level slot if available, otherwise it will fill a second level slot before it fills a first level slot). The spell added to the magic-user's memory does not come from the list of spells known in their spellbook, but rather is generated from the total list in the rulebook appropriate for the class (or the DM's house list if such a list is kept), allowing the user access to spells they couldn't otherwise cast.
All attempts to transcribe spells learned under the effect of Wizard's Mix result in pages and pages of total gibberish. In the reverie to put down these new insights the user runs a 50% chance of ruining d6 spells already in their spellbook; while high they don't realize they are scribbling over previous spells.
"Man, is there anything Jeff CAN'T do when it comes to gaming? This guy is like a critical 20 every roll. Jeff can bite the heads offa five game geeks, including their sorry-ass DM, and spit 'em into a large duffel bag ONE AT A TIME!...that's just the kind of messed up bastard he is! You think yer a gamer, punk? Well..do ya? Jeff will depants your weasel-ass right in front of your grandma."