House Rules | Memetic Growth Patterns for Magic-Users

Followers of this blog who've been reading for a while might recall my Vancian MIII memory cell system. What follows is a distinctly simpler smoothing-out of Vancian magic concepts and a light retool of the traditional D&D spell mechanics. 

The Memetic Growth Pattern (MGP) system makes some basic assertions about the nature of spells and spell-casting:
  • Spells are sentient entelechies that have been forced to assume a temporary dwelling place inside a magic-user's mind. In a sense the magic-user must constantly attend his memorized spells in order to guard against spell loss or leakage. For all spells are desirous of freedom. In order to escape a magic-user's mental grip, they must exit his mind in a precise and calculated form. Which is to say, they must become the spell's effects at the time of casting.
  • One of the magic-user's greatest resources is his memory. Memories are like trees -- in infancy they are all but seeds germinating. Eventually they will grow to become stout oaks or massive evergreens. Sometimes they are merely crab apple trees and achieve no great size. The extent of an individual's memory is expanded through learning and experience.
  • A spell's level represents its relative complexity. Low-level castings are brief texts in comparison to the interwoven formulae of spells that occupy the very heights of sorcery.
  • All memory slots are made equal. In order to memorize a third level spell, three slots are required. For a seventh, seven slots are needed. And so forth.
  • A magic-user's total memory slots increase as he gains experience levels. The rate of this increase varies from magic-user to magic-user. It is a unique memetic growth pattern.
I thought it would be interesting to add an element of Carcosa-esque dice randomness to memory slot accumulation. Basically, upon attaining a new level, a wizard must roll a 1d6. The result indicates the dice he will roll to check against his current INT action throw value.
(1, 2) 2d6
(3, 4) 3d6
(5) 4d6
(6) 5d6
I didn't invent this, just formatted it.

If the player fall shorts of the target action throw value when he makes his roll, then he earns no additional memory slots. If he exceeds the target, he subtracts it from his roll to determine the number of slots gained.
eg. Spidertits the Malignant just became a 7th level magic-user. She has an INT of 15. Referencing the table above, that means her target # is 9. She rolls a "2" on her first d6 roll, indicating she needs to roll 2d6. The result of her second roll is 10. Her slots increase by 1.
A corollary to this system is Open Spell Acquisition. Meaning that any magic-user can attempt to learn and/or cast any spell. Some hard/fast rules for this: 

To learn and successfully transcribe a new spell, the player subtracts the spell's level from his character's INT and then makes an INT action throw based on this number. Success indicates that the spell has been added to his repertoire.

To cast an unknown and untested spell, the player must successfully make two action throws like the one described above. Failure on either of these rolls elicits a roll on the Miscasting Table (to be revealed in a future post).  


  1. Huh. OK, at first glance it's intriguing. On second glance, a few things jump out:
    Seems like a pretty good chance of not getting any spells for at least a few levels. (33% chance of 2d6, which will pretty much doom you if Int is less than 17 or 18). Something like a 50% chance of not getting slots at 1st level if Int is 14 or less.

    2 - It's a spell point system. You get X points, each spell is # points = spell level. Select Y spells to prepare, where the total of Y spell's levels = X. That's not a problem, but I didn't catch it on the first glance.

    Interesting conceptualization. Hadn't read the memory cell system before.

    1. To supplement low-level magic-users I would allow them to start with 2d3 spells already learned and included in the spellbooks and repertoires.

      I think that Gary's coding of Vance has always been a point system -- just not worded as such. You always have a set amount of spells you can commit to memory. That could be broken down into a numerical value pretty readily. As you gain levels, you can memorize more. While it's not given as an explicit total, the accumulated capacity for spell storage is always a measurable (pointalizable) thing.

    2. The chief/defining differences that I've seen between point and slot is 3 1st level spells =/= 1 3rd level spell, and slot systems typically cap the number of spells possible at each level. I think those two factors for me, particularly together differentiate a slot from a point system. At a more macro level, slots are a form of point, absolutely.

      I think this is probably the most attractive system "of its type" that I've seen. Points have a way of breaking my suspension of disbelief that slots don't have, and the cells avoid that. I'll have to think about it a bit more. I like it; I think it's interesting; I just have to figure out how something works before I really get into it. :)

    3. You're right -- there's more flexibility here than in the traditional "you only get to memorize this many third level spells ever" -- I wanted to dismantle the various "ranks" of slots and make them all one magic currency.

      I dislike the conventional spell point systems too -- there's no sort of preparation involved when a magic-user can cast any spell in his repertoire at will provided he has the points. I like the preparation aspect -- it jives with Vance, obviously, but it also is another form of resource management that players can hedge their bets with.

  2. yeah, I definitely like the preparation aspect. The best system I've found to my taste was preparing as a wizard, but then casting from the prepared spells as a (3e) sorcerer (so casting did not expend a prepared spell). Didn't have to memorize multiple spells, but there was still a planning aspect in choosing which spells to prepare. Made the 3e sorcerer pointless, which was fine by me - it was a class built around a mechanical gimmick anyways, initially.

  3. I sort of like what I see here.

    What do you think about spell components? I never used them in any D&D games I run but when I run WHFRP the sometimes insanely hard to acquire components made playing wizards pretty hardcore.

    1. I like spell components, especially for higher level spells (say 4th+). You're right -- they can become an adventure all on their own.

  4. I think what'd make _me_ more comfortable with the die rolling when you level up is a bonus to your next roll if you don't hit your TN on this roll. Haven't had time to think about it, so not sure if the bonus would be +1 to the d6, or +2(?) to the 2/3/4/5d6 roll. That mitigates but does not eliminate the possibility of getting diddly squat for multiple levels.

    1. Could be a flat rule to prevent getting completely screwed -- such as a minimum of 1 slot improvement per level.

    2. That'd be fine. My concern is that lower (14/15 or less) casters have a pretty good chance of not getting anything for multiple levels, so a minimum +1 cell gain would take care of that.

  5. And congrats on the yewglum(?)!!!! Looking forward to seeing it!