Tuesday, June 20, 2017


One of the projects I plan to undertake -- though not at this time -- is to establish a method for quantifying spell effects (by number of targets affected, duration, magnitude of damage or other effect, range at which spell can be cast, and so on) and apply this method to the existing spells. I want to do this so I can compare the relative strength of spells currently considered to be the same spell level. Let's call this quantified spell strength "spellpower."

Once I can perform such a comparison, I can set quantities of spellpower which mark the border between first- and second-level spells, second- and third-level spells, and so on.

The reason I want to do so stems from the fact that some spells, as they are written now, provide a measure of scaling based on the caster's level. To take a well-known and classic example, the traditional Magic Missile spell produces 1 missile of 1d4+1 damage at 1st level, two missiles at 3rd level, three missiles at 5th level, another at 7th and finally another at 9th. Thus, Magic Missile remains a useful first-level spell even when the character has gained a lot of experience.

But why does this scaling of the effect this go as far as 9th level, and no further? That's the question I want to address: once I've quantified how much spellpower each additional missile is worth, then once the point threshold for a 1st level spell would be exceeded by adding an additional missile, the spell has reached its maximum capacity for scaling. To wit: suppose that my calculations determine that the cap for 1st level spells is 1000 spellpower, that the single-missile version of the spell costs 400 points all together, and that each additional missile costs 300 spellpower. Then, the spell would scale to 3rd level (one additional missile: 400 + 300 = 700) and to 5th level (two add'l missiles: 400 + 300 + 300 = 1000) but no further, as additional missiles would exceed the first-level cap.

In addition to the above usage, quantifying spellpower will also lay the grounds for player mages to construct their own spells, first by modifying existing ones, and then by creating wholly new spell recipes ... all at some cost, of course.

Obviously some experimentation will be needed to determine appropriate spellpower thresholds, and once that is done, there will naturally remain the large task of modifying spells which ought to be of a certain spell level so that they are reasonably close to their brethren.


  1. Hello,

    That's a mighty endeavour you're going to get into ! And very much useful too, for spell creation.

    I'm noting that a mage could want to recreate all their X-level spells at their max possible spell power. For example, a 1st level mage would create a 1000 SP Magic Missile spell, with 3 Missiles from the beginning. Even if the wizard is higher level, it can be a boon for one's apprentice, and would very soon replace the Magic Missile spell.

    Maybe there are 2 SP ranges, one for the "base", one for the "max effect" ?

    Anyway, great endeavour !

  2. I realize you're just spitballing here, but I've personally always found Magic Missile to be more or less useless at first level, and to only get marginally better from there on out.

    For combat spells that deal direct damage, it's probably fairly easy to quantify their utility, but I see this as much more difficult for the "utility" spells. How good is "knock"? Or "Tenser's floating disc"?

    I think you'll find the "why" of a lot of these things - like "why does it scale to 9th level and no further" - to not have a satisfying answer. It's that way because Gygax decided it was so. This was a time before powerful desktop computers for monte carlo simulations and extensive playtesting, so it was really just his feeling or intuition that informed most of these decisions afaik.

    On that note, though, for the combat spells, might be worth looking into monte carlo simulations that include the spells. I believe Delta has been doing some work in that field - using monte carlo simulations to empirically quantify monster strength.

    1. Sorry to leave you hanging so long, Charles.

      I agree that the "why" for such things is non-existent. That's why I want to make a magic
      system which CAN stand up to such questions. I want consistency. I want a PHYSICS of magic underlying the spells which exist in the game world, such that it is possible to characterize existing spells as points in some high-dimensional space of possible spells. And naturally, processes that produce magical effects which be bound by that physics. A fire beetle's gland has within it a certain level of latent energy that produces a weak light: I want that energy quantified and I want the answer to "how many glands do I need to brew a Light potion?" to depend on the desired potion effect duration, the size of the batch, etc.

      Yes, Knock would be hard. No answer from me yet. But Floating Disc seems amenable to an approach in which the ability to produce force is quantified and "priced" in SP. This would open the door to quantifying spells like Gust of Wind or the basic Hand spells, which are used to move things about and which are (to a first approximation) defined primarily by the maximum size of object they can toss around.

  3. How do you account for the various elements or components of a spell?

    For example, most 1st level spells have a fairly limited area or number of targets; only a few feet or only a few individuals. If you define a burning hands spell as affecting a greater than 15' cone, does that push it into the 2nd level range? If it does, do you need to adjust the damage so it compares to other 2nd level spells? In other words, while I love the idea of using a quantifiable value for measuring a spell's power rating (especially since I'm rewriting the spells for my game), is it even possible to achieve that level of distinction?

    It sounds very much like the same problem the game's designers had when trying to assign fair XP values for monsters - their abilities, like poison or petrification, are simply too situational to quantify with numbers.

    1. The phrase "adjust the damage [or other variable] so that it matches other spells" is halfway correct. Yes to "adjust the other spell variables," no to "in order to match other spells."

      Remember: under this system, 1st, 2nd, 3rd, etc. are ranges of SP, and do not carry any meaning. They are just useful pointers to the actual concept, which is a minimum and maximum SP.

      If adjustments to Burning Hands make its cost fall into the 2 SP range, then I would either adjust it down to be in the 1st level range OR I would adjust it up as far as possible while remaining level 2.

      The goal would be that, given a certain scheme for costing the parts of the spell, for all spells I want to be level 2, I would probably push them two the maximum amount of power achievable without straying into level 3.

      As of now, some spells are more powerful than others in the same level. Perhaps that is unavoidable. But getting them CLOSER to parity is one of the goals of this system.

      I think I am missing some piece of the explanation so I apologize if things are still unclear. Can't unpack it all right now, sorry, it's not lining up in my head.

      Oh, one more thing, which maybe is obvious already: in the same way that the economic system binds my hands when it comes to determining the price of a given good, the spellpower rating system would bind my hands when it comes to declaring whether a given spell is 1st or 2nd level. Naturally, as I developed the system I would have to tweak the SP ranges that correspond to each spell level.

      But right now I'm not working on this system, unfortunately. I can't drum up any players so I'm kind of feeling unmotivated. I chip away at the rewrite of the econ system but for whatever reason I'm having trouble biting the bullet and digging into the problem areas.

      Anyway, thanks for writing, Ozy. I'm always glad to see someone work their way through the blog, especially when I recognize their name from Alexis's following or from the blogosphere (as with Charles Taylor.)

  4. Glad to be of service.

    I love the idea. And I think I see your point: quantifying these values gives us the ability to objectively rate a spell in a way that answers the question, "Is this too much power?"

    We need a baseline for comparison, though. Like, damage from a spell is worth 10 SP for every 0.5 of average damage. That way, we can create a relationship to non-combat effects. Gust of wind creates a burst of air in a tight area. The duration of the effect, the area, whether there's a saving throw or not ~ these things will increase the SP. But let's focus on the strength of the wind. If we know that 0.5 average damage = 10 SP, then let's ask the question, "What does 10 SP worth of wind strength look like?"

    Yeah. I'm sold on the concept. Time to get working...