Designing Dynamic Spells

A-Z 2015 "D"I’m parking the autoscaling magic items idea for a few days while I let my subconscious work on it. I’ve already got posts planned for Monday and Tuesday (‘E’ and ‘F’ — Earth Gods of the Tetratheon and Fire Gods of the Tetratheon respectively).

Today, though, I’m going to look again at something I’ve wanted to get back to for a while: meta-spells. Spells that replace several related spells with a single one that can be used to varying effect.


Examining the Pathfinder® Roleplaying Game Core Rulebook™, I see there are 623 spells. Of these, it looks like 261 can be pretty trivially merged into new spells that vary either in degree by level (such as the various cure wounds spells that basically do (spell level)d8 + caster level (to a maximum caster level equal to five times the spell level) points of healing. And the mass cure wounds spells that do the same but are four levels higher and allow a ‘maximum caster level’ twenty higher than the base spell.

That’s awkward to describe. Try this:

  • Level 1: 1d8 + 1/caster level (max 1d8+5)
  • Level 2: 2d8 + 1/caster level (max 2d8+10)
  • Level 3: 3d8 + 1/caster level (max 3d8+15)
  • Level 4: 4d8 + 1/caster level (max 4d8+20)
  • +4 levels: ‘mass’ version healing up to one creature per caster level, with a maximum healing 20 points higher than the base
    • Level 5: 1d8 + 1/caster level (max 1d8+25 to one creature per caster level)
    • Level 6: 2d8 + 1/caster level (max 2d8+30 to one creature per caster level)
    • Level 7: 3d8 + 1/caster level (max 3d8 +35 to one creature per caster level)
    • Level 8: 4d8 + 1/caster level (max 4d8+40 to one creature per caster level)

In the Pathfinder® Roleplaying Game Core Rulebook™ this is eight spells. Simple examination makes it pretty easy to reduce to a single spell with effects that vary by spell slot applied.

I could even double it if I allowed the spell to be ‘reversed’ the way it used to be in older editions.

Prior Art

There are games — D&D-based games — that use spells and powers that can be defined this way.

  • Dungeons & Dragons 3e psionics rules had psionic powers that started at a base level for a base effect, but could be increased by spending more psionic power points and increasing the ‘initiator level’, with a limit of spending psionic power points equal to the character’s initiator level. In the case above you might get the base effect (1d8+1 hit points) for one power point, 2d8+3 for three power points, 3d8+5 for five power points, and so on. You could instead increase the initiator level by eight (spending eight more power points) to heal multiple creatures (1d8+9 to nine creatures for nine power points, 2d8+11 to eleven creatures for eleven power points, etc.)
  • 13th Age spells below ninth level have a base level of effect and will gradually be learned at a higher level for greater effect. The effects do not necessarily increase in size (the base effect of cure wounds lets the recipient heal using a free recovery, at higher levels it allows additional saves against effects, a chance of recharging the spell, allow additional free recoveries, and so on). The spell
  • Many or most Dungeons & Dragons 5e spells can have greater effect when cast using a higher-level spell slot. For instance, cure wounds heals a base of 1d8 + casting ability modifier as a first-level spell, and an additional 1d8 points of healing for each slot higher. Many spells do not. Looking at this spread of the Basic Rules in front of me, charm personcommandcone of coldcure wounds, and delayed blast fireball all have scaling options, while communecomprehend languagesdancing lightsdarknessdeath warddetect magic, and dimension door do not.
  • Dungeons & Dragons 4e behaves much like 13th Age on cure wounds, as far as I can see. However, many powers — combat-oriented or not — were expected to be replaced by more powerful or functional powers (and possibly by powers more or less unrelated to the one being replaced) at higher levels. Some will scale, some will be upgraded.
  • Monte Cook’s Arcana Unearthed spells often could be cast Heightened or Diminished (using a spell slot one level higher or one level lower, respectively).

It looks like there is a place for dynamic spells. But how do you design them?

Designing Dynamic Spells

It is quite simple to design a dynamic spell, really. Find some closely-related spells (such as the cure wounds spells or planar binding spells). Examine them to see how they differ and work out the pattern between them.

I described cure wounds above, and planar ally is almost as easy.

  • lesser planar ally is a fourth-level spell that allows the caster to call one outsider with up to 6 HD, costing offerings of 500 gp + payment for services.
  • planar ally is a sixth-level spell that allows the caster to call up to three outsiders of the same type with a total of up to 12 HD, costing offerings of 1,250 gp + payment for services.
  • greater planar ally is an eighth-level spell that allows the caster to call up to three outsiders of the same type with a total of up to 18 HD, costing offerings of 2,500 gp + payment for services.

Payment for services is proportional to HD of creatures summoned (amount by nature and duration of task, times number of HD).


  • Level 4: one outsider of up to 6 HD. Costs offerings of 500 gp + payment for services.
  • Level 6: up to three outsiders of the same type, up to a total of 12 HD. Costs offerings of 1,250 gp + payment for services.
  • Level 8: up to three outsiders of the same type, up to a total of 18 HD. Costs offerings of 2,500 gp + payment for services.

Nothing else appears to change between the levels, so this should cover the ‘dynamic’ element of this cleric spell. The remainder of the spell summary and the spell description can be largely taken from the lesser planar ally spell definition.

There is room for some expansion if I want, though. I could add

  • Level 1: one outsider of up to 1 HD. Costs offerings of 100 gp + payment for services.
  • Level 2: one outsider of up to 3 HD. Costs offerings of 250 gp + payment for services.
  • Level 3: one outsider of up to 4 HD. Costs offerings of 400 gp + payment for services.
  • Level 5: up to three outsiders of the same type, up to a total of 9 HD. Costs offerings of 900 gp + payment for services. (Or up to two outsiders to a total of 8 HD; I’m not sure)
  • Level 7: up to three outsiders of the same type, up to a total of 15 HD. Costs offerings of 1,750 gp + payment for services.
  • Level 9: up to three outsiders of the same type, up to a total of 21 HD. Costs offerings of 3,500 gp + payment for services.

In most cases the base spells are similar enough that examination and consideration should be enough to indicate the effects at each level. Because the spells are so similar it should be possible to largely use the text from the spell the others refer to in their own definition.



  1. I love the idea of dynamic spells. I like to keep things as simple as possible, so if you could use 1 spell instead of 8, I would love that. I like the 5e rules of using spell slots to make more powerful spells too. The other option I like is having points to spend and making spells more powerful by using more points.

    • I’ve learned to take baby steps. I found the 3e psionics model very practical in its approach, and it solves so, so many things for me. I’ve heard it described as “the best D&D magic system ever”, and while I think that’s largely a matter of taste I don’t think I could find a stronger argument against that assertion.

      However, right now I’m aiming at a Pathfinder crowd, and I’m pretty confident that moving from spell slots to spell points would cause many people to choke.

  2. I actually went through all of the CRB, APG, UM, and UC spells and added heightened and diminished effects. With the cure spells, this resulted in my combining them into three spells at 1st, 4th, and 7th level. There were many more spells I combined as well. They are available for free on my blog and I am also publishing them as PDFs via Publishing.

    • Indeed, I was quite excited to see you start that series on your blog and I’ve got the first four PDFs :)

      I think we’re doing slightly different things, though. Your spells are modeled after Monte Cook’s Arcana Unearthed. It’s a good model and I like what it does.

      I’m following something probably closer to the D&D 3e psionics rules, where there is a base effect that scales (potentially indefinitely) with level. In the psionics rules the caster level (psionics points spent, which cannot exceed initiator level; for my purposes in conversation this is ‘caster level’), I’m looking at spell slot used.

      I think you allow for greater variance in effect than I am, mostly. For example, the continual flame spell can be diminished for the equivalent of a light spell. I probably wouldn’t do that because the trappings of the spells are different in the PRD — light causes a glow equivalent to a torch, continual flame creates an unburning flame otherwise equivalent to a torch. I realize it’s a minor matter, but I can see myself not linking the two because of it.

      I think we don’t quite duplicate things, though there are certainly overlaps and parallels. And I have to say that some of the heightened or diminished effects look like they could make good ‘adders’ (such as the ‘mass’ adder above). For instance, some of the detect spells have a heightened effect that allows them to penetrate twice the normal thickness of potential blocking material; I can easily see that as a “+1 adder”. Similarly for the spells that include analytic effects, gaining the entire payload in one round instead of several (as detect evil) could be another “+1 adder”.

      I could end up with something like

      Detect Alignment
      Level 1: as detect chaos, detect evil, detect good, detect law (limited by caster alignment, etc.).
      +1 level: Penetrating Blocked by 2 feet of stone, 2 inches of common metal, a thin sheet of lead, or 6 feet of wood.
      +1 level: Faster All information gained in the first round.
      +1 level: Analytic Detect all alignments instead of just one.

      Assuming no other adders, this means detect alignment could be cast in twenty different forms at four different levels:

      • By alignment, so each of these could have four variations
        • Normal, first level
        • Penetrating, second level
        • Faster, second level
        • Faster, Penetrating, third level
      • Analytic, all four alignments at once
        • Analytic, second level
        • Analytic, Penetrating, third level
        • Analytic, Faster, third level
        • Analytic, Faster, Penetrating, fourth level

      Now, I don’t know that someone would be willing to invest a fourth-level slot to do this, but I don’t want to rule it out, either.

      Hmm. Another adder might be ‘scrying’, allowing you to use it through clairaudience/clairvoyance — per PRD, “Unlike other scrying spells, this spell does not allow magically or supernaturally enhanced senses to work through it.”. Being able to overcome that limitation might be a valid adjustment, for cost. Perhaps not worth a feat because it is such a narrow application, but requiring a caster to invest a higher-level spell knowledge slot (sorcerer or bard, or wizard because the wizard must know it as a higher-level spell, increasing spell book cost; clerics have it easy).

      I digress. Back to work.

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  4. Raneth

    Deep Magic did something similar by combining animate dead and create undead into a series similar to summon monster and summon nature’s ally.

    This reminds me of the feat- and skill-based magic system used in Green Ronin’s True Sorcery source book. There were a limited number of base effects, but these could be augmented and combined to any number of applications. Green Ronin did the same thing for psionics in The Psychic’s Handbook.

    EN Publishing wrote a similarly versatile magic system in Elements of Magic.

    Misfit Studios’ Spellweaver base class uses a skill-based casting mechanic, though it only replicates existing spells from the core rules. It is very similar in practice to the Chaos Mage from Mongoose Publishing, minus the mutations and poor writing.

    Drop Dead Studios’ Spheres of Power divided all magic into a set of basic themes that were then built upon for various applications, but includes an optional ritual system for using spells from the core rules. It is reminiscent of True Sorcery.

    Words of Power in UM tried to do something like this, but it missed the mark and I don’t recommend it.

      • Raneth

        If you aren’t already aware…

        There is a “Vancian to Psionics” project on GitHub that rewrites the magic rules to use points and augments like psionics, but it doesn’t go into the detail of your dynamic spells.

        The Genius Guide to: 110 Spell Variants and its sequels does something loosely similar, inventing spells that are variants of existing spells to create unique effects.

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