How to Design Spells

[mearls]

Hello all,

I've started a new section on my web site that might be of interest to current and would-be d20 designers. My So You Wanna... series covers a few basic formatting and practical concerns in putting together d20 material. The first entry is on spells. Basically, I draw on almost 3 years of d20 design to show you the nuts and bolts behind preparing and presenting spells for a manuscript.

NB: This is not an essay on how the design the mechanics behind a spell. Instead, it covers the practical matters of formatting and presentation. If you want to write freelance, this is the kind of stuff that makes editors' lives easier and helps you score more contracts.

Here it is:

http://www.mearls.com/soyouwanna/design_a_spell.html

 

[d20Dwarf]

Errata! Just kidding.

A helpful note that I discovered when writing an article full of spells recently is that spells with

Range: Personal

are always

Target: You

and do not have the Saving Throw or Spell Resistance lines.

Casting Times are fairly standard: 1 action, 1 full round, 1 minute, or 10 minutes, with the first two being by far the most common.

Durations are also fairly standard: 1 round/level, 1 minute/level, 10 minutes/level, and 1 hour/level being the most common.

 

[Wulf Ratbane]

I went through a lot of time and effort deconstructing the SRD spells for the spell design appendix in Heroes of High Favor: Elves.

It covers many of the same things that Wil points out and some things which (if I recall correctly) mearls skimmed the surface of with his work in the Spells and Magic book.

I will be happy to share that section (by PDF) with any writers who'd like to see it. Just drop me an email.


Wulf

 

[mearls]

Wil,

Thanks for the pointer. I'll update that page to include that tip.

Wulf,

Heroes of High Favor is probably my favorite line of builder books so far. My current PC is set to start taking levels in coal tongue raver. The elves book is very useful, and I'd definitely advise anyone interested in spell design to take a look at it.

(As an aside, I wasn't involved in Spells & Spellcraft. Deconstructing monsters and the CR system is my big thing. Those interested should check out The Monster's Handbook, the definitive guide to making cool monsters, from Fantasy Flight. A preview is available at:

http://www.fantasyflightgames.com/llmh.html

This gratuitous, shameless, utterly uncalled for plug ends NOW.)

 

[Darrin Drader]

Design spell
Necromancy [Death]
Level: Sor 5, Wiz 5, Death 4
Components: V,S,M
Casting Time: 2 hours
Range: Touch
Target: One brainstem
Duration: Instantaneous
Saving Throw: None
Spell Resistance: No

Upon casting this spell, a new D20 spell is designed correctly. However, in doing so, the caster's brainstem is throttled severly and must be immersed in curative tonic (at least 80 proof) for 8 hours per casting. Failure to take the necessary curative steps results in the caster type changing to undead for 1d4 days. During this time the caster takes on all the traits of an undead creature and may not attempt to do any further game design until the creature type returns to humanoid.
Material Component: A pair of handcuffs, a banana peel, and a bag of cheezy puffs.

 

[Wulf Ratbane]

Wulf, Heroes of High Favor is probably my favorite line of builder books so far.

Thanks, Mike! I consider that high praise.

My current PC is set to start taking levels in coal tongue raver.

That makes me twitter with girlish glee.

(As an aside, I wasn't involved in Spells & Spellcraft.)

I was actually thinking of MAGIC, and the Arcana chapter... I would have sworn that was yours.

Deconstructing monsters and the CR system is my big thing. Those interested should check out The Monster's Handbook, the definitive guide to making cool monsters, from Fantasy Flight. A preview is available at:

http://www.fantasyflightgames.com/llmh.html

Better you than me! That's as big a beast as the nebulous D&D spell system. I will definitely check it out. Will the system you presented there tell me exactly how much adding any given special quality (esp. DR) will increase the CR of a creature?

Maybe we should talk...

Wulf

 

[jaerdaph]

(As an aside, I wasn't involved in Spells & Spellcraft. Deconstructing monsters and the CR system is my big thing. Those interested should check out The Monster's Handbook, the definitive guide to making cool monsters, from Fantasy Flight. A preview is available at:

http://www.fantasyflightgames.com/llmh.html

This gratuitous, shameless, utterly uncalled for plug ends NOW.)

Just wanted to say that I think the Monster's Handbook from FFG is probably one of the best investments you can make for your d20 collection - it adds value to every monster sourebook you own. It's an excellent book.

 

[mearls]

Darrin,

Let's not forget the cantrip design spell incorrectly, an incantation proven to drive editors completely insane.

Wulf,

Yep, the book tells you how to modify the CR when adding abilities. It does exactly what you're looking for. The one down side is that you can't create creatures from scratch (yet). IMO, once 3.5 is out I'll be a month of work away from creating a system to allow the design of each creature type from the ground up, balanced by CR against other creatures.

BTW, my email is mearls@alum.dartmouth.org. Feel free to drop me a line.

Joe,

The check is in the mail. I mean, thanks for the unbiased, unpurchased, completely not paid for with cash praise.

 

[Wulf Ratbane]

IMO, once 3.5 is out I'll be a month of work away from creating a system to allow the design of each creature type from the ground up, balanced by CR against other creatures.

Mike, that's awesome. As much as I complain about all the work and math and tweaking that went into culling those spell design templates from the spells in the SRD, I just friggin' love that kind of roll-up-your-sleeves, get-under-the-hood kind of design work.

Like the spells, I am sure there are some creatures that will just never hit the "official" WotC Challenge Rating once you rebuild them, but having such a ground-up reference work is a HUGE benefit for the d20 community.

Not to pick on any publishers specifically, but it's clear a lot of folks need help with CR, and I just don't buy the line that "it's an art, not a science."

There is an awful lot of science in the way that 3e was designed, especially the integration of character level/CR/XP and all. There better be a "unified" mathematical formula at the heart of it all.

Wulf

 

[Word]

CR Formulae

There is an awful lot of science in the way that 3e was designed, especially the integration of character level/CR/XP and all. There better be a "unified" mathematical formula at the heart of it all.

Wulf, I've gotta disagree with you on this. While, on the one hand, I think it's a terrific idea for designers to get under the hood and give the average player a system to easily construct monsters and place them confidently in the framework of the greater game, I also think such a system would be necessarily constrained in its overall utility. Not all of the most interesting monsters conform nicely to every adventuring group, or, so, to the CR scale, but they're part of the great creative empowerment of 3E.

If I want, for example, a monster that's a spinning pile of chains (MMII), then I just create a new ability for my monster that lets him spin around. So long as I have the freedom to invent any special ability and define it within the rules, the CR system is going to be a little fuzzy. I think it's better that way.

Not every adventuring group is alike, and it's not safe to assume too much about a PC party when you assign CR. It's not a sound practice, for example, to decrease a monster's CR because it is somehow vulnerable to clerics under the assumption that every PC group has a cleric. It's not safe to assume that the PCs will have a wizard with them who can counter another monster's powers. To some degree this happens, to be sure, but that's where the art comes in; the factors of experience, familiarity with the rules and flexibility. These things won't be genuinely modeled, in my opinion, by a formula.

One answer might be to offer discreet advice in the monster's entry on how a given monster is or is not a suitable threat to certain character types, but I think that's best left to the interpretation of the DM (since realizations about monster-character interactions are part of the fun that comes out of the skirmish game, in my experience). The more common answer is that the CR system needs to be revised or tweaked or strengthened.

Whatever mathematical forumla you come up with isn't going to be flexible enough to accurately position each monter on the statistical scale against every group of PCs, every strategy, every wacky fantasy world or every home-grown spell, class, weapon or other monster. The system needs to stay flexible to stay broadly applicable, I say. DM judgement needs to be preserved as an overriding factor in CRs.

I submit that DM education is the best method of appreciating the value of the CR system. DMs need a good guide on how, when and why to set a CR, adjust a CR and spot a CR that's sound for one group, but maybe not for theirs. I think this topic's more about game theory than it is about the statistical model.

As evidence, I hold up the separation of CR and EL in d20. A monster's CR is meant to be fixed, but the EL it appears under is supposed to be the flexible scale a DM has to get a sense of real control of the system. The malleability of ELs has gone underused, in my opinion, by adventure and game designers. An EL can convey a lot, suggest a bit more, and give more leeway to the interpretation of a CR. A monster's context can't render its CR invalid, for example. An EL is still only mildly more valuable to the average DM. Only a given party's DM can accurately assess the relationship between a monster, the encounter and her party.

Or so says me. I've written half a column on this right here, so I tip my hat to whomsoever has indulged me this far.

Totally different point: Wulf, is Bad Axe still in Lombard? I'm from the La Grange area originally.