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Old 08-28-2015, 04:53 PM   #1
dataweaver
 
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Default Alternate GURPS: converting Sorcery Spells into Magic Spells

Warning: train of thought coming through.

One of the main complaints I've heard about GURPS Magic is that the spell list is arbitrary and sometimes wonky. That said, it’s full of neat ideas. As I see it, that’s why Sorcery is being promoted: presumably, sorcerous spells are less arbitrary and wonky due to them having been built using the Powers system. For the purposes of this thread, I'm going to assume that that's true.

The idea here is to scrap the spell list found in GURPS Magic except as a source of inspiration for Sorcerous Spells, and then use the core principle found in Pyramid #3/44’s “From Skills to Advantages” article to rewrite the Sorcerous Spells as skill-based Magic Spells — that core principle being that an exotic skill is equivalent to an Ability that works the same way (but needing an Attribute roll to activate) and costs the same as the skill would if bought at the Attribute level.

In order for this to work, you’d need to tweak the Sorcerous Spells so that they always require an IQ roll to activate, possibly also requiring gestures and/or incantations. Then use Costs Fatigue and Takes Extra Time to lower the cost to either 4 or 8 points, trying for a balance between the two. If you get the point cost to 4 points, you can treat it as a Hard Skill; if you get it to 8 points, you can treat it as a Very Hard Skill. Instead of being dependent on Sorcerous Empowerment, the resulting Magic Spell would be enabled by Magery.

Note that the -80% cap on Limitations would mean that you can’t convert any Sorcerous Spell that’s built on Advantages costing more than 40 points, since there's no way to drop its cost down to 8 points. Hmm… since we’re doing an Alternate GURPS thing, how about tweaking the way the Limitations cap works? For example: if your net Modifiers exceed -80%, convert every full -80% you have into a ×0.2 or ×⅕ multiplier; so -100% would become -20% and ×0.2, while -160% would become ×0.04 (two -80%s). That said: the diminishing returns from Limitations as each threshold is crossed, combined by the fact that -160% would bring 200 points worth of Advantages down to 8 points, means that I doubt you'd get as far as -160% in practice.

Doing the above would result in a “flat” spell list, lacking any sort of prerequisite trees. This will be fine for many groups who find the prerequisite trees to be awkward; but some people like having prerequisite trees — and more importantly, the Ritual Magic option tries to convert the prerequisite count into a Technique penalty; doing away with prerequisites does away with learning individual Rituals as Techniques in the Ritual Magic system. So for those who want to incorporate prerequisite chains or Technique penalties into a Magic Spell list derived from the Sorcerous Spells, how might one go about it in a reasonably consistent and rational manner?

Maybe you could resolve the “prerequisite chain” option by borrowing a notion from the “Flexible Magic” chapter of GURPS Thaumatology, where energy cost, skill penalty, and margin of success are interchangeable: that is, let the designer of the spell convert a portion of the energy cost into a “prerequisite count” which can be used as a guide when placing the spell in a hierarchy of spells.

Thoughts?
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Old 09-18-2015, 03:04 PM   #2
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Default Re: Alternate GURPS: converting Sorcery Spells into Magic Spells

I haven't given this a ton of thought, but the post has stuck in my head and I had an idea. Here it is, with little reflection and no playtesting.

Taking a page from Sorcery, we can call all spells alternate abilities of the core "Wizardry" advantage, perhaps built on Detect (Magic). That'll give us an 80% discount right there that takes place AFTER limitations are applied. But it's at the cost of a Ready action and only having one such effect up at once.

Spell Creation

Take an Advantage. Then apply the necessary limitations and enhancements to get the theme you want. Then apply the Power modifier, which will include Requires Attribute Roll. If you're starting with a spell from Sorcery, this step is already done and you just switch the modifier.

If the net modifier isn't -80% already, add Costs Fatigue and either (Takes Extra Time or Preparation Required) to get the cost down until it is at -80% total modifier.

Minor Arcana: If the total cost after modifiers is less than 10 points, then you have a Minor Arcane spell. Convert it to a skill as below. You can cast Minor Arcana whenever you want and sustain as many as you have the FP for. If you have wizardry at all, you can freely learn these spells.

Major Arcana: If the total cost after the -80% is above 10 points but lower than 45, then you have a Major Arcane spell. Take 1/5 the cost (round up). Then convert it to a skill as below. Major Arcana are extra powerful spells that require an extra Ready Action to cast, and you can only sustain one such spell at a time. For spells with Preparation Required, only one such spell may be prepped at a time. Learning one requires more points in Wizardry than the total modified cost of the spell (just like in Sorcery).

(Advantages that cost more than 230 points before modifiers cannot be converted using this system. Perhaps someone can figure out how to treat these "Great Arcana". Perhaps this is where spell prerequisite system can be re-introduced. Perhaps part of the cost of an earlier spell can include some or all of the points in a Latent Ability (Powers p 34-35) for a later spell. We could use this to get all spells to H or VH, with simpler spells being front-loaded with points used for later spells. Anyway, I'll let you think of ideas...)

Convert to Skill

So now, we have a spell that costs from 1-9 points. We use Skills for Everyone (Powers p 132), and From Skills to Advantages (Pyramid 3/44, p 14) and work backwards. What hypothetical Skill+Unusual Training combination would get us to this Advantage?

6-9 points = Very Hard
4-5 points = Hard
3 points = Average
1-2 points = Easy

This was all off the top of my head, so I hope it's not too disjointed. I'll post two examples next.
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Old 09-18-2015, 03:08 PM   #3
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Default Re: Alternate GURPS: converting Sorcery Spells into Magic Spells

And, based on my post above, here are a few examples. A few problems I've noticed. The biggest is that the minor/major arcana distinction depends on the core unmodified Advantage. In some cases I think this over- or under-costs the final spell, or at least inappropriately sets the prerequisites. Lots of spells using Affliction I will therefore be "minor" despite being VERY expensive in FP and casting time.

Spells that are right on the border between Minor and Major are the most obvious cases of this. You go from a VH minor spell to an Easy major spell and the distinction doesn't hinge on the overall power of the spell, just the unmodified base advantage.

Another is the existence in this system of IQ/E and IQ/A spells in the first place; think we could figure out a way to move them back down to IQ/H and IQ/VH. At a minimum this should be done for Major Arcana.
OTOH, this is a system that doesn't invent a lot of new rules, and converts spell for spell, point for point with the Sorcery system, so a lot of our work is done for us already. Hence the need to tune the Wizardry power modifier to be -15%, which I use below.

Icy Weapon (10pts +40% net modifiers = 14 pts Full Cost)

Adding time and energy cost. One level of Takes Extra Time gives us a two second casting time. 22 FP casting cost gets us the rest of the way to -80%. The points value of the spell is now 2 points. Minor Arcana, IQ/Easy. Any wizard can learn and cast it.

Awaken Computer (36pts +25% net modifiers = 45 pts Full Cost)

Let's start with energy this time. 15 energy casting cost is worth -75%. Five levels of casting time get us to 32 seconds of casting time, for a final cost of 8 points. Minor Arcana, IQ/VH. No prereqs other than being a wizard.

Remove Curse (50pts +30% net modifiers = 65 pts Full Cost)

Now let's add casting time and energy cost. Let's add three levels of Takes Extra Time; casting time is now 16 seconds. Then we'll get all the way to -80% by increasing the casting cost to 10 FP. This reduces the point cost of the Advantage to 10 points. Just barely a Major Arcana, but that does reduce its cost to 2 points.

You therefore need 1 level of Wizardry to cast this, and it requires an extra Ready action prior to beginning casting of the spell. Casting cost remains 10 FP. The spell itself is IQ/Easy.

I want to stress that this is off the top of my head as an example of how we might do it. It is not "done" or carefully thought out or even playtested. Despite the length.

To me the biggest advantage is that it's nearly all RAW and leverages Sorcery write-ups that we're likely to get anyway. At that point we have skill-based magic-as-knowledge Wizardry, Advantage-based magic-as-powers Sorcery, and freeform improvisational magic-as-creativity Ritual Path Magic. That hits most of the magical archetypes.
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Old 09-19-2015, 05:51 PM   #4
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Default Re: Alternate GURPS: converting Sorcery Spells into Magic Spells

Some thoughts and nitpicks:

First: the Unusual Training Perk in “From Skills to Advantages” strips out the skill's enabling advantages and prerequisites but imposes the equivalent of an Accessibility limitation on the resulting Advantage; to truly run it backward, you ought to require the builder of the original spell to incorporate an Accessibility limitation that's going to be stripped out when converting the Ability to a Skill (in exchange for the skill being classified as “cinematic”, requiring some sort of enabling Advantage such as Trained By a Master or Magery, and possibly acquiring a prerequisite chain). This is going to feel odd, though, since you won't actually have to specify the nature of the Accessibility restriction, seeing as how its effects are going to be stripped out. If you go this route, you should probably standardize the discount provided by this “phantom limitation” — say, at -20%?

Second: if you place a requirement that every spell's “ability build” must come in between 4–9 points (for a Minor Arcana spell) or 16–45 points (for a Major Arcana spell) after modifiers, and change the -80% in limitations from a mandate to a suggestion (to give the spell designer some flexibility in hitting these ranges), you will never have an Easy or Average skill. Of course, you won't be able to convert all existing Sorcery Skill builds over with this, as some of them will “fall into the gaps”. You can resolve this with a minimum of trouble by saying that a build that falls in the 2–3 range (for Minor Arcana spells) or 10–15 points (for Major Arcana spells) without adjustments to energy cost or casting time count as Average or Easy Skills.

Third: what does Wizardry do, other than serve as a point buffer for Major Arcana spells to alt off of? Divine Power grants access to freeform Prayers; Sorcerous Empowerment grants “default access” to low-level Spells. Wizardry doesn't appear to do anything other than enable spell use.

Finally, I wouldn't worry about spell builds that are based off of Advantages totaling over 225 points before modifiers. There really aren't all that many of them; so until I see one that strikes me as a reasonable spell, I'd be fine with just forbidding them. That said, the notions you explore there could potentially be developed as an alternative to the “Major Arcana” concept you’re introducing as a way to build spells off of Advantages costing more than 45 points before modifiers.
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Old 09-19-2015, 11:25 PM   #5
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Default Re: Alternate GURPS: converting Sorcery Spells into Magic Spells

Quote:
Originally Posted by wellspring View Post
Icy Weapon (10pts +40% net modifiers = 14 pts Full Cost)

Adding time and energy cost. One level of Takes Extra Time gives us a two second casting time. 22 FP casting cost gets us the rest of the way to -80%. The points value of the spell is now 2 points. Minor Arcana, IQ/Easy. Any wizard can learn and cast it.
Any system that makes Icy Weapon cost 22 FP to cast is not one I would like to deal with. Basically, spells you can expect a wizard to cast on his own are those costing about 1, about 4, or about 10. 20-30 is the range of "break out the powerstone unless you're a greater archmage with a huge energy reserve" and 50+ is "This is meant to be cast ceremonially, but we put non-ceremonial casting times here so you know what one tenth of the actual casting time is".

I personally consider any spell with a cost greater than 20 unuseable.
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Old 09-20-2015, 10:18 AM   #6
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Default Re: Alternate GURPS: converting Sorcery Spells into Magic Spells

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Originally Posted by simply Nathan View Post
...
I personally consider any spell with a cost greater than 20 unuseable.
First: I completely agree with Nathan, and for this reason, IMO, this project needs new rules.

Second: Why would any spell cost more than 16 FP? (16*-5%=-80%)
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Old 09-20-2015, 10:31 AM   #7
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Default Re: Alternate GURPS: converting Sorcery Spells into Magic Spells

Agreed. Let's try reworking Icy Weapon as a Hard skill instead of an Easy one: we need -90% worth of time-and-cost Limitations to bring 10 + 40% down to 10 - 50%. This would shave 6 points off of the energy cost that wellspring came up with. If my comments about a “phantom Accessibility limitation” hold true, the -20% contributed by that removes the need for another 4 energy points. That's still a 12-point activation cost, which is rather steep. Every doubling of the activation time knocks off two energy; so we could go with 12 energy and 2 seconds, 10 energy and 4 seconds, 8 energy and 8 seconds, etc. I think 4 seconds is the longest activation time we can tolerate; so we're looking at 10 energy and 4 seconds. Still pricy, and now verging on being too slow.
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Old 09-20-2015, 10:59 AM   #8
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Default Re: Alternate GURPS: converting Sorcery Spells into Magic Spells

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Originally Posted by Lia Valenth View Post
Why would any spell cost more than 16 FP? (16*-5%=-80%)
You're forgetting that limitations first cancel enhancements.
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Old 09-20-2015, 11:02 AM   #9
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Default Re: Alternate GURPS: converting Sorcery Spells into Magic Spells

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You're forgetting that limitations first cancel enhancements.
...yes, yes I am.
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Old 09-20-2015, 04:38 PM   #10
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Default Re: Alternate GURPS: converting Sorcery Spells into Magic Spells

Quote:
Originally Posted by dataweaver View Post
Some thoughts and nitpicks:
Thanks so much for the detailed reply! Like I said, it was all off the top of my head, written more or less without revision just to get things rolling.

Quote:
Originally Posted by dataweaver View Post
First: the Unusual Training Perk in “From Skills to Advantages” strips out the skill's enabling advantages and prerequisites but imposes the equivalent of an Accessibility limitation on the resulting Advantage;
I was thinking that this is where I'd re-insert the spell prerequisite chains later. But you're right that I removed a phantom perk that, as currently written, wouldn't have been needed.

Quote:
Originally Posted by dataweaver View Post
Second: if you place a requirement that every spell's “ability build” must come in between 4–9 points (for a Minor Arcana spell) or 16–45 points (for a Major Arcana spell) after modifiers, and change the -80% in limitations from a mandate to a suggestion (to give the spell designer some flexibility in hitting these ranges), you will never have an Easy or Average skill.
Good idea. Of course if the disadvantage level is merely a suggestion, then at that point you can simply mandate that the final advantage falls into one of those two ranges. OR players can use Link or something to add a functional special effect.

Quote:
Originally Posted by dataweaver View Post
Third: what does Wizardry do, other than serve as a point buffer for Major Arcana spells to alt off of? Divine Power grants access to freeform Prayers; Sorcerous Empowerment grants “default access” to low-level Spells. Wizardry doesn't appear to do anything other than enable spell use.
Nothing yet. You're exactly right, that's my plan. It's purely TBD, but I had Sense Magic in mind for the similarity to Magery. You'd still have Hard Core Improvisation, at least by my read of Powers and alternate abilities.

Quote:
Originally Posted by dataweaver View Post
Finally, I wouldn't worry about spell builds that are based off of Advantages totaling over 225 points before modifiers. There really aren't all that many of them; so until I see one that strikes me as a reasonable spell, I'd be fine with just forbidding them. That said, the notions you explore there could potentially be developed as an alternative to the “Major Arcana” concept you’re introducing as a way to build spells off of Advantages costing more than 45 points before modifiers.
That was exactly my thought.

Like I said, this is very much a spontaneous idea that popped out, something to start a conversation rather than a proposal. So I appreciate the detailed suggestions.
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