Converting Shadowrun Magic to GURPS

[Jürgen Hubert]

Shadowrun has a great setting marred to a succession of frequently frustrating game systems. Therefore, I've always been tempted to simply port it over to GURPS - but considering the complexity of the system and the setting, this is not a trivial task.

For the purpose of this thread, I'd like to focus on the magic of Shadowrun. I don't necessarily want to do a 1:1 conversion of every magical power, but I do want to get the general flavor right.

Let's start with spell-based magic, leaving things like Initiation, adepts, metamagic, different schools of magic and so forth for later. Before we tackle individual spells, I'd like to establish a list of the general "rules" of Shadowrun spells.

- Each spell costs the same effort to learn, and there are no prerequisites.

- Spells are primarily balanced by how fatiguing they are.

- Spells can be cast at different "Force" levels. The higher the Force, the more potent the effect - but the more fatiguing the spell will end up being.

- More skilled spellcasters will be able to generate more powerful effects even with the same Force.

- More potent spellcasters will generate more powerful effects, and their potency determines whether the spell is merely fatiguing or actively damages them.

- Low-Force spells are hard to detect, while high-Force spells are easy to detect.

- Strong-willed spellcasters will end up being less fatigued by spells than weak-willed ones.

- Apart from ritual magic (a topic for later), spells are cast instantaneously (i.e. a single "Concentrate" action). The only exceptions are spells which cause a permanent physical alteration.

- For permanent physical alterations which are not directly damaging, artificial objects are harder to change than simple, "natural" objects. Cybernetic and other implants count as "artificial" and make it more difficult to cast such spells (such as healing spells) on their owners.

- Spell ranges are Self, Touch, or Line of Sight (meaning purely optical Line of Sight). Detection spells can also have a range of tens or hundreds of meters. For area effects, the radius will be determined by the spell's Force.

- Spells that affect both living creatures and unliving objects are more fatiguing than spells that merely affect living creatures.



What are your thoughts so far?

[Diomedes]

Originally Posted by Jürgen Hubert

- Each spell costs the same effort to learn, and there are no prerequisites.

Sounds like you should start with standard magic, and ignore prerequisites.

Originally Posted by Jürgen Hubert

- Spells are primarily balanced by how fatiguing they are.

- Spells can be cast at different "Force" levels. The higher the Force, the more potent the effect - but the more fatiguing the spell will end up being.

- More skilled spellcasters will be able to generate more powerful effects even with the same Force.

Already part of the standard system, including energy dissents for high skill.

Originally Posted by Jürgen Hubert

- More potent spellcasters will generate more powerful effects, and their potency determines whether the spell is merely fatiguing or actively damages them.

The "using HP instead of FP rules?"

Originally Posted by Jürgen Hubert

- Low-Force spells are hard to detect, while high-Force spells are easy to detect.

So any detection ability or spell will take a modifier based on the energy in the spell being detected.

Originally Posted by Jürgen Hubert

- Strong-willed spellcasters will end up being less fatigued by spells than weak-willed ones.

You could let high Will provide an additional energy discount, or let mages buy an Energy Reserve based capped/based on their Will.

Originally Posted by Jürgen Hubert

- Apart from ritual magic (a topic for later), spells are cast instantaneously (i.e. a single "Concentrate" action). The only exceptions are spells which cause a permanent physical alteration.

Any spells in the setting are defined as having a one-second casting time.

Originally Posted by Jürgen Hubert

- For permanent physical alterations which are not directly damaging, artificial objects are harder to change than simple, "natural" objects. Cybernetic and other implants count as "artificial" and make it more difficult to cast such spells (such as healing spells) on their owners.

An appropriate penalty to cast. Cybernetics include free Magic Resistance.

Originally Posted by Jürgen Hubert

- Spell ranges are Self, Touch, or Line of Sight (meaning purely optical Line of Sight). Detection spells can also have a range of tens or hundreds of meters. For area effects, the radius will be determined by the spell's Force.

A setting switch, I'd say.

Originally Posted by Jürgen Hubert

- Spells that affect both living creatures and unliving objects are more fatiguing than spells that merely affect living creatures.

Defined in the spells themselves, more energy to affect both living and unliving targets.

[Jürgen Hubert]

Well, let me pick an example what I want - combat spells.

Basically, start with some variant of Innate attack for representing a "default" version of the spell. Figure out the CP cost, and then convert that into a fatigue cost according to some formula - basically, the more "tricked out" the spell is, the more fatigue it will cost instead of CP.

[Crakkerjakk]

Mages are already going to be super expensive. I would strongly advise against doing magic as powers unless you want 350 points to be a baseline runner or something.

I'll run through your original post in depth later today.

EDIT: I misunderstood what you were saying. I agree with Diomedes that adjustable spells would work for this. Or any of the general guidelines from improvisational magic for cost of effects in Thaumatology.

[Diomedes]

Originally Posted by Jürgen Hubert

Well, let me pick an example what I want - combat spells.

Basically, start with some variant of Innate attack for representing a "default" version of the spell. Figure out the CP cost, and then convert that into a fatigue cost according to some formula - basically, the more "tricked out" the spell is, the more fatigue it will cost instead of CP.

The Adjustable Spells from Thaumatology would work well here. Define a basic attack, and then declare a given percentage of enhancement to add an energy point to the spell's cost.

[Crakkerjakk]

Originally Posted by Jürgen Hubert

I don't necessarily want to do a 1:1 conversion of every magical power, but I do want to get the general flavor right.

I think this is key.

Originally Posted by Jürgen Hubert

Before we tackle individual spells, I'd like to establish a list of the general "rules" of Shadowrun spells.

Keeping with your above point, the question is how many of these are about flavor, as opposed to how the game system has done it?

Originally Posted by Jürgen Hubert

- Each spell costs the same effort to learn, and there are no prerequisites.

Meh. I think this is mechanically how it works. Not sure it's all that essential that Power Bolt be an entirely different thing from Power Ball to keep that SR flavor.

Originally Posted by Jürgen Hubert

- Spells are primarily balanced by how fatiguing they are.

Yeah.

Originally Posted by Jürgen Hubert

- Spells can be cast at different "Force" levels. The higher the Force, the more potent the effect - but the more fatiguing the spell will end up being.

Agreed this is pretty core.

Originally Posted by Jürgen Hubert

- More skilled spellcasters will be able to generate more powerful effects even with the same Force.

I'd quibble about "powerful," saying maybe that they are more precise or effective. But "it's not just about the Force of the spell," sure.

Originally Posted by Jürgen Hubert

- More potent spellcasters will generate more powerful effects, and their potency determines whether the spell is merely fatiguing or actively damages them.

Agreed.

Originally Posted by Jürgen Hubert

- Low-Force spells are hard to detect, while high-Force spells are easy to detect.

Don't know if it's core, but I think it's easy to replicate and makes sense.

Originally Posted by Jürgen Hubert

- Strong-willed spellcasters will end up being less fatigued by spells than weak-willed ones.

Mmrph. Will elaborate later.

Originally Posted by Jürgen Hubert

- Apart from ritual magic (a topic for later), spells are cast instantaneously (i.e. a single "Concentrate" action). The only exceptions are spells which cause a permanent physical alteration.

Not sure this is really "core."

Originally Posted by Jürgen Hubert

- For permanent physical alterations which are not directly damaging, artificial objects are harder to change than simple, "natural" objects. Cybernetic and other implants count as "artificial" and make it more difficult to cast such spells (such as healing spells) on their owners.

Yeah, the nature/technology dichotomy is pretty important.

Originally Posted by Jürgen Hubert

- Spell ranges are Self, Touch, or Line of Sight (meaning purely optical Line of Sight). Detection spells can also have a range of tens or hundreds of meters. For area effects, the radius will be determined by the spell's Force.

I don't think this is core.

Originally Posted by Jürgen Hubert

- Spells that affect both living creatures and unliving objects are more fatiguing than spells that merely affect living creatures.

Agreed, core.

You use a couple different terms. Will. Potency. Power. Skill. I agree these are in core SR rules. I don't know if you want to port those over, or if they're really key to the "flavor." I mean, do you want to have a separate drain resistance roll that's based on Will? I think that's too clunky a mechanic to port over. If we're using gurps magic, Magery level translates to Magic attribute (determining HP vs FP spell cost). Skill translates to skill.

Anyway. I look forward to what you come up with.

[Anthony]

I wouldn't worry too much about being a mage being expensive; in most editions of the rules it's an A priority, which should be worth somewhere in the 100-200 point range based on the capabilities of street sams and physads.

[Jürgen Hubert]

Originally Posted by Crakkerjakk

I mean, do you want to have a separate drain resistance roll that's based on Will?

I'm still divided over that. Some people should have an easier time resisting drain than others, but basing everything on Will would probably be too unbalancing, unless you are okay with all PC mages running around with Will 20.


Some further thoughts on how to do the conversion:

I will largely go with the Shadowrun 5E rules, since they are the most recent and more flexible damage levels are easier to port than the four damage levels of Shadowrun 3E and earlier.

In Shadowrun 5E, an "average human" has 10 physical damage boxes. After that, he becomes "dying".

In GURPS, I will thus treat those 10 physical damage boxes as 20 hit points, with each box representing roughly 2 hit points.

For statistical analysis purposes, I will assume that each Shadowrun die equals 1/3 of a "hit", or success. Thus, an average human - with a value of "3" in all attributes - will have one hit on most resistance tests.

[Jürgen Hubert]

Another idea: The Force of a spell represents the maximum Margin of Success you can have on your relevant skill roll. This Margin of Success is relevant for the overall damage of combat spells, resisted rolls for illusion/mind control spells, and so forth.

If your actual Margin of Success is higher than the Force of your spell, then any additional points of Margin of Success reduce the fatigue cost/drain of the spell.

So if you want to "play it safe", cast the spell at a low Force rating and you will have very good chances of reducing the fatigue cost of the spell. But if you want to go all out, cast it at a high Force - but then some fatigue is almost guaranteed.

This also simplifies the success roll and the drain resistance roll into a single roll.

[Crakkerjakk]

Originally Posted by Anthony

I wouldn't worry too much about being a mage being expensive; in most editions of the rules it's an A priority, which should be worth somewhere in the 100-200 point range based on the capabilities of street sams and physads.

All depends on what point level you want the game to run at. Start there, then back calculate roughly how many points you want people to be able to allocate to their specialty. I'd eyeball it at 250-300. Action template, plus a little for race/cyber/magic, and those abilities probably cutting into the action template a little. Say 200 points in regular abilities and 100 points in cyber/magic/race.