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Old 05-30-2012, 08:00 AM   #1
Anders
 
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Default Different critical spell failure tables

I've been thinking about critical spell failure tables and want to toss out two ideas.

One is the idea of giving different traditions of mages different tables - this is implicit in the Dark Magic perk but this would apply to everyone.

The second idea is to vary table by area. So down in the valleys you have the standard table, but up on the faux-celtic Highlands you use another table.

Has anyone tried to do something like this?
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Old 05-30-2012, 08:10 AM   #2
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Default Re: Different critical spell failure tables

Never done it by location but have done one by college and tradition.
Fair amount of work and the players didn't really get much out of it.
You could also just go ahead and improvise results based on the roll.
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Old 05-30-2012, 09:09 AM   #3
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Default Re: Different critical spell failure tables

Thaumatology has several different tables.
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Old 05-30-2012, 09:26 AM   #4
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Default Re: Different critical spell failure tables

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Originally Posted by Refplace View Post
Fair amount of work and the players didn't really get much out of it.
This is the real crux of the design issue here. Crit fails are pretty rare, rarer still for those with Luck.

It'd be a lot of work to produce a number of results that actually feel different from one another, especially if you have to make each result meaningful due to the potential rarity of their occurrence. The rarity is made even worse if limited to locations, as some locations might harder ever be visited!

An alternative is to have only a handful of results produce "special" outcomes, perhaps all the extreme crit fails are the same due to the nature of magic, but minor failures are a lot more stylised. This would both cut down on the work required in making full lists of outcomes, and allow some harmony in outcome which would make magic more predictable and leave no nasty shocks in failing somewhere as yet unvisited.

As for different fails for different traditions of mages, then yeah Thaumatology has a number of tables with different themes which fit more for differently styled/college focused mages.
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Old 05-30-2012, 09:38 AM   #5
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Default Re: Different critical spell failure tables

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You could also just go ahead and improvise results based on the roll.
That's I believe the actual baseline assumption, and the table is for "inspiration". GURPS Basic set, 235: "On a critical failure, you must spend the full energy cost and the spell fails . . . badly! The GM may use the Critical Spell Failure Table or improvise some other “backfire” he finds amusing."
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Old 05-30-2012, 09:44 AM   #6
Peter Knutsen
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Default Re: Different critical spell failure tables

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Originally Posted by Asta Kask View Post
I've been thinking about critical spell failure tables and want to toss out two ideas.

One is the idea of giving different traditions of mages different tables - this is implicit in the Dark Magic perk but this would apply to everyone.

The second idea is to vary table by area. So down in the valleys you have the standard table, but up on the faux-celtic Highlands you use another table.
One thing you should seriously consider, if you do this, is to make critical failure tables that can take modifiers. The current ones, in GURPS Magic and GURPs Thaumatology, are 3d6-based with the worst outcomes occuring both on very low and very high rolls.

This means that there is no conceptual room to have any kind of effect, such as from an advantage or perk, or an enchantment, or a casting decision (such as to cast very slowly and carefully), that modifies the critical failure result roll.

And of course you can modify the probably too extreme mana level rules, which IIRC say that in a sufficiently high mana area, all casting failures are critical failures. Once you have a table that can take modifiers, the effect of mana above a certain level can simply be a +5 or +10 modifier to the table roll, so that on average the consequences are nastier.

Likewise, casting in too low mana can also have nastier consequences. Or you could have a separate table for too-low-mana that has consequences that are as nasty as the normal table, but they're all very subtle results, avoiding blatant observable consequence that threatens the low-mana ambience that you presumably want.

The only thing you can do is to allow X rolls, where X is 2 or 3 or in extreme cases 4, and then letting the player (or the GM, if it is an NPC casting) choose the preferred result, based on the assumption that the choice will tend strongly towards the less severe effects around the middle of the 3d6 table.

You could go with a 1d12 or 1d18 or 1d36 table, based on the assumption that you don't want to use dice with other than six sides, but keeping in mind that modifiers to such a table roll can be both positive and negative, you'd need to start the table at a negative value, e.g. -2 or -3, and end it at some point above the maximum roll outcome, e.g. 41 or 45 for an 1d36-based table.
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Old 05-30-2012, 09:45 AM   #7
Peter Knutsen
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Default Re: Different critical spell failure tables

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Originally Posted by PseudoFenton View Post
This is the real crux of the design issue here. Crit fails are pretty rare, rarer still for those with Luck.
Isn't it 2% of rolls, without Luck?

That's pretty damn often!
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Old 05-30-2012, 10:06 AM   #8
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Default Re: Different critical spell failure tables

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Originally Posted by Peter Knutsen View Post
Isn't it 2% of rolls, without Luck?
Not if you have at least a 16 skill.
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Old 05-30-2012, 10:15 AM   #9
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Default Re: Different critical spell failure tables

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Originally Posted by Peter Knutsen View Post
Isn't it 2% of rolls, without Luck?

That's pretty damn often!
In theory? Maybe. In practice? No, not really. This'd be a case where probability|statistics are deceptive. The sample size is too small to be predictive.
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Old 05-30-2012, 10:18 AM   #10
Peter Knutsen
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Default Re: Different critical spell failure tables

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Never done it by location but have done one by college and tradition.
Fair amount of work and the players didn't really get much out of it.
You could also just go ahead and improvise results based on the roll.
The world is as it is because of the way magic works, including the likelihood of critical casting failures, and the variety of more or less likely outcomes of a critical failure that can occur.

The decisions of - at least - tens of thousands of NPCs are strongly influenced by this, both day-to-day decisions, and larger life decisions.

Social norms evolve, influenced in part by empirical knowledge of what can and can't happen, and how likely it is to happen.

For instance in those parts of my Ärth setting where spell magic is most common, the Keltic lands and the two civilized Caliphates, there is a custom that when you are about to cast a spell, you must make a warning gesture so that people can choose to step away from you if they so desire.

A casting Fumble cannot cause actual damage to bystanders. This is known to not be able to occur at all (a Fumbled roll on trying to activate a magic item ability, however, can lead to a dangerous explosion - two different but related kinds of magic). Most Fumbles affect the caster himself, maybe with a temporary penalty to further casting (sometimes in the form of Noise, astral turbulence that can be calmed quickly with meditation, but which will dissipate naturally over time), or a temporary or permanent loss of the ability to cast spells from one "College" or a themed group of "Colleges", or even all spells, or rapid aging.

The reason people may choose to step some distance away is that sometimes Fumbles do affect one bystander, and this being more likely the closer the bystander is to the caster. One effect has a range of 4 meters, another rarer one of 6 meters. There may be a super duper rare one with a range of 8 or 10 meters (50% chance of either) but if so it is so unlikely to occur (much less than once in a billion rolls) that it may never have occured as of the present world time (late 10th century), and so is the subject of controversial speculation.

These, the so-called Fumble Lash-Outs are not physically dangerous, but can cause cosmetic changes such as a hair or eye colour or sex change, usually into something naturally occuring (a natural pigmentation for the race, or at least for the species), but sometimes not (e.g. blue hair), or in rarer cases a species change (figuring out an objective way to randomly determine the species, while at the same time achieving great variety, is a bit of a challenge!), and in rarer cases still a species hybridization. These effects usually last for some hours or days, in rare cases longer, sometimes very long (years, possibly decades), or are permanent. The longer the rolled duration, the harder they are to revert prematurely.

One NPC once turned his cat familiar into a human-cat hybrid with a Fumble Lash-Out, and that has ended up as a significant element of his backstory.

Another NPC, somewhat overconfident (in his youth - he has since outgrown that), permanently lost his ability to cast spells from the Shadow "College", due to an avoidable Fumble (a spell that he tried to cast in a way he didn't have to). Since Shadow spells were and still are highly useful for him, as a spy and agent (complementing his main speciality of Illusion spells nicely), he ended up spending part of his non-renewable magical resources (Essence) on creating a magical item that can reproduce a few of the most useful Shadow spells.

All that is possible only because the magic systems of Ärth are known and well defined. In advance. You cannot have that with an ad hoc anything-goes approach.

Rules aren't only for player characters. Rules are for worlds. The world is the rules.
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