Luck (Spellcasting only) - how to value limitation

[primanator]

I have a player that wants the Luck advantage, usable just for spellcasting. I find it rather powerful still, especially with Blocking spells being almost un-failable (if that is even a word).
I am thinking -30 to -40%. What say the hivemind?

[sir_pudding]

Seems to be a fairly straightforward application of Aspected, pretty much equivalent to Aspected:Combat, and should have the same value.

[primanator]

OK - it seems obvious, but rather harsh. I'll stick with it though. Thank you!

[Peter Knutsen]

Originally Posted by sir_pudding

Seems to be a fairly straightforward application of Aspected, pretty much equivalent to Aspected:Combat, and should have the same value.

Yes, it is straightforward.

I don't like that Aspected is only -20% in general, but that's what the RAW says, and for All Of Spellcasting it's not overly expensive.

[Not another shrubbery]

Originally Posted by Peter Knutsen

I don't like that Aspected is only -20% in general, but that's what the RAW says, and for All Of Spellcasting it's not overly expensive.

It should not be a big deal to adjust the limitation to fit the class, but the usual assumption would be to make sure the class fit that value.

[Peter Knutsen]

Originally Posted by Not another shrubbery

It should not be a big deal to adjust the limitation to fit the class, but the usual assumption would be to make sure the class fit that value.

The RAW makes no such provision. The RAW says -20%. Period.

[Kax]

I will make the point that it explicitly states in the Magic rules that Luck can't be used on spells. I'd add +100% to any modifier you come up with due to that.
If he wants to avoid crit fails, use the Mitigating Skill perk.

[Not another shrubbery]

Originally Posted by Kax

I will make the point that it explicitly states in the Magic rules that Luck can't be used on spells. I'd add +100% to any modifier you come up with due to that.

It can't be used for Ceremonial Magic. Normal spellcasting seems to allow for it, although Thaumatology notes (on p30) that Luck does not apply to effects tables rolls, such as the Critical Spell Failure Table. If your spell critically fails despite your Luck, you'll just have to live with whatever the result on that roll dictates.

[starslayer]

Originally Posted by Kax

I will make the point that it explicitly states in the Magic rules that Luck can't be used on spells. I'd add +100% to any modifier you come up with due to that.
If he wants to avoid crit fails, use the Mitigating Skill perk.

incorrect.

Originally Posted by GURPS magic

Ceremonial magic may not be assisted with
Wishes, Luck, or Bless spells. In general, magic cannot
affect or predict the outcome of a ceremonial ritual.

All other spells can happily benefit from the luck advantage. Further, this is pretty much a cantonal application of 'cosmic: One rule exemption+50%' if someone STILL wanted to be able to apply luck to ceremonial use. (Of note super luck is not covered, so someone with super luck can still dictate one critical success at spell-casting/game, ceremonial or not).

Further I have at least always believed that that reference was to Luck the potion (presented later in the GURPS magic book), rather then Luck the advantage (presented in the basic set)- so if you have luck the advantage (and it does not have a -10% magic modifier) you can use it on cerimonial magic without incident, but if you consume a potion of Luck to get the luck advantage, you cannot (because the potion of Luck grants Luck[-10% magical])

[Lamech]

Indeed, I also think the "Luck" refers to Luck the potion, not Luck the advantage. Its not entirely clear, but the fact that the next thing it says is "in general magic" seems to imply pretty heavily that they mean the magic potion. I think the idea is to prevent a mass cerimonial magic spam.