Luck, Spending Luck, and POW in CoC / BRP

[Myrmidont]

Got a question about the CoC Luck stat and Spending Luck optional mechanic. In BRP, Luck is POW score x5 (although Fate Points metacurrency runs on straight POW score). However in CoC, Luck is a completely independent stat.

Does anyone know the rationale behind why Luck and POW are separated in CoC? Yet the equivalent mechanic in BRP does run on POW.

Could you not just cut the Luck characteristic, and say your Luck Pool is POW x 5?

I'm just thinking that if Luck ran off POWx5, then it would give characters who don't know Mythos spells something else to use their POW for. And the characters who do know spells, have something better than luck to rely on - actual magic. 

Edited July 17 by Myrmidont
clarification

[Warthur]

My assumption is that linking Luck and POW implies that good fortune is a predictor of spiritual potence. In a more benign cosmos, that might be the case, but in Call of Cthulhu... less so.

[Myrmidont]

So if I wanted to run CoC adventures using more of the core BRP:UGE mechanics, I should add in a Luck Characteristic to BRP?

[SDLeary]

51 minutes ago, Myrmidont said:

So if I wanted to run CoC adventures using more of the core BRP:UGE mechanics, I should add in a Luck Characteristic to BRP?

You don't really need to... editions before the current one worked without Luck as a separate thing. If you plan on using mostly 7e materials it might be helpful, one less thing you have to change/ignore in the individual resources.

SDLeary

[EldorfDragonsbane]

I like having luck as a separate score. You could have a character with a real high POW score but low Luck score or a low POW score and a high Luck score. Think of it this way just because John Doe had a POW of 90 and 18 MP doesnt mean he is going to be a individual with a lot of luck. He might be starting off with 30 luck points and that has to last him though the scenario, does he burn it to improve a roll or two or keep it in case he has to make a luck roll? Or how about Bill Blank he is a character with a low POW score of 40 but his luck is 75, with that 75 luck he has more opportunity to pass that luck roll to see if there's rope in the trunk/boot of the car that he just stole to pull John Doe out of the pit he fell into, or he might spend an 15 luck points to turn that failed locksmith roll into a success so he can pick the lock and escape the cage Cultist Craig locked him in, which in this case spending that 15 points of luck isn't as big of an issue as it would have been for John Doe if he had to spend those 15 points.

 

Now when it comes to learing and casting spells, John has the advantage both in MP and in SAN, a spell that requires say 5 MP and cost 3 SAN is less of an impact to him then it would be to Bill (John goes from 18 MP to 13MP and SAN 90 to SAN 87 when Bill goes from 8 MP to 3MP and 40 SAN to 37 SAN, for this example we are going to assume both John and Bill have their full starting MP and SAN, though in all likely hood they wouldn't have the full starting SAN). Here as you can see while John doesn't have the luck that Bill had he does have the advantage of the better MP and SAN, to me this helps offset the fact he isn't as "lucky" as his buddy Bill.