Generating and using the Luck stat from S.P.E.C.I.A.L.

[Theodoxus]

I'm sure I'm late to the party when it comes to Fallout, the video game. I knew a bit (and played the original Wasteland as a kid, a LOT), but didn't really know about the stats system used until I started watching the series. I've always been a fan of anagrams and acronyms, and I was in shock when I learned what S.P.E.C.I.A.L. meant.

Now, since each attribute maps to a D&D attribute, either directly (Strength, Intelligence), or comparatively (Dexterity -> Agility, Wisdom -> Perception), it makes sense that they could be used for D&D... well, except for that elusive Luck stat.

So, I'm here to see if what I'm planning to do with it, would work, with folks around here being all brainy and whatnot.
*Note, I'm not using the Fallout version of base 5 with 5 points to spend, this is the standard 4d6dL of 5th Ed D&D)

If we map the 6 attribute modifiers for D&D to SPECIAL, you get:

Strength (Strength)
Perception (Wisdom)
Endurance (Constitution)
Charisma (Charisma)
Intelligence (Intelligence)
Agility (Dexterity)

What I'm thinking of doing is adding the attribute modifiers together, to generate a whole number that equals your Luck pool.

So, if your attributes and mods were:

S: 16 (+3)
P: 10 (+0)
E: 14 (+2)
C: 8 (-1)
I: 15 (+2)
A: 14 (+2)

Your Luck pool would be 3+0+2-1+2+2=8

So, what does a Luck pool do? It allows you to add up to your current pool amount, to any d20 roll you make. So, with 8 points, you might add 2 to an attack roll, reducing your pool to 6. You might then add 4 to a saving throw, leaving 2. Then add those two to a skill check later on.

Luck would then restore the full pool on a short rest.

I could see a couple additional options. Perhaps spend 5 Luck to make a roll with advantage (or burn 5 Luck to force an enemy to roll with disadvantage) akin to a Paladin Lay on Hands granting different forms of healing for 5 points. In this regard, I'd turn the Lucky feat into a bonus pool of 15 Luck points, which still allows for their use to create advantage, but also to tip a miss into a hit, or a failed save into a made one.

The only lingering question I have is how to determine when you can use the pool. I'm thinking after the roll is made and the result is known, so you can 'push Luck' into a success (or force a reroll for disadvantage just before an attack hits). This is obviously a bit more powerful than 'after the roll, but before the result', but that doesn't feel like luck, but a gamble. Closely related, but not the same. Also, even with a short rest recharge, the pool won't be so large that Luck can be used willy-nilly.

Thoughts?

[Notafish]

In the system you describe, I would also want to know how much "luck" I would need to spend to push a failure into a success. It doesn't feel quite as "lucky" to me as the rerolls from the Lucky feat (luck and gambling do go together as concepts for me), but I think I would have fun with the system.

In point buy, most characters would have close to the same amount of luck, right? Vanila PHB human could make out pretty well, though.

[clash]

I like the way it rewards classes that are naturally more MAD. Classes like monk and barbarian would end up with more luck because of pushing more stats higher for their class which is a good balancing factor. However, it creates a kinda odd paradox where classes like rogue that fit the luck theme better are more SAD and would likely have lower luck.