Oh, what the hell. I'll bite.
First off, I've decided that I'm just not that much of a fan of point allocation systems, for reasons I think I've talked about earlier. I like the randomness that comes with rolling. With point allocation systems, there's always going to be a small set of optimal allocations for each class. And I think that low stats are more fun when they came up as the result of a roll instead of just being "dump stats."
For your method in particular, I'd be reticent to allow players to choose attributes as low as 3. I'm not sure where I'd set the lower bound—probably somewhere between 6 and 8—but low stats never seem to hurt as much as high stats help. It's probably a combination of strategic dump-statting and DM kindness in not making PCs
really play their 3 charisma (a true 3 CHA PC would not be fun to be with, for example, and a 3 INT PC would need help putting his own armor on).
I'm not sure that the optimal min/max build is 18, 18, 16, 16, 3, 3. Few classes can really benefit from having four stats over 16. Mostly, it's the classes that have non-primary attribute requirements (druids and paladins with their charisma requirements, for example). Everyone can use good CON and DEX scores, and then it's pick your prime attribute. So you could do (18, 10, 9) (15, 15, 7). One sorta-bad score, two blah, and a couple that will get you +1 to CON and DEX, with no real penalty to the other scores.
In fact, let's look at the ways to allocate 37 points among 3 scores. Here are all the possibilities (I think):
(18, 16, 3), (18, 15, 4), (18, 14, 5), (18, 13, 6), (18, 12, 7), (18, 11, 8), (18, 10, 9),
(17, 17, 3), (17, 16, 4), (17, 15, 5), (17, 14, 6), (17, 13, 7), (17, 12, 8), (17, 11, 9), (17, 10, 10),
(16, 16, 5), (16, 15, 6), (16, 14, 7), (16, 13, 8), (16, 12, 9), (16, 11, 10),
(15, 15, 7), (15, 14, 8), (15, 13, 9), (15, 12, 10), (15, 11, 11)
(14, 14, 9), (14, 13, 10), (14, 12, 11)
(13, 13, 11), (13, 12, 12)
When looking at these sets, it's worth keeping in mind that some scores are just as good as others or have only minor differences, depending on the attribute:
- STR: 8-13 (ignoring 100 lbs worth of carrying capacity and a small BB/LG difference)
INT: **
WIS: 8-14
DEX: 7-14
CON: 7-14 (ignoring SS/RS)
CHA: 9-12
This ignores AD&D1e things like minimum attributes for certain races and classes. INT is weird in that there is no "middle range" where all scores are the same, at least if you care about the languages known. OTOH, if you aren't a mage and don't care about number of languages known, an INT of 3 isn't mechanically much worse than an INT of 18.
So if you're going to have a wisdom of 14 or less, for example, you might as well have a wisdom of 8 and use those other 6 points where they'd make a difference (assuming you're not a cleric, which is a safe assumption if you're considering a wisdom of 14). If you're thinking of having a dexterity of 14, you might as well make it a 7—you won't be any worse off (this all assumes that a DM doesn't like to use attribute check rolls).
Keeping that in mind, there are some attribute sets in the list above that are clearly better than others:
- if you're only going to have one stat in the three that gives a bonus, you're probably going to use (18, 11, 8) or (18, 10, 9) (or maybe (18,12,7)). Except in weird circumstances (e.g., where bumping STR or CHR to 14 is worth taking a penalty to another stat, which will almost never happen), these are all strictly better than (18, 13, 6), (18, 14, 5), (17, 14, 6), (17, 13, 7), (17, 12, 8), (17, 11, 9), (17, 10, 10), (16, 14, 7), (16, 13, 8), (16, 12, 9), (16, 10, 10), (15, 13, 9), (15, 12, 10), (15, 12, 11), (14, 14, 9), (14, 13, 10), (14, 12, 11), (13, 13, 11), and (13, 12, 12).
- (15, 15, 7) gets you two stats with (mild) bonuses without taking penalties.
- After that, you get the big trade-off score sets. You can get two scores with bonuses in exchange for one really low score. Here's where min-maxing and dump stats start to get to be a real issue: (18, 16, 3), (18, 15, 4), (17, 17, 3), (17, 16, 4), (17, 15, 5), (16, 16, 5), and (16, 15, 6). Here, it's all about tradeoffs between bonuses and penalties.
Note that if you don't allow choosing stats below 8, the allocation becomes simple: it's probably some combination of (18, 11, 8) and (18, 10, 9). If you allow stats as low as 7, you can add (15, 15, 7) into the mix.
My guess is you'd get a lot of PCs with two 18s and a bunch of safe middle stats, or 18, 15, 15, and some safe stats, and then some minmaxing of bonuses and penalties. (18, 17, 16, 10, 9, 4) would be one fairly powerful set, depending on the dump stat, as would (17, 16, 17, 16, 4, 4).
So...yeah. It's an interesting idea, but I'm not sure I'm on board with this method. To make it workable, I think you'd need to make sure the penalties hurt, or put a limit on the number of scores < 8 that a person could choose.