Let's make some examples of how long a average fight takes with different stats.
AC 16 was calculated as the average AC of mobs in keep on the shadowfell.
I am assuming 25 hp pr monster
I am assuming that one PC has one monster to kill every level N combat.
I am assuming no feats that increase damage/to-hit for any of the characters
14 stat longsword = +5 to hit or 50% hit chance, 1d8+2 damage or 6.5 avg, avg damage per attack = 3.25, average rounds = 25/3.25 = 7.7 rounds
16 stat longsword = +6 to hit or 55% hit chance, 1d8+3 damage or 7.5 avg, avg damage per attack = 4.1, average rounds = 25/4.1 = 6.1 rounds
18 stat longsword = +7 to hit or 60% hit chance, 1d8+4 damage or 8.5 avg, avg damage per attack = 5.1, average rounds = 25/5.1 = 4.9 rounds
20 stat longsword = +8 to hit or 65% hit chance, 1d8+5 damage or 9.5 avg, avg damage per attack = 5.1, average rounds = 25/6.1 = 4.1 rounds
A fight with a 14 stat character lasts more than 50% as long as a fight with a 18 stat character and nearly 100% longer than a fight with a 20 stat character.
Apologies in advance but if anyone tried to show me the above before I had started playing D&D I would have run a mile. I understand that to play the game you need to kill some bad guys but it's a roleplaying game first and foremost, regardless of edition.
Are you saying that a 14 for prime stat is a bad thing- shouldn't be done, or are you saying... look at the consequences, the fights (subject to the law of averages) are going to take longer, if so- who really cares as long as people are having fun.
I don't want to sound too caustic (if at all), I love the maths but I just don't understand what the problem is.
Is a score of 14 for Int on one PC preventing people from playing a game and having a laugh doing so...
Sorry again, but all this just reads like madness, I don't recognise the game described in some of the posts above, or else barely.
PS My most memorable character (when I was a player) AD&D I think was generated with roll 4d6 take best three and his highest stat was a 15, multi-classed Cleric/Wizard/Rogue- I think. He memorised no offensive spells (ever) and would generally get through things by being much smarter than the average goblin/kobold/bugbear/mind flayer; or else by having a no-necked brainless lug do all his fighting for him. When the no-necks needed someone to charm the pants off the Jarl then I was the go-to guy, same with healing- the price for which was keeping me safe, same for finding the traps etc...
My brother played Boron the Illusionist in the same party- we still laugh and tell tales about him to this day (over twenty years later- we don't remember any of the 'optimised' characters with their 18 Str & 18 Con). Other than a high Int his stats were all below 10 (that's how it was back then with us), and we rolled our HP and 1's counted. Boron was utterly crap, and yet made something like 8th level before the joke wore thin. He famously hid under a cart full of the parties treasure (that's also how we were back then) while a Red Dragon attacked him, just him- the rest of the party were battling the Red Dragons twin elsewhere. Boron saved every time- got out from the incinerated cart, robes on fire- Dragon swoops around for next pass, and flings his dagger- natural 20- roll crit to confirm, natural 20 again- roll on DMs own designed crit table 00- instant death.
Illusionist Level 8, wearing purple robes, loon pants, gold curly-up slippers and armed with a +1 Dagger flings said dagger and slays Red Dragon...
You figure the odds.
That's why I play- not for the one in a million chance but because it's a fantasy game, and your characters can do/try anything.
My point, and apologies if I'm picking on you- I'm not, the game gets played a thousand different ways by a thousand different people, the result- killing the monsters, solving the puzzle, getting the girl whatever is important, but the journey, the journey is everything.