Reading through ACKS, the first thing that struck me as odd (after the divine spell progression, having started D&D with BECMI rather than B/X!) is that class get different rates of proficiencies. I find it very odd that as you progress in your class some classes get better at stuff relevant to their class than others. Specifically weird are Mages, who study a lot, get the least proficiencies. So I decided to do class and general at the same rate for every class.
Further thinking made me decide to disconnect proficiencies from level and just do it as experience points. This also means that demi-human classes still get something (a little like the post level grades in BECMI) after they top out in level. So, based on the Fighter progression, I intend to use:
A character gets a General Proficiency at:
0 XP (starting) + Int bonus
and every 500,000XP from then on.
A character gets a Class Proficiency at
0 XP (starting)
and every 360,000 XP from then on.
I too severed Proficiency progression from class, they're one of the most interesting differentiation-points for me, and so I wanted more of them. I simply gave everyone a General Proficiency every even-numbered level, and a Class Proficiency every odd-numbered level. Haven't decided whether that progression stops/slows after 9th level.
I should probably add that in my game there's no need to balance mages against fighters, because there are no mages. In a more regular game, I'd be constraining the caster's choices more towards Knowledges, since you don't learn Survival from sitting around studying.
1. Fighters tend not to get many bonus proficiencies from INT. Ensuring they get a steady supply of class proficiencies helps make sure they have enough proficiency slots to take proficiencies for the end-game, like Command and Military Strategy, if they want.
2. Fighters get more proficiencies than other classes because they have historically been underpowered over the mid to end game relative to Mages. ACKS tackles this in several ways. One of them is through cleaving, another is the fighter damage bonus, and the last is increasing proficiencies.
3. The fact that Fighters get more proficiencies isn't intended to say that Mages aren't more learned, but rather that what Mages have to spend their time learning (spells) isn't the same as learning day to day skills or specialties.
4. By restricting Mage's class proficiencies, it makes the INT bonus more important, which is a subtle benefit to being smart.
5. A generous selection of proficiencies allows Fighters to have a tad more customization, which is arguably more needed than for the more intrinsically choice-laden spellcasters.
#3, #4, and #5 are not incredibly important, but #1 and #2 are relatively important. If you equalize proficiencies for all classes, I'd recommend giving Fighter-types a bonus proficiency somewhere along the line.
I think the point is that proficiencies are Feats and Skills mixed (in 3E speak) so it makes sense for the Fighter to have a bigger bite. However, to me, it makes more sense for a Mage to have more knowledge type skills, but a lot less other stuff.
The more starting general proficiencies from int tends to cover that. The thing is, arcane magic is a VERY study-intensive:
“For an arcane spellcaster to have a spell in his repertoire, he must keep track of complex astrological movements and star signs that are constantly changing; he must daily appease various ghosts and spirits that power certain dweomers; he must remember and obey special taboos that each spell dictates. All of these strictures, and they are many, can vary with the season, the lunar cycle, the caster’s location, and more. Having a spell in the repertoire is thus an ongoing effort, like maintaining a friendship or remembering a song. Mages may collect spell formula from many sources, but only the most intelligent and learned arcane spellcasters can maintain a repertoire of more than a few spells at a time.”
-ACKS core page 66
So most of that spare brain power that mages have is going to maintaining their spell repertoire. Of course, a mage could conceivably decide to focus less on their arcane study and more on other skills, in which case they would be a custom class which trades a little spell-casting power for other things (say arcane 3 and thief 1, with most or all thief powers traded for proficiency-like special powers scattered accoss the levels, maybe loremastery, or the like too).
You could argue for giving a free collegiate wizardry or other such magic-knowledge proficiency, but really with the mage’s int bonus, it can afford to start with a bookish general proficiency or two.