Comparing D+D Classes
One of my biggest problems with D+D is that the classes are poorly balanced, and don’t scale well at various levels. For example, fighters are the best tanks at all levels but their damage ranges from among the top at level 1, to among the worst at upper levels. Mages are ridiculously underpowered at low levels, having the worst damage, worst tanking and no skills to compensate, but are overpowered at high levels (except perhaps when compared to clerics, which are beasts at all levels).
Update: Adding in fighters and theives multiple attacks at high levels really changes things. This chart assumes target is AC 15, thieves are flanking every round, and targets save against a mage’s attack half the time. Mages only saving grace is their area of effect is typically large. Against single targets, they out DPR only clerics, and then only over some level ranges. Mages clearly need a damage boost at pretty much every level, considering they have no armor and no other skills. I would also grant them a basic magical ranged touch attack that does 1d6 + 1d6 per two levels which can be used every round, so they’re not sitting around doing nothing when their spells run out.
Fighters: 18, Plate, +1 for dex
Cleric: 16, Chain, +1 for dex
Thief: 15, Leather, +3 for dex
Mage: 15, Mage armor, +1 for dex
Assumptions: Thieves have 16 dex, everyone else has 12.
Armor does improve, but really not by much. You get magic items, and can buy better armor, but only monks have an inherent AC progression. I would propose that the “tank” classes gain a “defensive skill” ability which increases their AC periodically, but no faster than +1/2 levels, so that mage to hit bonuses can keep pace. Monks would gain that in addition to their bonuses now, so they remain relatively as hard to hit.