Table 3: Hit Progression and Hit Points after level 9
Normal Man - +0% (+1hp after L9)
Magic User - +15% (+1hp after L9)
Cleric/Thief - +30% (+1hp after L9)
Fighting Man - +70% (+2hp after L9)
Normal Man - +0% (+1hp after L9)
Magic User - +15% (+1hp after L9)
Cleric/Thief - +30% (+1hp after L9)
Fighting Man - +70% (+2hp after L9)
Bonus Hp after L9
(in addition to the standard amount listed above, will also raise xp for L10+)
Bonus +1hp - +10%
(in addition to the standard amount listed above, will also raise xp for L10+)
Bonus +1hp - +10%
Ignoring the hit points after level nine for a moment, I'll try to explain where I got the costs for the hit progression tables. Normal Men never progress at all and are nearly as skilled as a first level magic user, so I gave them the lowest possible cost of 0%. Magic Users suck at combat, but they're far better than Normal Men who never progress at all, so I put their hit chart cost at 15%. This cost gap will accommodate a couple of new and awful hit charts that I might inflict on cross-eyed brownies, blind mole people, or others whose combat skills fall between a normal man and mage. Then I just doubled the cost for the Cleric/Thief (30%), and doubled it again for the Fighter progression (60%). Later I added another 10% to the fighter's table to account for the additional hp after level nine and general awesomeness.
I justified all this to myself much later. If you care to crunch down all the numbers, round profusely, and basically ignore the first few levels; fighters are sort of almost twice as effective at hitting baddies as clerics and three times as effective as magic users. Costs of 20-30-60 seem appropriate based on those ratios. Once I considered that the basics of combat training are far easier to learn than the advanced maneuvers, the 15-30-70 costs made sense to me.
Back to those hit points now. This was originally two different tables, one for hit progression and another for hit points after level nine. I combined them shortly after Table 1 took it's current form. Mainly this came about because at the time I was requiring Halflings to pay for the "after name level" hit points even though they topped out at eighth level. Then I saw that the higher "after name level" xp requirements of Dwarves and Thieves could be blamed on them gaining a hp in addition to those of their combat peers. It all made sense in a weird moment of clarity, so I tied the "after name level" hit points to combat proficiency. Normal Men get +1hp after L9 because I thought it would be sad to level a character from 9th to 10th and not gain a hit point. I'm generous like that. If you decide that Normal Men combatants don't deserve it and should get +0hp after 9th, I wouldn't think less of you.
Now somebody out there is going to ask about the cost of that Bonus +1hp (because I know I did). "Why are thieves and dwarves paying +10% every level in addition to the higher xp after name level?" I'm not sure honestly. This discrepancy convinced me make a new house rule for my own games. Thieves get a minimum of 2hp per level. Dwarves get a minimum of 3hp per level. So, if one of those guys goes up a level and rolls a 1 or 2 for hp, then they get the minimum instead. I mean they're paying for those hp every level, right? It makes sense to me.
Another alternative is reducing the cost of the bonus +1 hp after L9 to 0% (but it still raises xp for level 10+), then raise thief and dwarf special ability costs to compensate. Climb Walls starts off pretty high, so maybe it should cost 15%. Backstab might also deserve to cost 15%. For the Dwarves I'd raise their language skills up to 10% (to match the elves), and their Infravision up to 15%. Then elf Infravision goes up to 15% to match the dwarves, so I'd lower the elves Connection to Nature down to 15%. Hmmm... That looks good actually. Really good. Crap. I wish I'd have thought of this sooner. I'm going back to edit the original post again with these new changes. I'm scrapping the minimum hp house rule that I mentioned a moment ago, I think these changes work out better all around.