Gaols and Giants - The Playground rewrites third Edition

[Eldan]

Amechra brings up a good point we should clear first: the basic mathematics of the game.

I suggest that the basic probability of achieving a level-appropriate standard task should be 55%. That's 10+ on a d20. From there, I'd like an about 10% change per level up or down, that seems good to me.

Now, let's look at how fast modifiers grow. I'll start with the modifier table I said I'd make.
I suggest the following modifiers: Arcane, Armour, competence, dodge, divine, luck, morale, Shield, Size
Notes: Alchemical is gone. Arcane is what used to be called Enhancement, and also includes Resistance, which, as far as I can tell, was just enhancement for saves. Competence includes Insight. Divine is what used to be called Sacred or profane (differentiated now by wording like "This ability gives good creatures a +2 divine bonus to AC against attacks made by evil creatures"). Shield includes the former deflection and applies to touch AC. Dodge is very specialized, I'm thinking about folding that into competence as well.
That's a nice 9 types.
I find the following things these can apply to: Abilities, AC, Initiative, Saves, Attack, Damage, Skill checks. Tell me if I forgot any.

So, what applies to what?

{table=head]Name|Ability|AC|Initiative|Save|Attack|Damage|Skills|Description
Arcane|Yes|Yes|?|Yes|Yes|Yes|?|Spells and magic items
Armour|No|Yes|No|No|No|No|No|Mundane armour
Competence|Yes|Yes|Yes|Yes|Yes|Yes|Yes|Class features
Dodge|No|Yes|No|Reflex|No|No|No|Evading
Divine|Yes|Yes|Yes|Yes|Yes|Yes|Yes|Divine power
Luck|No|Yes|No|Yes|Yes|Yes|Yes|Just that lucky
Morale|Yes|No|No|Will|Yes|Yes|?|Just that motivated
Shield|No|Yes|No|No|No|No|No|Deflecting attacks
Size|No|Yes|No|No|?|No|No|It makes a difference
Total:|4|8|2-3|4-5|5-6|5|3-5
[/table]

And here we run into problems. Namely, that we have many more modifiers on some kinds of checks than others. Which makes scaling difficult. Furthermore, modifiers on abilities have wide-ranging effects on many others. How do we solve this?