So my main problem with determining Vitals and shit like that was how to prevent v2's min-maxing, as well as make damage uniform for each type of Stat based damage unlike in v3.
When I decided to use DnD as a base, It was because the system worked ((so long as you played Vanilla D&D and not homebrew
)) well enough that players at level 1 had equal chances of beating an enemy up to 3 levels higher. (When I finally do post combat rules, you'll see why.) So, Sen at level 1 has 10 HP, An Armor class (more on that when combat rules are posted) of 5, and a STR and/or WIS modifer of 2 for a total of 3d6 Melee or Magical damage.
Let's say Sen is facing an ratkin with 12 HP, an Armor Class of 7 and a total of 2d6 melee damage. Now the stats seem arbitrarily low, but thats the point. To determine if your attack hits, you roll your AGI vs a Enemy Level TN, typically 5 for level 1. On rolling over the target number, you deal your chosen form of damage to the enemy, in this case Sen deals 3d6 Melee to the ratkin. A quick roll says 8 damage. Now the Rat's AC kicks in. I roll 7d6 for the damage resistance, and on 4,5, or 6, 1 point of damage is negated. A quick roll says 2 hits, so Sen deals 6 damage to the rat. On the rats turn, it rolls it's Agi versus Sen's Level TN, once more 5, and rolls a 5. Ratkin deals 2d6 damage to sen, or 9 for it's roll. sen's AC negates 4 of the damage, taking 5 total. (Note during this I didn't roll for dodge. If I was, I would have added Sen's AgI modifer to the TN, and the rat would have missed.
((Note: I will be making maps for when Combat does happen, as that livens up the combat and makes it visually pleasing. Just don't expect anything fancy.))
So, if I had done an arbitrary flat rate, at level 5 sen would have around 90-100 HP, which makes combat go really slow with the Stat system I have. Combat, if any happens is meant to be fast, and as such a HD roll for HP gain seemed to be the fairest. Granted, an obvious flaw with Character creation rolls was shown, so I decided to do the Full Die max as the Starting Health, then each level up added 1dX HP or a flat rate of half the HD.