What does each point of a stat contribute?

[Off The Record]

For example, what does 1 point of Physique contribute to melee damage? Is it treated as a flat value like a +0.5 or is it treated as a percentage multiplier?

What about Defense? How does that work? If you have 14 Defense, does that reduce damage by 14%? Or is 14 subtracted from damage taken from an attack?

 

[Theron]

Weapon damage is +1/2 (Physique/Aim) further divided evenly between damage types on the weapon you're using.
You also get (Physique/Aim)/2.5 as bonus Accuracy. (Not shown in Codex.)

Reflexes/2.5 as bonus Evasion. (Not shown in Codex but also not subject to the Evasion cap.)

Willpower gives .2 Lust Defense per point.

When an attack gives a save vs a condition, it's usually
Attacker Stat/2 + (1-20) vs Defender Stat/2 + 10
(50% chance if Attacker & Defender have equal stats)
The X Chance weapon flags are Defender Stat/2 + 15
(25% chance if equal.)
Third Eye Aim makes it Intelligence without dividing by 2.

Class abilities have individual multipliers/formulas, so how much a point gives you is variable.

Resistance reduces damage of a given type (Kinetic/Burning/Tease/Etc.) by a percentage, Defense reduces (Physical/Lust) damage by a flat number.
I believe Defense is calculated last (so it's more effective if you have Resistance to the damage type and less if you have a weakness).