I recently came across a pretty unique damage (HP) calculation formula in a just as unique and unorthodox RPG, Unlimited SaGa

Strength Damage = 100 x Strength 2 / (Strength 2 + 800) + 4

Skill Damage = 100 x Skill 2 / (Skill 2 + 800) + 4

Rand1 = [0 - (12 x (Max HP - Remaining HP) / Max HP))] uniform probability range
Rand2 = [0 - (12 + 12 x (Max HP - Remaining HP) / Max HP))] uniform probability range

Raw Damage (Bare Handed) = HP Attack Power x (3 + EN Cost) + (Strength Damage x Number of Hits) + (Strength Damage x Growth Rate) x (128 + Skill Damage + Weight) / 256 + Rand1

Raw Damage (Sword, Axe, Staff, Spear) = HP Attack Power x (3 + EN Cost) + (Weapon Power x Number of Hits) + (Strength Damage x Growth Rate) x (128 + Weapon Power) / 256 + Rand2

Raw Damage (Dagger, Bow, Gun) = HP Attack Power x (3 + EN Cost) + (Weapon Power x Number of Hits) + (Skill Damage x Growth Rate) x (128 + Weapon Power) / 256 + Rand2

Final Damage = (Raw Damage x (100 - Defense Power) / 100 - Defense Power) x Combo Percentage

It should be noted that HP acts as a value determining the probability of incuring LP (=Life Points) damage. This is calculated as follows

LP Damage Probability = ((LP attack power x 8 + 20) x (Target Max HP - Target Remaining HP + 1) / Target Max HP x Combo Percentage - LP Defense Power x 5) / 70

Does anyone here know what the point of such extremely detailed damage calculation formulas would be? Having two random variables alone is sort of insane.