In Final Fantasy Zero, when you choose to attack your enemy, you will remove some of their endurance and health — their hit points — representing their growing exhaustion. You do not need to roll to "hit" your target in FFZ: you automatically hit, and deal damage, though certain effects (such as statuses) require some Luck to work.
Physical or Magickal?
Every attack in FFZ falls into one of two categories — it is either a physical attack, coming from your character's real bodily effort of swinging around a violent thing; or it is a magickal attack, manifesting hostility from the aether around you.
You can tell which is which because of two keywords: Techniques, which indicates a physical attack, or Spells, which indicates a magickal attack. Items are a special case that have their own attack and damage values that do not change (and so don't rely on your statistics at all), but even items will either be Phsyical or Magickal.
Melee or Ranged?
FFZ attacks also fall into either the Melee or the Ranged category. Melee attacks are up-close, at arm's length, while ranged attacks are from a distance.
Melee attacks deal one-half damage to creatures in the back row, but full damage to creatures in the front row. They also halve damage if used from the back row. Ranged attacks are the inverse: full damage to creatures in the back row, and half damage to creatures in the front row. They halve damage if used from the front row.
For your basic attack, the weapon you use determine whether your attacks are melee or ranged attacks. Techniques are melee attack by default, while Spells are ranged attacks by default. Tools ignore range entirely.
Weapon Power
Weapon Power is what you roll for damage for Techniques. Weapon power is mostly derived from your Job. The damage you deal is reduced by the target's Stamina.
Spell Power
Magick power is what you roll for damage for Spells. Spell power is mostly derived from your Job. The damage you deal is reduced by the target's Willpower.
