Damage (XC1)

Damage is the means of reducing an opponent's HP to zero in Xenoblade Chronicles. s and s deal varying amounts of damage, combined with the user's stats and equipped weapon.

Damage formula
The damage formula is slightly different depending on whether a party member is attacking an enemy, or the other way around.

For a party memeber as the attacker: (s + w) * a * (1 - d) * r * c * b For an enemy as the attacker: (s - d) * a * r * c * b In these formulas: Finally, the damage value is rounded down if it is not an integer.
 * s is the relevant stat of the attacker: for physical attacks and  for ether attacks. Stat-manipulating effects are applied here.
 * w is the weapon's attack. It is a random number between the weapon's minimum damage and the weapon's maximum damage. Weapon-manipulating effects are applied here.
 * In the original Wii and 3DS releases, a bug causes the maximum damage to never be above the minimum damage plus 99. This is fixed in the Definitive Edition.
 * a is the arts multiplier. Most auto-attacks have a multiplier of 1.0.
 * d is the defence of the target. Whether it is physical defence or ether defence depends on the attack being used. Effects that manipulate defence are applied here, but not those that manipulate damage taken.
 * For party members, it is the sum or their personal defence and the defence of all equipment they are wearing.
 * For enemies, it is the multiplier of their relevant defence stat, if the attacker is placed in the correct direction.
 * r is the sum of most remaining effects, such as modifying damage taken, or a skill that does more damage to certain species.
 * c is 1.25 if the attack is a, otherwise it's 1.0.
 * b is 0.5 if the attack is blocked, otherwise it's 1.0.

If the target is immune to the attack, the result of the damage formula is skipped entirely - the target takes only 1 damage, or 0 if the attack is blocked. This is altered in the Definitive Edition, where the damage done is reduced to 1 as part of the formula. This results in a few changes:
 * Damage bonuses such as those of still apply, so Shulk will deal 2 damage instead of 1 from behind.
 * The damage dealt by debuffs such as bleed is, instead of always being 1 per tick, equal to the debuff's normal damage of "a percentage of the triggering damage". As damage always rounds down, this means each tick does 0 damage unless the debuff's value is 100%.