Damage is one of the Attributes in Divinity Original Sin 2. These statistics are determined by your character’s base statistics. They can be affected by skills, stances, statuses, gear, abilities, and talents.
The damage a character inflicts when successfully hitting an enemy with an item with their equipped weapon, while unarmed or any skill used.
Spell and weapon damage scale differently. Weapons use the weapon value as a starting point, spells use a level-based value as a starting point (see below). However, misc bonuses (e.g. Flesh Sacrifice, Challenge, Death Wish) are also additive for weapons, but they are a separate multiplier for spells. The bonuses factor in as follows:
Weapon damage: Weapon Base * (1+Element%) * (1+Attribute%+WeaponSkill%+Misc%) * (1+Highground%+Crit%)
Spell damage: Base * (1+Element%) * (1+Attribute%) * (1+Misc%) * (1+Highground%+Crit%)
Damage Reference for Spells
This table shows basic damage (10/0 for attributes/abilities) used most often by spells (Mosquito Swarm, Impalement, etc.).
Its intent is to serve as a reference point.
Mosquito Swarm at level 20 with 40 INT and 10 Warfare deals 100% or 199 * 2.5 * 1.5 = 746 damage.
Grasp of the Starved (20 Lvl, 40 INT, 10 Warfare) deals 250% or 199 * 2.5 * 1.5 * 2.5 = 1865 damage.
Impalement (20 Lvl, 40 INT, 10 Warfare, Death Wish, 50% Health) deals 150% or 199 * 2.5 * 1.5 * 1.5 = 1120 damage.
Notes about damage
These are the correct formulas:
weapon: WeaponDamage * WeaponDamageBoost * (1 + character.DamageBoost + CombatAbilityDamageBonus + ScaledDamageFromPrimaryAttribute + SneakDamageMultiplier) * DualWieldingDamagePenalty% * (1 + Stealth% + Distance% + Skill.DamageMultiplier%) * (CriticalHit% + TALENT_Damage% + HighGround%)
skill: SkillBaseDamage * RandomRange% * AttributeDamageScale * DamageBoost% * (1 + Stealth% + Distance% + Skill.DamageMultiplier%) * (CriticalHit% + TALENT_Damage% + HighGround%)
I'm quite sure it is very wrong. Warfare gives more than weapon skills in terms of damage, but this is not how the formula here works - it just makes it equal. You can check in-game using mirror, to see how your damage looks like when weapon skill is maxed vs warfare is maxed. To prove it contradicts the formula :
For base damage 100, weapon skill 10, warfare 0, artibute 10 (0 bonus) :
100 * (1+0) * (1+0+0.5+0) * (1+0+0) = 100*1.5 = 150
For base damage 100, weapon skill 0, warfare 10, atribute 10 (0 bonus):
100 * (1+0.5) * (1+0+0+0) * (1+0+0) = 150*1 = 150
Overmore, for skills : it is most benificial to invest mostly to warfare, then a bit to weapon - but idk exacktly about proportions, especially when it could be base damage depentant.
I did some testing and calculations with damage, the TL;DR is that the objectively most efficient way to increase your damage is to level your bonuses from your attribute, elemental damage (including warfare for physical), and if applicable critical hit and high ground, equally. Attributes however can be leveled up to 40 while skills can only go to 10, and not every attack will critical or be taken from high ground, so this impractical in practice. However, it does mean that when adding stats to your gear, adding a point to your elemental skill will nearly always be more beneficial than adding an additional point of your main attribute.
As an example, with 40 points in your main attribute and 10 points in your elemental skill, 1 additional point into the elemental skill is worth nearly 2 points in the main attribute. At 60 points in your attribute, 1 elemental skill is worth nearly 3.5 attribute points. It should be noted that weapon skills are calculated essential the same as an additional point of your attribute for the calculation so it is in most cases less efficient unless you want the secondary stat it provides (like the reduction to the dual wielding penalty for instance).
Second, critical hit and high ground start off with a bonus of 50% and 20% respectively. This means that leveling critical damage is most effective only after your elemental skill damage (i.e. pyro, warfare, etc.) hits 50% (10 points in the tree), and leveling Huntsman is most effective after leveling your elemental skill damage hits 20% (4 points in the tree). Keep in mind those bonuses are conditional; if the attack is not from height or doesn't crit, no benefit is gained from those points. it's also worth pointing out many builds need points in these skill to unlock abilities, which naturally should be prioritized.
In summary, maxing out your main attribute and main elemental skill is the most effective method for increasing damage. Weapon skills can often be avoided as points spent in other skills will net larger gains. When adding points in the late game, a point of your elemental class can be worth more than a point in your main attribute.
Adding concrete melee and ranged weapon examples would be nice. Also adding a section on status effect damages and teleportation damage makes this a comprehensive reference.