Skill (SKL) is one of the main stats of a hero. The total value is shown on the Hero's Profil tab. The base value is increased by Runes, and magnified by Traits, Hero Stars, Hero Rarity and Epics. You can tap and hold the value to see how the stat value is boosted.
The other hero stats are: Attack, Defense, Health, Crit Chance, Dodge, Damage Reduction, Damage Penetration, Chaos Reduction.
How is Skill Used?[]
How a hero's Skill stat is used and how the Skill stat is applied can be confusing as it impacts a large array of Abilities and uses different calculations depending on where and how it is being used.
Breaking down how the Skill stat impacts Abilities into seven distinct categories makes understanding the Skill stat easier to understand.
Healing[]
There are two types of 
Heal Heals in Dungeon Boss, Flat Heals and Percentage Heals. Increasing a hero's skill stat will increase the amount of healing that is done.
Example: Adding 250 Skill Points to 
Bauble will increase his average heal on 
The Furnace from 4800 to 5600 and his Crit Chance from 8800 to 10,200.
Chance to Resist[]
Burning an enemy (
Burned), attempting to inflict Disease on an enemy (
Diseased), freezing a target (
Frozen), are all examples of when a defending hero needs to perform a resist roll to ignore this effect (debuff). Increasing an hero's Skill stat will reduce the chance a target will resist the effect.
- (Base Resist Chance) * (Attacker Skill / Defender Skill) * (SkillResist Coefficient)
Note 1: The SkillResist Coefficent is on a curve. The greater the skill difference the higher the coefficient.
Note 2: If the enemy Hero has greater Skill than the allied hero, the chance to resist is not increased above the baseline roll.
CRIT Chance[]
Skill increases a heroes' chance to cause a 
critical strike. For every 80 points of Skill added, a heroe's CRIT Chance is increased by 1%.
Team Buffs / Active Ability Modifiers (Allies)[]
Any castable ability (Special "Attack") which provides a secondary effect (Buff) to an ally will have that secondary effects quality increased by Skill. To calculate the increase in the abilities effectiveness use this equation:
- (Ability Baseline Value) * (1 + (X added Skill / 20,000))
Example Abilities: 
Kai Makani's 
Call of the Deep, 
Ember Sanguine's 
Fire Mend, 
Cruel King Bramble's 
Goblin Dance Party.
Debuffs by Special Attacks / Active Ability Modifiers (Enemies)[]
Any castable ability (Special Attack) which provides a negative secondary effect (Debuff) to an enemy will have that secondary effects quality increased by Skill.
- (Ability Baseline Value) * ((Allied Hero Skill / Enemy Hero Skill) * Skill Value Coefficient)
Note 1: The Skill Value Coefficent is on a curve. The greater the skill difference the higher the coefficient.
Note 2: If the enemy Hero has greater skill than the allied hero, the ability's baseline value is applied.
Note 3: 
Runes with a bonus stat (4th Stat, Passive) such as 
Electric Skin, 
Poison Skin, 
Burning Skin, ... are included in this category.
Example Abilities:
Phenol Thoxian's Jelly Shot- Squinch's Playing with Fire
- Lily Blossom's Sapping Vines
- Kobal the Pestilent's Pandemic Swarm
Synergy Traits / Passive Ability Modifiers (Allies)[]
Any Hero who has an Trait (Passive Ability) that states "boosts allies' (attribute)" is effected by Skill. These Traits can affect the hero self. To calculate the increase in the Trait's effectiveness use this equation:
- (Trait Baseline Value) * (1 + (X added Skill / 20,000))
Example Traits:
- Overlord Executum's Undead Guard
- Cobressa's Viper Gang
- Shade's Dark Shroud.
Debuffs by Traits / Passive Ability Modifiers (Enemies)[]
Traits (also refered as Passive Abilities or just Passives) that in someway debuff enemies use a different calculation to determine the Skill's effectiveness. The Passive Ability increase (Synergy Traits) listed above does not apply to this calculation.
- (Trait Baseline Value) * ((Allied Hero Skill / Enemy Hero Skill) * Skill Value Coefficient)
Note 1: The Skill Value Coefficent is on a curve. The greater the Skill difference the higher the coefficient.
Note 2: If the enemy Hero has greater Skill than the allied hero, the Trait's baseline value is applied.
Note 3: (Passive) Trait's starting Baseline is substantially lower than its (active) Ability counterparts as they do not gain an increase from leveling.
Example Abilities:
- Ferno's Aerial Superiority
- Kobal the Pestilent's Diseased Heart III
- Shadowblade's Plague Spreader
Strength of Debuffs (Special Attack vs Trait)[]
As noted above "(Passive) Trait's starting Baseline is substantially lower than its (active) Ability counterparts as they do not gain an increase from leveling." In other words, this means
- Debuffs that are applied by Special Attacks (an active ability) are stronger than Debuffs that are applied by a Trait (a passive ability).
An example of this is 
Kobal the Pestilent's Trait 
Diseased Heart III, which causes Diseased to the enemy team, reduces the enemy's attack power by 25% while Kobal's primary signature ability 
Pandemic Swarm causes Diseased as well but reduces the enemy's team attack power by 75%.
- → Signature Abilities will always be substantially more powerful than a passive counterpart (Trait).
All hero Traits which cause Disease will apply a 25% attack power reduction.
- Kobal the Pestilent's Diseased Heart III
- Kobal the Pestilent's Plague Spreader
- Shadowblade's Plague Spreader
- Hopper's Rabid
are additional Traits where this is true.
Skill Increase by Level[]
The Trait of a hero at level 1 grants a passive 25% bonus, like for example 
Lord Zomm's 
Slow. At higher levels, for example level 70, the Trait shows a 28% bonus. The reason many Traits appear to get a boost is because the default Baseline for the Trait is still 25% but as the hero is now level 70, that hero has earned 2000 additional Skill points from leveling from 1 to 70.
- 2000 Skill points equals a 10% boost in that Trait's effectiveness. 25% Baseline * 10% bonus = 27.5%, rounded up equals 28%.
Extra Skill from Runes or Allies' Passives like 
Marrow's 
Monster Scout that boosts the Skill stat can increase the bonus of other Traits.