As you set out to explore Grim Dawn’s war-ridden world, you will inevitably come upon creatures, and even people, that will seek to harm you. On rare occasions, you will have an opportunity to resolve your differences with diplomacy rather than a blade, but options are limited when a frothing rifthound is pouncing upon you.

Grim Dawn’s fast-paced combat will test your mettle as you face off against seemingly unstoppable Chthonic horrors and aether-warped monstrosities. But before you set out to slaughter the hordes of enemies eager to wipe out the last remnants of humanity, it is important to learn about the mechanics that drive combat.

Basic Mechanics

Armor in Grim Dawn is location-based. Whenever an enemy attacks you with a physical attack or skill, an area on your body will be randomly selected to take the hit. The probability goes as follows:

  • Head: 15%
  • Shoulders: 15%
  • Torso: 26%
  • Arms: 12%
  • Legs: 20%
  • Feet: 12%

What this means is that upgrading your equipment is equally important across all armor slots. Wearing low level leg armor can be tempting if it provides you with beneficial stats, but it can also spell your doom if a particularly strong attack lands on your legs.

Landing Hits and Critical Hits

The ability to hit and critically hit is directly tied to your Offensive Ability (OA) and your target’s Defensive Ability (DA). When your OA is higher than your opponent’s DA, your chance to hit and even critically hit will increase.

As you continue to gain more bonuses to your OA, you will reach higher critical multipliers. The highest possible critical multiplier is x2.5, but to achieve this threshold you must either significantly out-level your target or have invested heavily in your OA.

Both weapon attacks and abilities rely on OA to hit and critically hit, so OA is an important attribute for any character. Offensive Ability and Defensive Ability can be increased through Cunning and Physique, respectively, and directly through equipment and skills.

% Weapon Damage

As you discover new abilities, you will eventually stumble upon skills that deal % Weapon Damage. What this means is that the skill takes the damage and effects you would deal on a regular attack and multiplies it by the displayed %. This includes things such as life steal, bonus magical damage and chance on attack item skills.

Example: 125% Weapon Damage on a skill will take your basic attack and multiply it by x1.25

Flat vs. Percent Damage

Damage on equipment comes in two forms: Flat Damage and Percent Damage. Flat Damage applies only to your weapon attacks and does not increase the damage from your skills unless they include a % Weapon Damage component. If found on a weapon, the Flat Damage bonus applies only to that weapon.

Percent Damage bonuses affect all damage dealt of that type, which includes skills and weapon attacks. So if you have a 20% bonus to Fire Damage, all of your fire-based skills will do increased damage, as well as any fire damage you deal on weapon attacks.

Elemental Damage

Elemental Damage is a combination of the three basic magical elements: Fire, Ice and Lightning. When it appears as flat damage, Elemental Damage will be dealt as 1/3 Fire + 1/3 Ice + 1/3 Lightning, divided equally.

Percent Elemental Damage on the other hand is a bonus to all three elements equal to the full value. It is not split evenly. This makes percent Elemental Damage a powerful way to increase several damage types at once.

% Current Life Damage

Percent Current Life Damage is dealt as a fraction of the monster's current health. This causes Percent Current Life damage to be less effective the closer to death the target is. The damage is not a temporary reduction to the target's maximum health.

Note that Hero and Boss Monsters have a high resistance to this damage type.

Life Steal

Percent of Attack Damage Converted to Health is a form of life steal available in Grim Dawn. It functions differently depending on whether you find it on equipment or on a skill. When on equipment, life steal applies only to your weapon attacks. If you use a skill with % Weapon Damage, that component of the skill benefit from the life steal. In either case, only the direct damage is considered for life steal. Damage over Time, such as Bleed or Poison, does not trigger it.

When found on a skill, Percent of Attack Damage Converted to Health applies to all of that skill's direct damage.

Passively Activated Weapon Skills

Some abilities in Grim Dawn are passively activated on your basic attacks. The Soldier and Nightblade masteries provide several examples of this. Each of these abilities has a chance to activate, which is displayed as a percentage. What that means is that on every basic attack you do, you will have a chance of using the ability instead.

As you invest in these skills, their chance of activation will increase. It is possible to get the total chance of activating passive weapon abilities to go beyond 100%. When this occurs, all of your basic attacks will be replaced by abilities and their chances of activation will be used to determine their relative frequency.


Shields are the definitive defensive option for the off-hand. When you are struck by an attack with a shield equipped, you will have a chance to block some of the damage (shields can block any damage type). When this occurs, you will be unable to block again until the shield’s Block Recovery time has expired. This cooldown can be reduced through various skills and equipment.

Some abilities can use the shield when striking, rather than your weapon. In this case, the % Weapon Damage component of the ability will use the shield’s damage rather than your main-hand.

Crowd Control

There are many ways in Grim Dawn with which you can lock down your target’s ability to react to you. These effects are known as crowd control. The following are the various effects players (and monsters) can use to get advantage in battle:

  • Stun - This effect prevents all actions for its duration.
  • Freeze - This effect prevents all actions for its duration.
  • Petrify - This effect prevents all actions for its duration.
  • Knockdown - This effect sends the target flying and crumbling to the ground. The target will stand back up at the end of its duration. Players are immune to knockdowns.
  • Trap - This effect immobilizes the target for its duration. It is particularly strong against melee monsters.
  • Confusion - This effect causes the target to wander aimlessly for its duration. Players are immune to confusion.
  • Fear - This effect causes the target to flee from the caster for its duration. Players are immune to fear.
  • Sleep - This effect prevents all actions for its duration, but will end early if the target takes damage.
  • Convert - This effect causes the target to fight on your side for its duration. Players are immune to convert.
  • Slow - This effect reduces the attack speed, cast speed, move speed or a combination of all three of the target for its duration.

Buffs, Debuffs and Damage over Time

There are many effects in Grim Dawn which can be applied through several different sources. Whenever this occurs, the strongest effect always takes precedence. For example, if two players in a multiplayer session have the same aura active, the player who invested more skill points into the aura will have theirs take effect while the other player’s will not apply its bonuses. For buffs with a duration that are applied from equipment procs, the effects are independent and will stack.


This works similarly for debuff effects. If you apply a % reduction to a monster’s damage by using a skill and then apply the same effect with a weapon attack, only the strongest debuff will take effect. The effects do not stack. In the case that a strong effect has a shorter duration than a weaker effect, the weaker effect will become active once the stronger effect expires. A special exception to this rule are debuff effects which directly modify specific stats or resistances, such as -% Vitality resistance. If two differently named debuffs (ex. Curse of Frailty and Devouring Swarm) both reduce a target's specific Resistance by -%, the effect will stack as they are two unique debuff effects altering the same attributes.

Damage over time (DoT) effects are different. Unlike debuff effects, DoTs stack from different sources and always do full damage. For example, if you apply Poison with your weapon, and then another Poison effect with a spell, both will deal full damage.


Constitution is a secondary health regeneration system which activates outside of combat. It is represented by a yellow overlay on your health bar. Whenever Constitution activates, your Constitution pool will be drained as your health rapidly refills. If you run out of Constitution, you will no longer rapidly regenerate health outside of combat. To exit combat, you must avoid dealing or taking damage for 2.5 seconds.

Constitution can be restored in various ways:

  • Gaining a level
  • Picking up Vital Essence or Food Rations from a fallen enemy or a Journeyman’s Pack
  • Looting an Untouched Meal
  • Dying
  • Speaking to the Cook in Devil’s Crossing (once per game session)


Potions serve as a means to restore your health or energy in an emergency. When your skills and defenses have failed and you find yourself on the brink of death, it is time to drink a potion.


Tonics of Mending restore 25% + 1200 of your health instantly and another 25% over a few seconds. They are on a 12 second cooldown.


Elixirs of Spirit restore 33% + 500 of your energy instantly. They are on a 30 second cooldown.


Pets are powerful companions you can summon to your aid. These can be anything from a trusty raven familiar to a devious thermite mine. All pets scale separately from you and benefit from special bonuses, found on equipment and skills, which only apply to pets.

Some pets last for only a few seconds, while others can be summoned indefinitely. Some pets can also be issued direct commands, such as to attack a specific target or to move to a specific location. These pets will have their health status displayed in the upper left of the screen. Controllable pets have three stances: Normal, Defensive and Aggressive.

  • Normal Stance is the default used when a pet is summoned. It is a balance between the Defensive and Aggressive states.
  • Defensive Stance forces the pet to stay close to you and causes it to attack anything that attacks you.
  • Aggressive Stance allows the pet to roam and attack anything that comes within its line of sight. It will aggressively seek out targets, even ones that have not attacked you.

Advanced Mechanics
Order of Defense

The enemies of humanity are relentless, but there are many methods available to keep yourself alive. It is important to know how the various levels of defense stack up. In order for an attack to land, it must make it through the following defenses:

  • Fumble, Dodge and Projectile Deflection
  • Chance to hit via Offensive Ability vs. Defensive Ability
  • Shield
  • % Reduced Damage from Monster Types
  • Armor
  • Resistances
  • Reduced Damage from Monster Types
  • % Damage Absorption
  • Damage Absorption

Because flat damage absorption occurs only after damage has gone through all your other defenses, it can be a very powerful tool in your survival and should not be underestimated.

Armor Formula

It suffices to say that the more armor you have, the less physical damage you will take, but there are some rules as to how armor functions which make it a little deeper than that.

Armor in Grim Dawn has both a defense value and an absorption value. By default, your armor absorption is 70% across all your equipment. Whenever you take a physical damage hit, your armor will absorb some of the damage, up to the percentage of your armor absorption, but anything above your armor goes completely through.

Some examples:

  • You are attacked for 100 damage and the attack hits you in the torso, which has 50 armor. In this case, you will take 65 damage. 50 of the damage goes through immediately, while the remaining 50 protected by your armor is modified by your armor absorption (30% of 50), which means another 15 gets through for a total of 65.
  • You are attacked for 100 damage and the attack hits you in the head, which has 124 armor. In this case, you will take 30 damage. Even though your armor is higher than the damage inflicted, 30% of the damage will always go through because of armor absorption.
  • You are attacked for 100 damage and the attack hits you in the head, which has 124 armor, but this time you also have a 20% bonus to armor absorption on your helmet. In this case, you will take 16 damage. Your armor absorption is 70% * 1.2, or 84%, which allowed you to absorb 84 damage from the blow.

Offensive vs Defensive Ability Formula

Offensive Ability (OA) and Defensive Ability (DA) are critical to both your ability to deal out damage and in your own survival. If you let your Offensive Ability fall behind as you level, you will find that more and more of your attacks will miss. Similarly, an insufficient Defensive Ability will result in your enemies not only landing blows more frequently but also sometimes landing devastating critical hits. The relationship between Offensive and Defensive Ability is handled through the following equation:

Probability To Hit (PTH) = ((((Attacker's OA / ((Defender's DA / 3.5) + Attacker's OA)) * 300) * 0.3) + (((((Attacker's OA * 3.25) + 10000) - (Defender's DA * 3.25)) / 100) * 0.7)) - 50

The value resulting from this calculation is your chance to strike the target. You may notice that it is feasible for this chance to go over 100. This is where the critical multiplier thresholds come in.

PTH Threshold 1: 70 (1.0 damage)

If your PTH is lower than 70, any attacks that land will do reduced damage. The damage reduction multiplier is equal to your PTH / 70 (ex. if your PTH is 65, you will do 92.86% of normal damage on a hit, or 65/70). It is highly uncommon to go below a PTH of 70, though it can happen against targets that are significantly higher level than you.

Example: PTH = 65, 1-65 hits for 93.33% damage, 66-100 misses

PTH Threshold 2: 90 (1.10x damage)

When your PTH reaches 90 and beyond, you will begin to see critical hits.

Example: PTH = 97, 1-89 hits, 90-97 critically hits for 1.1x damage, 98-100 misses

PTH Threshold 3: 105 (1.2x damage)

At PTH 100 and above, you cannot miss your target. At PTH 105+, you will begin to see the second tier of critical hits.

Example: PTH = 107, 1-89 hits, 90-104 critically hits for 1.1x damage, 105-107 critically hits for 1.2x damage

PTH Threshold 4: 120 (1.3x damage)

At PTH 120 and above, you will begin to see the third tier of critical hits.

Example: PTH = 124, 1-89 hits, 90-104 critically hits for 1.1x damage, 105-119 critically hits for 1.2x damage, 120-124 critically hits for 1.3x damage

PTH Thresholds 5 and 6: 130 (1.4x damage) and 135 (1.5x damage)

The pattern continues for the final two tiers of critical hits. Beyond the 6th threshold, you will no longer see higher critical hit values, but you will see critical hits more reliably.


Conversion is a special stat found on equipment and skills that changes one damage type to another. The way it behaves is different depending on whether it modifies a skill or is found on a piece of equipment.

The order of events for Conversion is as follows: Base Skill > Skill Modifiers > Conversion on the Skill or Transmuter > Conversion on Equipment and Buffs > Equipment, Auras and Passives

If you have a skill, such as a Transmuter, that converts the damage your attack does, then this calculation is performed before any bonuses from other skills, attributes or equipment are considered. Skill modifiers are still applied first. What this means is that if you take a skill that normally deals Aether damage and use Conversion to make it deal Chaos damage instead, then the skill will benefit from % Chaos Damage bonuses instead of % Aether Damage bonuses.

If you have an amulet with 10% of physical damage converted to fire, that means that 10% of all physical damage you deal (regardless of source) will be dealt as fire instead. This calculation is done before any bonuses you receive to physical damage from Cunning, skills and equipment. What this means is that you can change the damage your weapons and skills do to suit the % damage bonuses on your equipment, opening up exciting opportunities for hybrid builds.