Hmm, from the google cache:
I will explain some of the more advanced game mechanics that I often see new(er) players having troubles with or just being asked about in general to a pretty high extent. Also many veterans of game can for sure learn a thing or two here as well.
There will be plenty of examples in order to give some practical tips.
May the Witch Gods enlighten you! 
Click on the section to read it:
Flat damage added to attacks & weapon damage By “flat number”, we mean an amount of damage that is not written on or next to a skill.
If there is a flat damage number on any piece of gear, from passive skills, toggle skills or from devotion node - it will contribute to your weapon damage only i.e. not on spells/skills that lacks weapon damage (like Trozan Skyshard and Judgment).
Examples:
First node in constellation “Rhowan’s Crown”
This “flat” damage will only apply to your weapon damage and spells/skills that has weapon damage. The +30% elemental damage modifier will apply to all your attacks though.
The skill modifier “Steel resolve” to the Inquisitor skill “Word of renewal”
Same deal here, the flat physical damage is added to your weapon damage and the +50% damages applies to all your attacks.
Note the “ racial ” bonuses, these are damage “multipliers” that will increase all your total damage to Chthonics and Eldritch by 12% (multiply damage by 1.12).
Weapon Damage comes both from your actual weapon AND all these flat sources of damage together. On most high-end builds, the flat sources of damage are a major contribution to the build’s total weapon damage and should therefore not be underestimated when you are looking for damage upgrades.
Note: flat damage numbers listed on your actual weapon are weapon specific.
Here is an example “build” https://www.grimtools.com/calc/qNYdWdBZ
The flat aether damage listed on the shield is not added to our main-hand weapon damage.
Flat damage numbers on caster off-hands are global though and will be added to your main-hand weapon damage.
Here is another more tricky example.
Deadly Aim (inquisitor) is a global buff skill. The flat damage added to Deadly Aim from this weapon is then added to weapon damage only.
Here is another example of the same kind as the previous
It adds vitality damage to Blood of Dreeg (Occultist) and Pneumatic Burst (Nightblade) both which are global buff skills. Again, these flat damages are added to your weapon damage. Attack damage converted to health (adcth) a.k.a. “life steal”
First of all, you can ”steal life” from any damage type apart from damage over time (dot). This is in contrast with many other similar games where you can only steal life from physical damage types.
Basically we have two types of adcth:
i) Global adcth that will only affect weapon damage, i.e. you will only get life back from damage you deal if you deal weapon damage.
Examples of global sources of adcth:
Rings/amulets that has “Vampiric” prefix or similar.
Here is a legendary ring with global adcth
Restless Remains component in gloves.
Some armor items can roll with global adcth too. Here are two examples:
Several devotions provides nodes that grants global adcth, like the third node in Ghoul devotion
This devotion is very popular for its proc “Ghoulish hunger” that grants huge global adcth for a short period of time when you really need it:
ii) Skill specific adcth that will use the entire skill’s damage, regardless if the skill only has “pure” damage or has some weapon damage too.
Examples:
The first modifier “Heart Seeker” on the Nightblade skill “Phantasmal blades” which is a skill that uses both weapon damage and flat “pure” damage.
This 10% adcth will apply to the damage that you deal with the Phantasmal blade skill and will be based on the total damage that the skill deals.
Another example is “Reaping Strike” from Necromancer skill tree. This is a skill that can activate from default weapon attacks (more on that further down).
The adcth applies to all damage that this skill deals.
Yet another example is of course the “Twin Fangs” proc from the “Bat” devotion.
Here the adcth is applied to all damage this skill deals.
Now we can look at “Sigil of consumption” which is an Occultist skill.
Another kind of example: procs from items. Why not this weapon which looks kinda cool
the adcth on the “lifestealer nova” only uses the damage that this proc skill deals.
Item skill modifiers
There are some items that grants or improves adtch on skills, like this shield
which will add 10% more adcth on Sigil of Consumption that we previously discussed.
This caster off-hand will provide adcth for the Arcanist skill “Albrecth Aether Ray”, a skill that lacks both weapon damage and inherit adcth.
adcth in weapon/shield
If your weapon has adtch, this will apply to weapon damage only dealt by that particular weapon.
Components like Haunted Steel and Seal of Blades will give adcth to the weapon/shield that you have it equipped it in - i.e. will not provide global adcth.
This is of extra importance if you are dual wielding weapons, using weapon and shield etc. If you are using shield, your shield damage is not used in attacks like “Cadence” (Soldier) and thus adcth on the shield is useless here.
Some skills do hits with both weapon AND shield, like “Blitz” (Soldier).
The “Aegis of Menhir” skill (Oathkeeper) - the shield throwing skill, ONLY uses the shield as source of damage. In such builds, it might be beneficial to have adtch on the shield but not on the main-hand weapon.
Note, the Haunted Steel component comes with a skill called “Bloodthirster” which will grant global adcth for its duration.
adcth in caster off-hand
If you have adcth in a caster off-hand, say Haunted Steel component or Seal of Blades, this will work as a source of global adcth.
Example:
Let’s assume your build has in total 10% Global adcth, main-hand weapon has seal of blades so it has 5% weapon specific adcth. Furthermore your shield has no adcth at all.
The total main-hand adcth is 15% and for off-hand 10%.
adcth and pseudo-pets
If you bind the Bat constellation proc “twin fangs” on pseudo-pets like Storm Totem, Wind Devil, Guardians of Empyrion, the proc will heal you. Same with devotion procs that deals weapon damage, like “Flame Torrent” from the “Fiend” devotion.
What are pseudo-pets? Things that reads “scales with player damage” and has “health” or “invincible” written on it.
Here are some videos by @mad_lee demonstrating this concept:
https://www.youtube.com/watch?v=-VSRbUstQjM
https://www.youtube.com/watch?v=7DLLnApDOtQ
The “Wendigo’s Mark” proc from the “Wendigo” devotion will not heal you if you bind it to pseudo-pets, since that devotion skill/proc lacks weapon damage.
A side note, devotion procs that provides buffs like “Phoenix Fire” from “Alladrah’s Phoenix” devotion will be cast on the pseudo-pet that activates it. Which is kinda useless since Pseudo-pets are immortal and do not need the damage absorption this buff grants (the other things that the buff grants will be applied though).
if skill has “Weapon damage” on it, then global adcth (and your main hand weapon adcth) will work for it just like “skill-specific” does (it will apply to ALL damage done by skill, not just “Weapon damage” part). However, if skill has less than 100% “Weapon damage”, then “global” adcth will be downscaled accordingly (for example, if you use a skill with 40% “Weapon damage” on it, and you have 10% total adcth (global + main weapon adtch), then it’s essentially the same to having 4% “skill-specific” adcth on that skill. That’s why it’s quite hard to heal yourself with skills, that have small “Weapon Damage” (even if their damage is great due to flat damage bonus on skill itself), cause penalty hits really hard. (this paragraph was written by @BOG)
This medal will give Panetti’s Replicating Missiles (another Arcanist skill that lacks both inherit weapon damage and adcth) a way to steal life back from attacks with that skill since it now deals some weapon damage too
Now according to the previous paragraph, we have to scale our global + main-hand weapon life steal percentage to 16% of its value. Let’s say we have 20% life steal in total for our main-hand weapon (global + weapon specific) we will “only” use 0.16 x 20% = 3.2% life steal. That is not much, but it is something at least.
Another thing that is important for life steal / adcth is that monsters have resistance to life leech. Some are even immune i.e. has 100% or more life leech resistance.
I’ve heard that some PoE players thinks that the “converted” in “attack damage converted to health” implies that damage is “lost” i.e. not applied to the monster. This is wrong, it’s just semantics.
All damage is dealt, then you get life back based on your attack’s damage and adcth and the life leech resistance of the monster.
Finally, we will end with an example of a dual-wielding build.
https://www.grimtools.com/calc/YNn4RwpV
We have 6% global adcth that will apply to both weapons.
Our main-hand weapon (left side on screen) has 15% adcth (weapon mod + seal of blades + global).
Our off-hand weapon (right side on screen) has 10% adcth (weapon mod + global).
Here is the thing, Grim Tools can’t separate adcth on the different weapons, it just adds everything up as if each adcth source was global, i.e. 6% Revenant + 2 x 4% weapon + 5% seal of blades = 19%
This is how it looks in game:
Flat properties / stats & weapon damage
Similar to the flat damages that we discussed previously, flat properties like “energy leech” also only applies to weapon damage attacks unless they are connected to a skill. Their effects will scale with the amount of weapon damage you deal, up to 100%
Example, the second node of the “Viper” constellation
Or the energy leech from Arcane Spark
the offensive ability (OA) is global though.
As a contrast example, the devotion proc “Tip the scales” from the “Scales of Ulcama” devotion is a skill and will leech back that energy to each time it his an enemy.
Note that it also applies adcth based on the skill damage it deals.
Here some more flat properties that only applies to weapon damage.
The % reduced resistances on the last node of “Viper” constellation (more on resistance reductions further down)
In contrast to the devotion proc “Hand of Ultos” on the “Ultos, Shepherd of storms” constellation that at first glance seem to do the same thing
Hand of Ultos is a skill, and will apply this form of resistance reduction regardless if it had weapon damage or not.
The flat resistance reduction mechanic on the component Mark of Dreeg also only applies to weapon damage damage
Default attacks/replacers & attacks that activates from those (WPS)
Some attacks are considered “Default attacks” in Grim Dawn, and some are not.
If a skill is a “default attack replacer” it will say so in text in the skill description.
For instance “Savagery” is such attack skill
The key-wording here is “When used as your default weapon attack, …”
NOTE you can bind this skill where you want, you do not have to have on the LMB or RMB slot in the skillbar, it will work as default attack replacer regardless where you put it.
More examples:
Cadance (Soldier)
Fire Strike (Demolitionist)
Righteous Fervor (Oathkeeper)
Beronaths Fury (Shard of Beronath component)
Runic Bolts (Runebinder’s Spellthrower)
Some attacks can activate/proc out of default weapon attacks (and such replacers) like “Markovian’s Advantage” (Soldier) these skills are called “Weapon pool skills” (WPS for short)
If you somehow end up with more than 100% chance of activating such skills, they will be rescaled down. Say you have total chance of 120% by adding up all your WPS chances. A WPS that reads 20% will now be 20/120 = 16.67% and so on.
This is important to take into consideration when you have one or two WPS that are really powerful and that you have invested a lot of skill points into (like “Execution” - Nightblade skill). You want those strong WPS to activate as often as possible.
It is also important to know that each WPS has its own attack animation time. And by adding more and more WPS you can actually lower your DPS.
Some Default attack replacers has “stacks/charge levels” e.g. Savagery.
For instance, when you have 8 charges active, all damage listed on Savagery will be increased by a factor of 1.15 i.e. a total of 15%. This applies also to WPS that activates from Savagery. This means that WPS together with Savagery can be very potent combined with right WPS.
Cadence is special since it is only considered a default attack replacer on its two first hits. The third hit - the “cadence blow” can not have WPS activated from it.
This is a good more advanced guide on WPS Turbo-charge your auto-attacks with default attack replacers and WPS
Resistance reduction (rr)
Resistance reduction (rr) is one of the most powerful mechanics to invest into if you wanna improve your damage output.
There are three basic types of rr
- X Reduced target’s Resistance
- –Y% Resitance
- Z% Reduced target’s Resistance
They work together in a certain order, you can read more about it here Actual Resist Reduction formula
What I do want to point out here is that you can only apply one rr mechanic of the first type and one of the third type. You may apply how many of the second type as you want though.
This is important when you make your build, that you should not grab as many resistance reductions as possible: Get one source of “X Reduced target’s Resistance” rr, as many “–Y% Resitance” as possible and maybe one source of “Z% Reduced target’s Resistance” if you can.
Let’s look at each kind on their own.
The first kind “X Reduced target’s Resistance” you might perhaps have one source that reads “32 Reduced target’s Elemental Resistance” and one that reads “25 Reduced target’s Resistances”. If both are applied at the same time, the monster will get its elemental resistances (Fire, Cold, Lightning) reduced by 32 units and all the other resistances by 25 units.
The second kind “–Y% Resitance” will also reduce the monster’s resistance by that amount of units. Let’s assume we have one source of “–30% Cold Resitance” and one “–25% Elemental Resitances”. The cold resistance of that monster will be lowered by 55% units and the other three elemental resistances by 25 units.
The third kind “Z% Reduced target’s Resistance” is multiplicative. This means that if the monster’s resistance is 50% to begin with and you apply “20% Reduced target’s Resistance” you will remove 1/5 of 50% which is 10%. So all in all, the monster now has 40% resistances of the type(s) our debuff applies to.
Again, read this if you are interested in the actual order these rr applies
Actual Resist Reduction formula
DA/OA reductions
A good way to increase your chance to hit and crit is by reducing your enemies DA (Defensive Ability). This will make your own OA more effective so to say.
In a similar fashion, you can decrease your chance to become hit and crit by lowering your enemies OA (Offensive Ability).
Now, similar to resistance reduction there are several mechanics for this.
What I want you to learn and use is that all the “-X OA” types will stack with each other to form a total “-X OA”. E.g. “Storm Box” (Inquisitor) and the “Annihilation” skill from the Seal of Annihilation component will stack.
Furthermore, the previous mechanic will stack with “Y Reduced Target’s DA” for instance “Rune of Haggarad” modifier “Biting Cold”.
This “build” https://www.grimtools.com/calc/dVbkJx8Z will reduce monsters DA with 365
However, several of the “Y Reduced Target’s DA” can not stack with each other, only the strongest debuff will apply. Thus you can not lower enemy DA with both “Biting Cold” and “Flashbang” (Demolitionist skill). As an example, this “build” will not work: https://www.grimtools.com/calc/nZodnrBN since the DA reduction mechanics of “Crushing Verdict” (Oathkeeper) and Flashbang will not stack.
Same things applies for the reduced targets OA.
Here is a “build” that will reduce its tagets OA with 477
https://www.grimtools.com/calc/r2BpwkzZ
This “build” will not work https://www.grimtools.com/calc/xZyp4v0V since the OA reduction mechanics of “Decomposition” (Necromancer) and “Blackwater Cocktail” (Demolitionist) doesn’t stack.
Damage reduction / absorption
There are several ways we can reduce the damage that we take. One of the most important mechanic is of course resistances. Here I will explain some basics of the other mechanisms that makes you take less damage.
% Reduced target’s damage
There are two kinds of this, one that is for all damage and one that is damage-type specific.
None of these stacks, only the strongest applies - for any particular damage type.
Example, a Necromancer “build” that has “Ill Omen” - reduces target’s Physical damage, and “Decay” (the first modifier to “Ravenous Earth”) - reduces all damage.
https://www.grimtools.com/calc/RZRQGgKV
Ill Omen will reduce target’s physical damage by 25% and Decay will reduce all the other damage types by 20%.
x% absorption
These mechanics stacks multiplicative with each other.
Example: A Battlemage (Soldier + Arcanist) that uses “Menhir Bulwark” (15%) exclusive skill and “Maiven’s Sphere of protection” (20%) toggle skill.
https://www.grimtools.com/calc/62aE4kX2
This will not yield 35% damage absorption.
Let’s assume your are about to take x damage.
First Maiven removes 20%, you are left with 0.8x. Then Menhir Bulwark will remove 15% of that, so you take 85% of 0.8x = 0.85 * 0.8x = 0.68x damage.
This is 32% less than x, i.e. in total we have 32%, not 35%, damage absorption.
The actual order does not matter since its multiplicative (multiplication is an abelian binary operator).
Less damage taken from "race"
Some skills, devotion nodes and items provides an extra layer of defenses against certain monster types.
Example, “Word of Renewal” grants at rank 12 “10% less damage taken from Chthonics”.
This we can increase additive even further with Black Tallow. If we have two of those, we take 22% less damage from Chthonics.
Judging from this thread 
♂Racial damage reduction vs. global damage reduction? it is not clear if “Less damage taken from --race–” is additive with “% Reduced target’s damage” or is multiplicative.
Flat Absorption
Some skills provides “flat” absorption like “Inquisitor seal” (Inquisutor), “Blast Shield” (Demolitionist), “Ascension” (Oathkeeper).
This mechanic will reduce all damage “ticks” by that flat amount and is thus very useful against many many small hits (like shotgun spells) and damage over time (dot) effects.
Barriers
Some devotions skills and item skills provides flat absorption via a “barrier”.
Example: Tortoise devotion “Turtle shell”, Crab devotion “Arcane Barrier” and on some boots like these Mythical Voidwalker Footpads
This is how the Tortoise devotion proc looks like.
What these barriers do is that they provide an extra layer of “health” so to say and will become depleted when you have taken enough damage. They are applied last in the chain of damage reduction so they can be quite potent for surviving.
What should be important to note is that their cooldown timer (save for Crab’s Arcane barrier) starts when their particular barrier is depleted. Some barriers are damage-type specific, and some are against any kind of damage.
Crab’s Arcane Barrier you can can actually stack, thus its cooldown works as “normal” skills cooldown so to say.
All of the above mechanics will work together with your resistances, armor (for physical attacks) and shield damage blocked (if you have a shield), in a specific order:
Fumble, Dodge and Projectile Deflection
Chance to hit via Offensive Ability vs. Defensive Ability
Damage blocked by shield
% Reduced Damage
% Less damage taken from a specific monster type/race.
Armor (for physical attacks)
Resistances
Flat Reduced Damage from Monster Types
% damage Absorption
Flat damage Absorption
(Here I assumed that Less damage taken from --race-- is multiplicative with “Reduced target’s damage”)
Damage conversions
Damage conversion is extremely important to know about. By using it correctly you can buff your builds damage output significantly. If you are using it incorrect, you can instead gimp your build.
This section will contain many examples by using Grim Tool “builds” with a discussion of why they work as intended 
(or why they don’t).
There are basically three types of damage conversion in Grim Dawn:
i) Skill specific
ii) Global
iii) Armor piercing
We will deal with the first two here and the third - armor piercing, in the next section below.
Damage conversions are applied in the order that is indicated in the list above. This means that some conversions have higher priority than others.
Damage conversions converts the pure/raw flat damage, not +%damage (with one exception, see below). When a flat damage has been converted, we need +%damage of that new type to increase that damage.
Damage conversions affects damage over time versions (dot) of the damage type(s) involved, if applicable (e.g. fire to aether conversion can not convert burn damage into aether dot damage since there is no such damage in the game. Burn damage will stay unconverted in this case).
Any unity of damage can only be converted one time. You can not convert from x to y and then from y to z (or back to x again). The converted x type damage units that are now y type damage units will stay y type damage.
Let’s say you have this “build”: https://www.grimtools.com/calc/xZypY4eV
All vitality damage on Siphon Souls will be converted into physical damage thanks to our belt.
The physical to vitality damage conversion on the exclusive skill is not gonna bring back any of that physical damage to vitality. What has been converted stays converted! (there are some exceptions though).
The above example dealt with the second kind of conversion, global conversion. Before we discuss more of those conversion, we will first have look at skill specific conversions which takes place before global conversions.
Skill specific damage conversions
There are two kinds of skill specific damage conversions: those that come from skill transmuters (like Discord on Cadence, Tainted power on Albrecht Aether Ray, etc)
Picture: Cadence’s transmuter “Discord”: adds flat elemental damage and converts all physical damage dealt by the third “cadence hit” into elemental damage (1/3 fire, 1/3 cold & 1/3 lightning).
The second kind of skill specific damage conversion can be granted by items, so called “item skill modifiers”.
Here are two examples:
When we use skill specific damage conversion, all the skill specific +%damages WILL change accordingly (global +%damage will not chance with conversion). For instance on this “build” https://www.grimtools.com/calc/4ZD6Jnw2 we are converting all physical damage dealt by Forcewave to become fire damage thanks to our gloves. The +%physical damage on rending force will effectively become +%fire damage (and same with dot: internal trauma > Burn). But, the +%physical damage on Oleron’s Rage will not be converted.
“Ok wait malawi, let’s go back to Cadence. What happens if you use the Discord transmuter with those Mythical Voidsteel Gauntlets you showed?”
I am glad that you asked. Since both physical to elemental and physical to chaos damage will occur at the same stage, and both are 100% - we get more than 100% conversion. The math will now be similar as what we did with the WPS previously, we need to rescale each source of conversion to the “new 100%”. In this case, we get 50% physical damage to elemental and 50% physical to chaos.
Global damage conversions
All global damage conversions are… global 
There is no weapon specific conversion. If you main-hand weapon has some conversion on it, that conversion will also apply to your off-hand weapon damage, and vice versa.
Global damage conversions will affect all pseodo-pets (things that scales with player damage/stats).
If you want to convert damage on “real” pets (things that scales with pet stats) you need to have conversions listed under “to all pets” on gear and skills.
There is one global damage conversion that is kinda tricky, and that is “elemental damage converted to x”. This will take place before all individual elemental type conversions like “fire damage converted to x”. Have a look at this “build”, the rings have elemental > aether and belt has “fire to aether” https://www.grimtools.com/calc/RVvJErkV
Let’s say we start with 100 flat fire damage, the rings will convert 2x25% = 50% > 50 of that fire daamge to aether. Now the belt only has 50 flat fire damage left to convert: 50% of 50 is 25. In total, we have 75% Fire damage to aether damage conversion on that “build” and not 100% as we naively might have thought.
One should also note that “x% elemental damage converted to y” account for all three elemental damages at x%, not x%/3. Say you have 30% elemental damage converted to physical damage. This means that 30% of your fire dmg, 30% of your lightning damage and 30% of your cold damage will be converted to physical. Same holds for the DoTs.
Example of both skill specific and global conversions
Shadow strike “build”: https://www.grimtools.com/calc/JVlWyDj2
The swords will convert 50% of all pierce damage on Shadow Strike first, and then the helm will convert 25% of the remaining pierce damage. This is because the skill specific conversion on the swords will occur before the global conversion granted by the helm. In total, we have 62.5% pierce to cold damage conversion on Shadow strike here.
Examples when you can convert damage twice
Guardians of Empyrion (Oathkeeper) has transmuter that converts their damage from physical & fire to acid and vitality. This is implemented in the game as a skill switch, NOT a real conversion. This means that if you use their transmuter and then let’s say this caster off-hand Mythical Word of Inquisitor Abalon - you will now convert some of their vitality damage to elemental damage.
Another example is Storm Totem (Shaman) and it’s transmuter that converts its lightning damage to vitality. In this case, we can NOT convert “twice” - this used to be the case however, but was changed a few patches ago.
Armor piercing
Armor piercing is a conversion from physical damage to piercing damage.
It is a global conversion that happens after all other conversions from physical damage has been done, e.g. Physical to Fire damage conversion.
In order to use this conversion, your skill must have weapon damage component. For instance the Oathkeeper skill Judgment has physical damage but no weapon damage. We can therefore not convert it into piercing damage via armor piercing.
Armor piercing is also weapon specific, i.e. your main-hand weapon can have say 50% armor piercing and your off-hand weapon can have 40% armor piercing.
The value under its base damage indicates the inherit armor piercing ratio.
Because armor piercing is a conversion, it can not convert physical damage that has been acquired as a result from another conversion. Say you have flat fire damage that you convert into physical damage. This physical damage can not be converted again.
In order to increase your weapons inherit armor piercing, you need “increases armor piercing by …%”, for instance if you are using at least one sword a node in the “Blades of Nadaan” will increase your weapons armor piercing value by 100%.
That means, that if the inherit armor piercing value your weapon had was x%, it is now 2x%.
What is good to know about increased armor piercing is that it is always global. In the case above, as long as you wear at least one sword, your other weapon will also benefit from the increased armor piercing that the constellation node provides.
Similar situation if you insert a Blessed Whetstone it will affect the armor piercing of your other weapon(s) regardless in which weapon you put it in.
All sources of “increased armor piercing” is additive. I.e. Blades of Nadaan and Mythical Will of the Blade will net you (on average, it depends on the roll of the amulet) 135% increased armor piercing. This means that you should multiply each weapons base armor piercing value by 2.35 in this case.
It should be noted that if a weapon as no base armor piercing, it can not be increased further by any means.
Knowing about armor piercing is very important if you are doing a physical damage build. Then you want to avoid it at any cost (if your attacks deals weapon damage that is). And if you are doing a pierce build with weapon damage attacks, you wanna get as high total armor piercing as possible.
You can find items with “increases armor piercing” on some belts and amulets. Some sets offer increased armor piercing as partial set bonus too.
It should be noted that for ranged (gun/rifle/crossbow) there is a huge limitation for how much and how easy it is to get high armor piercing. The reason is that there are no ranged counterparts of Blades of Nadaan constellation or the Blessed whetstone component.
Here is a “build” that we can discuss.
Our main hand weapon (left side in char screen) has 100% armor piercing since its base is 50% and we get 100% increased from blades of nadaan node. Off-hand weapon has 50% armor piercing since its base is 25%.
https://www.grimtools.com/calc/O2G7Yvq2
Grim Tool does not show this but Blade Arc uses only main hand weapon.
This means that when we hit with Blade Arc, we will convert all of Laceration’s flat damage to pierce since we are using the main hand weapon.
If we instead had the weapons swapped, like this https://www.grimtools.com/calc/a2EbknPV only 50% of the flat physical damage on Laceration will be pierce, since now our main hand weapon has 50% armor piercing.
Here is another “build” https://www.grimtools.com/calc/qNYdo3AZ
Our main hand weapon (left side in char screen) has 100% armor piercing since its base is 50% and we get 100% increased from blades of nadaan node. Off-hand weapon has 50% armor piercing since its base is 25%.
The flat physical damage on Guardians will not be converted to pierce, since they do not have weapon damage component. BUT when they proc devotions, your main-hand weapon will be used. In this case, we are proccing “Bull Rush” with them. Since that proc has weapon damage, it will use your main-hand weapon “properties”. In this case, our main-hand weapon has 100% armor piercing, and the flat damage on this proc will get converted to pierce damage.
This strategy is utilized in this build https://www.grimtools.com/calc/lNk8OgR2 (see this thread [1.1.5.2] Wrath of the Unknown Assassin - CDR/Proc dw melee pierce infiltrator ~5:30 170 (g3/4) (c+) (sr+) ) where the Inquisitor seals can be more or less spammed since the build has huge CDR. Then he he bound bull rush to them. Since Inq Seals are pseudo-pets, they will use the main hand weapon properties when proccing devotions. In this case, he must use the weapon that has armor piercing. The off-hand weapon has NO armor piercing.
Where can item x drop?
Not technically a game mechanic question, but I see this being asked A LOT so why not covering it here as well?
There are basically five categories of “drops” in Grim Dawn:
- (1) Random Drop only
- (2) Monster Infrequent (MI), items that only drops from special monsters
- (3) Faction items, items that only can be bought from the faction vendors at a specific status.
- (4) Items and Blueprints that can be bought at “Special” vendors. Some of them also sells some MI’s. I refer to this guide by @Strannik for a list over what MI’s can be sold at any given vendor Unique Merchants of Cairn
- (5) Secret/hidden items that are part of quest rewards such as Blazeheart or from destroy-able objects such as Totally Normal Shield
I have some videos on my YouTube channel that shows where some of these hidden items drops https://www.youtube.com/channel/UCCLGxlUZ97AGWiSIjIioUiA
How do I tell what item belong to which category and where do I find this monster?
Clever usage of Grim Tools item database can help you: https://www.grimtools.com/db/ it has many functions and you can also use the world map https://www.grimtools.com/map/
Let’s take an example of item from category (1) Mythical Wrath of Tenebris Grim Tools provides no information about where it can drop so it is a random drop. As opposed to this weapon Soulrend which belong to category (2) - it is labeled “MI” in the upper right corner and below the item description it lists which monsters that can drop it. In this case it is Alkamos, the boss of the Steps of Torment skeleton key dungeon (aka Rogue-like dungeon).
Here is another MI weapon (category (2)) Korvan Eldritch Halberd it has “MI” in the upper right corner. Below its item description we get a list of which monsters that can drop it. In order to see where those monsters are located (can spawn), we go to the “World map” and simply search for those monsters. Let’s start with “Animated Watcher”. You will get many hits. Take the first hit, right click and select “open in new tab”. Now you can click on “Spawn locations” and “Notable loot” to see where those monsters can spawn and what the chance is that they drop such MI when you kill it.
You might have noticed that some items have “Ashes of Malmouth” or “Forgotten Gods” label in the lower right corner in Grim Tools. This means that you need that DLC for the item to be dropped. It does not mean that they only drop in AoM or FG areas. For instance this shield Fleshwarped Defender can be dropped outside Homestead.
When it comes to MI’s that can be bought from certain vendors, I will refer to this guide Unique Merchants of Cairn
For blueprints that can be bought, you can search in Grim Tools database “can be sold by”
or just type in the name of the vendor, e.g. “Hyram”
It should be noted that some items can ONLY be acquired by crating, i.e. you need the blueprint, whereas some items can be dropped and also has a blueprint. I am not aware of any such list though.
Faction items, you can search for “faction” in Grim Tools database, or name of the faction e.g. “Devil’s Crossing”
or you can just investigate each faction’s inventory by selecting that faction in the start menu
Faction items/blueprints can ONLY be bought, they do not drop in game.
All faction items are soulbound (can not be placed in the shared stash) with the exception of Mandates and Experience potion. Learned faction blueprints will be accessible to all your chars though. Same with an item that has been crafted by a faction blueprint, it will not be soulbound.
“Secret” items. Not all have a description in Grim Tools how to get them but some do. For instance Totally Normal Shield reads “Drops from Urn cluster”. If you click on “Map” you will be directed to the world map with a couple of circles that will blink for a short moment (the blinking will stop eventually).
What does count as an “attack”?
“Attack” can sometimes be confusing for beginners, especially if they come from another ARPG.
Of course all ways you deal damage can be counted as iattack, but for this section I will define attacks as something that can trigger “on attack” and “on critical attack” properties.
This is what I mean:
and
and in addition, triggering Inquisitor’s Deadly Aim passive skill
What can NOT trigger such things described above?
- Pets like Summon Familiar, Summon Hellhound, Raise skeleton, …
- Player scaling pets like Guardians of Empyrion.
- Pseudo pets (Wind Devil, Storm Totem, Inquisitor Seal, Rune of Kalastor/Hagarrad, Mortar Trap)
What can trigger such things?
Basically everything else, even debuffs like Curse of Frailty and aura damage like Aura of Censure.
Strangely enough , Occultist skill “Curse of Frailty” can both trigger “on attack” and “on critical attack” even though it dels no damage whatsoever. Same with Soldier skill “War Cry”.
Note that the devotion bindings that are “on attack” is slightly different. I.e. we can assign a devotion proc that is “on attack” on a pseudopet, or pet like Rune of Hagarrad, Guardian of Empyrion or Summon Familiar. But, we can not assign devotion bindings that are “on attack” on damage auras like Aura of Censure.
It should also be noted that the Guardian of Empyrion aura that deals damage can NOT trigger devotions, they must hit with their mace for it to count as an attack for devotion triggering.
When it comes to skills that has multiple projectiles, like Stun Jacks, Ravenous Earth, Phantasmal Blades. Each projectile has a separate “chance to cast” check in terms of activating “on attack”, “on crit” and devotions proccing. If your chance to trigger is x% and you have n number of projectiles you have to calculate the chance of casting it at least once per attack: 1 - (1-x)^n (use x% in decimal representation) and you’ll get the chance in decimal representation.
Example: 20% and 5projectiles: 1 - (1-0.2)^5 = 0.67 = 67% chance.
Similar for skills that affect multiple targets. If you have x% chance to cast on attack, and you affect n targets with said skill/spell you can do a similar calculation.
Note some skills have “ticks” like Ravenous Earth, Curse of Frailty & Word of Pain. The probability we calculated above is for each tick.
Skills & debuffs that do not work on most bosses