As the game lacks any sort of ingame details it seems there is a decent amount of confusion on how certain attributes and stats work and how they related to your build. Thus i decided to put together this guide in hopes to clear this up.

The Attributes of your character are Strength, Dexterity, Intelligence, Focus, and Vitality

Your class determines your primary attribute with this determine your spell power. Spell power is 1 point per point in your primary attribute. Classes have the following primary attributes
Paladin/Warrior: Strength
Rogue/Ranger: Dexterity
Wizard/Warlock/Sorcerer: Intelligence

Currently no class utilizes Focus or Vitality and these are generally considered secondary/tertiary attributes.


Strength grants a direct 1 armor per point. Strength currenty does nothing else unless its your primary attribute.

Update: in addition to its previous value it now also grants a scaling amount of armor penetration, it seems to be about 0.15% but its not entirely clear if this also has a scaling curve or not.

Each point of dexterity grants 1% weapon crit damage. It also grants Critical chance, though I currently don't know the exact rate. It seems there's a diminishing return as 60 points of dexterity grants about 11% critical chance, but 170 only grants +20%, despite being over double the amount.
After the update dexterity and intelligence were modified to have more of a curve to them giving slightly more favorable numbers below 300. 155 dexterity gives 20% crit chance similar to how 170 used to, but now grants 184% which is more than the 1:1 ratio it used to give.

Each point of intelligence grants 1% spell critical damage. The critical chance for spells is seemingly the same formula as dexterity; more testing would be needed to chart out its growth.
After the update this seems to give a similar amount of spell crit/crit chance with the same stat-curve as before.

Each point of focus raises your maximum MP by 5 points and your mana regeneration by 0.1.

Each point of Vitality raises your maximum HP by 5 points and your health regen by about 0.05 points, meaning you won't see an increase in health regen on odd-numbered points.
Its also important to mention it seems your health regen has a base 1 point; the game will say you have +3 from vitality then claim under the health regen section to have 4 from attributes, suggesting its including base health regen.

A somewhat confusing aspect for some seems to be Weapon Damage, Spell Damage, Weapon Power, and Spell Power.

Best way to simplify this is to say Weapon Damage only works on your Left/Right click (or whatever the equivalent weapon swing is for other control methods); while prettymuch everything else is spell power.

Weapon damage is generally just the damage your equipped weapon does. This is further modified by the weapon type as some weapons do 100% of their weapon damage, while others may go as low as 40%.

Update: Weapons now also gain a % of the required attribute to damage. The amount changes based on the tier of the weapon, thus you may have one taking 10%, while a higher tier takes 12%. Its important to note this seems to be minus some base amount of about 20 points of the attribute.

Each point of Weapon Power grants 0.5% increased damage for your weapon damage.

Weapon power has no attribute that boosts it and rather its only base sources of it come from your levels in Ranger (for the title bonus); and your blacksmith upgrades (which seems to cap at +90, or 45% more damage). Some armor enchantments and trinkets can further boost this value.

It is important to mention but anything generated by a Wand, Book, or Staff is still weapon damage and subject to this value, not spell power.

This is generally the flat value listed on your spell. All active skills not tied to your weapon are spells, this includes the axe throw of a warrior, knife throw of a rogue, or mark of the ranger. Despite seeming like martial abilities they only determine their damage by the rank of the skill you have invested for their base value rather than equipped weapons damage. This is then further boosted by spell power.

Similar to weapon power you gain 0.5% increase spell damage per point of spell power. Unlike weapon power, your spell power scales based on your points invested in your class's primary attribute at 1 spell power per point.
This generally puts intelligence characters in a fairly powerful spot as their intelligence will offer spell power, spell critical damage, and spell critical chance; though obviously this means a higher reliance on spells and mana.

Attributes exist for Armor and Elemental penetration. There are not many sources of this. Class skills can grant this, along with some trinkets. Generally though your weapon can be enchanted with this value.

Update: Penetration values were reworked and it was mentioned enemies were giving a bit more armor to try and make things like armor penetration matter more. This also was moved from a flat value to a % value. As described in the update it seems its now just a reduction % in value rather than a flat number, meaning penetration should never result in a negative resistance/armor on its own (not sure how this is calculated for already negative values). That said even at NG+4 i'm not seeing much value in this stat, so it may matter more at much higher levels.

These exists as miscelaneous modifiers on top of the general weapon/spell % increase. These tend to be either increases to all damage types or to a specific damage type, such as an increase to Physical or Lighting damage.
These are displayed assuming a base value is 100%, thus if you have a 10% increase to fire it will be listed here as 110%.

Its worth noting i've also seen "Attack Damage" Enchantments on armor. This doesn't appear on your stats page at all even when equipped. Best i can tell this is a specific boost to weapon hits via their attacks which is their left and right click damaging moves.
The descriptors get a little inconsistent here as i've seen "Attack" and "Skill" used to describe what a weapon can do; which is not to be confused with "Spells" which are all your class abilities.

I didn't know where to put this so heres where i'll stick random information.

Bleed is a debuff that can stack multiple times, how much it ticks for seems to be uncertain at the moment, so more information will be provided later.

Update: It was updated to scale more, but i'm going to be honest i can't see almost any difference.

Poison apparently is unique in that unlike bleed that can stack, it can only stack one time. This is apparently the intention of the devs for you to spread this around in small quanitites to tick away. Hence why apparently the dirk isn't meant to be good, its just meant to be fast and apply some extra dots for the warlock when its up, or apply little amounts on the brambles of the warden, or fan of knives of the rogue.

Fire can apply a burning DoT to enemies. Its not entirely clear if this can stack

Defenses consist of Armor and the Fire, Ice, Lighting, and Poison resistances. These represent the damage reduction or gain for a specific damage type.
Defenses can be reduced to negative via NG+ modifiers or shadow curse, leading to these values being a damage increase rather than a reduction.

Armor and Resistances seem to behave in a similar pattern, having a diminishing return as you stack more of it to determine how much damage you reduce of that type, with Armor representing physical damage reduction, while each element affecting that type of damage.

When a resistance goes negative the formula seems to become far more flag with each point of negative resistance is +0.25% damage increase for the damage type.

• Attributes: Each point of strength gains 1 armor
  
• Blacksmith Upgrade: +60 baseline armor can be gained here.
  
• Equipment: Obviously the armor you wear will grant some amount of armor, obviously the amount will depend on item level and type (Plate giving more than cloth)

• Attributes: This is listed, but i legitimately can't figure out where this value comes from, i swap from character to character and It seems to cap at +10, but I've seen it as low as +3.
  
• Elemental Resistance Upgrade: The magic shop grants up to +80 here (except poison which comes from the potion shop)
  
• Warlock Bonus: 3 to Fire, Ice, Lighting, and Poison resistance per warlock level to all characters.
  
• Equipment: Each piece of armor can add to the base value, and obviously trinkets can add to this such as the infused stones, rings of resistance, and a few other like the dragon scales.

Leveling warlock is a fairly solid method for raising this as a level 20 warlock is 60 extra resistances, more important as NG+ levels will reduce your resistances; and this can help if you don't wish to dedicate armor enchantments to resistances.

This represents your chance to evade a hit and take 0 damage. This default is 0 and outside of class skills, equipment, or the occasional trinket, this value generally doesn't have much increase.

Rogue has the highest base, along with with one guaranteed evade on a cooldown, while other classes can achieve it as part of a temporary buff.

This represents your ability to parry a weapon hit. This seems to work in the same way as a shield in which it only affects the "front" of you, assumedly a 180 degree arc, maybe slightly more narrow.

Parry seems to have a strange calculation, and even better the way the game displays this is not consistent. Generally you get the largest source of parry first, then each source after gets a reduced, first by half, and then to 0.425% value.

For example a pair of daggers granting 50% parry, and two pieces of gear with deflection granting 15% each. This results in 50%+7.5%+6.375% for a total of 63.875. I will note i've seen the game put the trinket bonus of +15% first and then apply the reductions to each after, though it still came out to the same value, so i assume there's a simpler formula to this, and the game simply is breaking down the value individually.

Champion's medal is a purple tier trinket that allows Parry to work from all directions, making parry a bigger defensive tools, though admittedly at the point it can drop you will see a higher rise in elemental (usually lighting) damage and thus its impact on survivability is not as large.
Update: Champions medal was buffed now to also grant a 200% counter-attack on parry which is neat.

it is worth noting there is a global damage reduction stat in addition to your armor/resistances. Trinkets like the protective charm grant 5% damage reduction (10% if its attuned); warrior has a talent upgrade that grants 10/20/30% damage reduction as well. Armor can also have an enchantment on them to grant 5% each as well.

I wish i could provide some insight on this one, but this seems to be a very vague stat. As i've seen it described is it makes a spell come out faster, potentially reducing that half second delay between pressing the button and the spell happening.
This is so difficult to see that i haven't been able to successfully test it, though it seems like the paladin's charge-up spell from their specialization seems to charge to full power a little faster with this stat.

Spells without cooldowns like knife throw on rogue will see more benefit from this, as your delay is the cast time rather than a cooldown, but otherwise it has minimal effect on other spells.

Spell cooldown seems currently to be additive value, though sources are limited. Drinking the tavern drink for 25% and having Celerity for 15% seems to reduce my spell's cooldown from 10s to 6s. I say seeming as without a display number i'm having to manually count the seconds from when it looks like its starting the countdown.

I would mention I think cast-speed is a factor here in that until a spell cast finished "casting" the cooldown doesn't begin. That means when pressing the button the slight delay between pressing the button and the spell happening is effectively added to the time before the cooldown is done.

This section is a little guesswork as no UI elements seem to display these values or reflect these changes as the run goes on. But i've definitely stacked enough bonuses by the end of a run with the sands of time and the Minstrel's Encore set that i nearly eliminated my spell cooldowns, so it may be possible this stat has no diminishing returns to it.

Each point of shadow curse gives a -4 penalty to Armor and Resistances. In addition to this the higher the stacks the more it reduces your character's vision; not only darkening the screen edges, but causing enemies to begin to disappear beyond certain distance until they become fully invisible. This can become so pronounced your character may not be able to see enemies without standing next to them.

After the recent patch less enemies can apply it, but this isn't 0, so shadow curse remains a thing to look out from for enemies.

Update: Rewriting this entire section because the update finally dropped.

Shadow curse gain is a % value that seems like a % chance to gain a shadow curse, or in some cases gaining extra if the % is high enough. Originally this value was additive meaning it was actually possible to reach negative values on this and have shadow curse be removed when applied. The holy water trinket made this extra easy as it seemed like it would set your value to 0% but then still apply all the -% value after. Now this scales in a multiplicative manner and thus is going to be harder to game.

Bonfires exist that can remove the value, along with smaller braziers. The smaller ones remove 3 or 4 shadow curse (though i've seen it remove as little as 1).
The large ones were always half (minimum -8), Thus best practice is to complete a floor to see if the large bonfires exist before using the smaller to maximize loss. I will mention the dungeon level tends to have only braziers, while eventually the courts will only have bonfires, with the floor inbetween having both sometimes.
The crypts area can also have one but this is a bit rare, but it can be nice if you took alot of shadow curse on too early.

While enemies can grant the curse, a few methods exist that are entirely optional on the player's end. Firstly there's shadow portals that can be interacted with. These will generally have 3 choices to them and usually offer a "shadow trinket", a trinket, and a skill upgrade. The shadow trinket is unique to these, but generally grant some sort of boon the more shadow curse you have, this can be weapon power, spell power, weapon crit, or spell crit. The other two choices aren't special and are generally entirely random.
For each one you choose you will gain more shadow curse with a multiplicative value attached to it if you end up going for all of them. Shadow curse gain does not affect this either.

With the update new shadow curse chests also exist that can grant permanent stat increases or gear.

After the last update NG+ got a little more clear in how it works via their patchnotes.

What we know:

• Experience rewards from targets go up by 33% per NG+ level
  
• Enemies Base Armor and Resistances go up by 33% per NG+ level
  
• Enemies do 5% more base damage per New Game+

NG+ levels also reduce your armor/resistances by an amount per NG+ level. Though the rate this happens seems even more dubious now.
Previously NG+1 imparted a -199 penalty to armor, with NG+2 giving the same penalty, only increasing to -399 at NG+3. This might have been a tooltip issue though.

Now it seems NG+2 increases to -299; but NG+3 is -599 up from -399. So not sure if this is a visual bug or not.
Resistances seem less excessive each NG+ level, likely due to less readily available sources of resistances.

I will need to test more to get a general chart for this, as originally i was convinced it jumped every other NG+ level by 200, it swapped to be every level, but rather than 100, suddenly jumped by 300 points between NG+2 and NG+3, so i'll need to play through more NG+ levels to find out.

Otherwise going up in NG+ level allows you to of course unlock the next with each increasing the max level cap of your character by 5. Going from 20, to 25 at NG+1, 30 at NG+2, and so on.

Here is where i'm just going to stick some opinions that aren't really direct facts as to not clutter the upper section.

Update: i'm going to just nuke this for now, i'll re-fill this out after looking a bit more into it.

For now, weapons seem better, but still seem a bit weak compared to spells.

This game has gotten a decent number of updates that have addressed some issues, though there's definitely room for more polish on some of this.
Generally i'm looking forward to maybe some more class-specific adjustments, and maybe more work on skills.