Game mechanics

Path of Exile can be intimidating for new players due to the fact that a certain level of understanding of game mechanics is demanded of players who wish to survive. Thankfully, the developers pride themselves on succinct and consistent tooltips, which make it easier for players to plan ahead or predict the success of certain strategies. In order to help facilitate planning and execution, this page contains information on the most important mechanics to understand and links to pages which explain specific mechanics in greater detail. It is intended to serve both as a guide to new players and as a primary reference for existing ones.

Players that are most worried that they will miss hidden mechanics or important calculations should skip to the Skill Gems section and read from there onwards.

Most of the information on this page is here thanks to Malice's Mechanics Thread. Some information was adapted with permission from Noperative's General Guide to Path of Exile (hereafter Noperative's guide) where listed.

Leagues

Main page: Leagues

There are 2 parent leagues in Path of Exile: Standard (SC) and Hardcore (HC). If you die in hardcore, your character will be moved to standard (your storage is untouched). Everyone you see in Hardcore has never died.

Aside from the parent leagues, Path of Exile releases 4-month child leagues of the parent leagues. These are like ladder resets, in that everybody joins the league with no characters and an empty stash. Child leagues are also slightly different from parent leagues - they will always have brand new modifiers and new items that may drop exclusively in one or both leagues. After four months elapse, each child league is merged with its parent league. Higher level players consider the parent leagues "dumping" or "legacy" leagues for this reason - inflation and power creep can be a turnoff to players.

Here is a simple simple summary of how death will affect your league:
Standard -> Standard
Hardcore -> Standard
4-Month standard -> 4-Month standard
4-Month hardcore -> Standard

As an example, the first pair of child leagues was Anarchy and Onslaught and ran from June 8 2013 to October 8 2013. In Anarchy, rogue exiles could spawn in nearly any non-town area. Onslaught was a hardcore league in which all monsters had the Onslaught modifier, which grants 20% increased cast speed, attack speed, and movement speed. There were some Anarchy-specific unique items and some Onslaught-specific uniques. Newly added diamond and amethyst rings could drop in either league. The items Prismatic RingPrismatic RingRequires Level 30+(8-10)% to all Elemental Resistances, Onyx AmuletOnyx AmuletRequires Level 20+(10-16) to all Attributes, Thief's TormentThief's Torment
Prismatic RingRequires Level 30+(8-10)% to all Elemental Resistances(10-16)% increased Quantity of Items found
Can't use other Rings
+(16-24)% to all Elemental Resistances
+(40-60) Life gained for each Enemy hit by your Attacks
+30 Mana gained for each Enemy hit by your Attacks
50% reduced Effect of Curses on youThe ring I stole,
My finger they took,
A shrouded mind,
Cut their curses short,
As I drained their spirit
And stole their soul.
A blessing is often a curse., Lori's LanternLori's Lantern
Prismatic RingRequires Level 30+(8-10)% to all Elemental Resistances+10% to all Elemental Resistances
(6-8)% increased Movement Speed when on Low Life
31% increased Light Radius
+(20-25)% to Chaos Resistance when on Low Life
Damage from Enemies Hitting you is Unlucky while you are on Low LifeBy its light, Lori led her young charges to safety
and bound up their wounds.
Her sword arm was iron, yet her heart gentle
and proof against hate., AstramentisAstramentis
Onyx AmuletRequires Level 20+(10-16) to all Attributes+(80-100) to all Attributes
-4 Physical Damage taken from Attack HitsMindless rage will shake the world,
Cunning lies will bend it.
Reckless haste will break the world,
And into darkness send it., Carnage HeartCarnage Heart
Onyx AmuletRequires Level 20+(10-16) to all Attributes+(20-40) to all Attributes
+(10-20)% to all Elemental Resistances
(1.2-2)% of Physical Attack Damage Leeched as Life
50% increased total Recovery per second from Life Leech
(30-40)% increased Damage while Leeching
Extra goreForged from the blood of countless wars,
its thirst has only begun., Eye of ChayulaEye of Chayula
Onyx AmuletRequires Level 20+(10-16) to all Attributes20% reduced maximum Life
30% increased Rarity of Items found
Cannot be StunnedNever blinking, always watching.

This item can be transformed with a Blessing of Chayula and Kaom's HeartKaom's Heart
Glorious PlateQuality: +20%
Armour: 931Requires Level 68, 191 StrHas no Sockets
(20-40)% increased Fire Damage
+500 to maximum LifeThe warrior who
fears will fall. could not be obtained. Gifts from AboveGifts from Above
Diamond RingRequires Level 28(20-30)% increased Global Critical Strike ChanceTrigger Level 10 Consecrate when you deal a Critical Strike
(30-35)% increased Global Critical Strike Chance
(10-15)% increased Light Radius
(40-50)% increased Rarity of Items Dropped by Enemies killed with a Critical Strike
50% increased Damage while on Consecrated Ground
+5% Chance to Block Attack Damage while on Consecrated GroundGod blesses those who bless themselves. was only found in Anarchy, and Death RushDeath Rush
Amethyst RingRequires Level 46+(17-23)% to Chaos Resistance+(300-350) to Accuracy Rating
+(260-300) to Armour
+(40-50) to maximum Life
+(15-20)% to Chaos Resistance
(0.6-0.8)% of Physical Attack Damage Leeched as Life
You gain Onslaught for 4 seconds on KillTo truly appreciate life you must be there when it ends was only found in Onslaught. After both leagues ended, diamond and amethyst rings, the new uniques, and rogue exiles were added to all permanent and future four-month leagues.

The previous child leagues were Domination and Nemesis, and Ambush and Invasion. There currently are no child leagues. The next child leagues will run approximately 1 month from now.

This section adapted from Noperative's guide.

Private Stash

Main page: Stash

Your private stash allows you to store items and transfer them between characters. Stashes are shared between all your characters within a league - all of your Standard characters access one stash, while all of your Hardcore characters access a different stash. Items cannot be moved between leagues except by death to a character. Each account is initially limited to 4 stash tabs, but more can be bought through microtransactions.

Character limit

Each account is initially limited to 24 character slots, but more can be bought through microtransactions.

Chat Channels

Main page: Chat Console

There are two types of chat channels: Trade and Global Chat. These channels are League-specific. If you enter global chat in Domination League, then you will only be talking with people from Domination League. There are a large number of channels and you will be automatically allocated to a channel when you first join. Typing /global ## or /trade ## will put you into that number channel, provided it is not full. Messages preceded by # are sent to the global chat channel you are in, messages preceded by $ are sent to the trade channel you are in, and messages preceded by & are sent to your guild chat if you are in a guild. You can leave global or trade chat by unchecking the "Join Global Chat" or "Join Trade Chat" options on the chat window.

This section adapted from Noperative's guide.

Skill Gems

Main page: Skills

Skill gems (also called Virtue Gems) are the manner in which player characters are able to use and augment skills. Dragging a gem into the appropriate socket with place it in that socket, and right clicking will remove the gem. Gems are either skills or supports, and skills currently come in two main varieties: spells, and attack skills. You can tell what category a skill gem is in by reading the gem's keywords - the tags are listed in grey text directly under a skill's name in the mouse-over description of the item.

Skill Types

Any skill that uses your weapon damage counts as an attack skill, and everything else counts as a spell. Read to Damage Scaling and Effects for important information how to build and use Skills more effectively.

Attacks

Main page: Attack

Attack skills are dependent on your weapon, and so are affected by attack speed, accuracy, global and weapon critical strike modifiers and relevant damage mods. Any bonus damage that reads "Adds x-y damage" bonuses (integer damage bonuses) apply to attacks, but not spells. Normal Attack is an attack but is not a skill.

Attacks can be projectile attacks or melee attacks. By default, bow and wand attacks are projectile attacks while all other weapons (dagger, claw, sword/rapier, axe, mace/sceptre, staff) perform melee attacks. Currently Spectral Throw is the only skill gem that allows projectile attacks with melee weapons.

Spells

Main page: Spell

Spells do not draw their damage directly from your weapon. They are affected by cast speed, spell damage, spell gem and global critical strike modifiers, and relevant damage mods. Curses are spells that do not deal damage. A game entity may only have one curse applied at a time unless otherwise affected by a keystone passive, a unique item, or an end-game map modifier. Auras are spells that do not do damage, but instead reserve mana and bestow a specific buff on any affected entities (the player character and the player character's allies).

Some spells are projectiles.

Projectiles

Main page: Projectile

Projectiles exist for a set period of time, so their movement speed determines how far they travel. and can affect distance, but will not extend the time of projectiles.

Traps & Mines

Main page: Traps

Traps are similar to spells, but are not affected by cast speed. They are affected by % trap laying speed, and relevant damage mods. See Traps for more detailed mechanics.

Support Gems

Support gems affect supportable skills in linked sockets. Reading the gem's tags is helpful in determining which support gems can support which skills. Common sense is also helpful - skills that don't do damage, such as Temporal Chains, won't benefit from A frequently asked question is whether added damage gems affect auras. They do not. Note that skill properties may change depending on weapon - Elemental Hit, for example, is tagged with both Bow and Melee because it can be used with either, but won't work when Elemental Hit is used with a sword.

Here is an example adapted from Noperative's guide:

Incinerate can be supported by Lesser Multiple Projectiles, but not Iron Grip.

See Sockets on this page for further mechanical details.

Gem experience gain

• Equipped gems get experience equal to 10% of the experience you earn.
• The number of gems you have equipped has no effect on the rate of XP gain. So having fewer gems equipped does not cause them to gain XP faster than if you had many gems equipped.
• Gems are not affected by the experience penalty when facing enemies below your level.
• Gems do not lose experience when you die.

Classes and stats

Classes

Main page: Character Classes

The main difference between the classes is their stating location on the passive skill tree and their quest rewards. Classes also start with different amounts of attributes:

• Marauder: 32 STR, 14 DEX, 14 INT
• Ranger: 14 STR, 32 DEX, 14 INT
• Witch: 14 STR, 14 DEX, 32 INT
• Duelist: 23 STR, 23 DEX, 14 INT
• Templar: 23 STR, 14 DEX, 23 INT
• Shadow: 14 STR, 23 DEX, 23 INT
• Scion: 20 STR, 20 DEX, 20 INT

Life/mana per level

All classes begin with the same base stats, and gain the same amount per level:

50 life, +8 per level
40 mana, +4 per level
56 evasion, +3 per level

Classes start with different accuracy stats, but gain +2 per level.

Attributes

Main page: Attributes

Attributes are required to equip gear and skill gems. The three attributes also grant some passive bonuses:
Strength grants +0.5 life and +0.2% melee physical damage per point, rounded
Dexterity grants +2 accuracy and +0.2% evasion per point, rounded
Intelligence grants +0.5 mana and +0.2% energy shield per point, rounded

Therefore the +10 attribute passive skills effectively grant:
+10 Strength: +5 life, +2% melee physical damage
+10 Dexterity: +20 accuracy, +2% evasion
+10 Intelligence: +5 mana, +2% energy shield

Life and mana regeneration

All classes have a base mana regeneration rate of 105% of their maximum mana per minute. For example, a character with 100 maximum mana will regenerate 105 mana per minute, or 1.75 mana per second. "Increased Mana regeneration rate" modifiers modify the base rate. For example, 20% Increased Mana regeneration rate would result in 105 * 1.2 = 126% per minute.

Characters do not begin with any life regeneration, but it is available from gear and passive skills.

The rate at which you gain life from life leech is 20% of maximum life per second. If you have 1000 maximum life, and leech 600 life with a single attack, it will take three seconds for that life to be applied to your current life. As long as you do not reach maximum life, you will always get the full amount of life leeched, although it may take time to be applied - if you leech a large amount of life during a battle, you may find that the life gain continues long after the battle is over. Similar to flasks, the life gain from leech will end if you reach maximum life.

The same is true for mana leech, although the rate is 12.5% of maximum mana per second.

Damage Scaling and Effects

See also Damage Types. Understanding how damage scales is very important in Path of Exile. There are currently 5 main types of damage, which are Physical, Fire, Cold, Lightning, and Chaos. Fire, Cold, and Lightning are collectively known as Elemental Damage. Damage reduction from armour only affects physical damage.

Chaos Damage

Chaos damage ignores energy shield, reducing life directly. Chaos damage is not considered to be "elemental damage".

Elemental Damage

Main page: Elemental Damage

Fire damage
If you land a critical strike with an attack or spell that deals fire damage, the enemy is Ignited and begins Burning. Burning causes damage over time. Humanoids, Monkeys and Sea Witches will flee while Ignited. Ignite lasts 4 seconds, and the amount of damage over time is 1/5 of the fire damage dealt per second. So a total of 4/5 of the original damage, over 4 seconds. Multiple instances of ignite can be applied at the same time, however the damage from them does not stack. Only the highest-damage burning effect from a single source that is on a creature at any one time will deal damage. However, burning damage from multiple sources can add on to each other. (See Burning)

Cold damage
Hitting an enemy with cold damage can cause the enemy to be Chilled. Critical hits with cold damage can also cause the target to be Frozen. Chilled enemies move, attack, and cast 30% slower, while frozen creatures cannot perform any action except drink flasks. Frozen creatures can still block, dodge and evade while frozen.

Lightning damage
If you land a critical strike with an attack or spell that deals lightning damage, the enemy becomes Shocked. Shocked monsters or players take 50% additional damage while shocked. The damage multiplier itself applies multiplicatively with your final damage, since it it increasing the damage the enemy takes, rather than the damage you deal.

Status ailments

Ignite, Chill, Frozen, and Shocked are collectively known as Status Ailments. The duration of the chilled, frozen, and shocked statuses is related to the amount of cold/lightning damage dealt:
Shocked: 276ms per 1% max life dealt as lightning
Chilled: 138ms per 1% max life dealt as cold
Frozen: 100ms per 1% max life dealt as cold

All three are capped at considering 1/3 of max life - if you deal more than 1/3 max life as that element, the status ailment occurs as though you did exactly 1/3.

The maximum unmodified durations are therefore:
Shock: 9.2 seconds
Chill: 4.6 seconds
Freeze: 3.33 seconds

If the duration would be less that 300ms, it's ignored entirely (the effect is not applied). For characters using Chaos Inoculation, these durations are calculated based on what the character's maximum life would be if they did not have Chaos Inoculation.

When playing in a party, a monster's max life is treated as being the same as it would be in a single player game for the purposes of calculating these durations.

In a practical sense, this means that the higher an enemy's maximum life is, the more duration needs to be applied. The simplest way to increase duration is to increase damage, which increases base duration.

Dual wielding

Dual wielding grants a +10% attack speed bonus, and a 15% chance to block. The attack speed bonus is applied multiplicatively with other attack speed modifiers. The default attack and most other skills will alternate between each weapon, striking with each hand in turn. Cleave and Dual Strike attack with both weapons at once, while some skills such as Leap Slam only use the main-hand weapon, which is the left weapon slot on the character screen.

Hit & damage calculation order of effects

Main page: Hit Damage Calculation

There are a number of steps involved in deciding whether an attack hits or not and how much damage is done:

1) Avoiding the hit:
- At this stage there is a chance to evade attacks (accuracy vs evasion)
- Any chance to dodge from acrobatics or phase acrobatics is also checked here

2) Avoiding the damage:
- Blocking is checked

3) Mitigating the damage:
- Physical damage reduction and resitances are applied

4) Taking the damage:
- Non-chaos damage is removed from energy shield until it's depleted.
- For Mind over Matter users, 30% of the remaining damage (including all chaos) is removed from mana.
- Any remaining damage (including all chaos) is removed from life.

Stuns

Main page: Stun

Whenever a player or monster takes damage of any type, there is a chance they will be stunned. A stun interrupts whatever that creature was doing while a brief animation is played. The default length of stuns is 350ms. The duration of stuns can be altered by increased block and stun recovery, increased stun duration, and similar modifiers.
For increased block and stun recovery modifiers, the formula used for stun duration is:
350 * (100 / ( 100 + increased recovery) )

The formula used for determining whether or not a stun occurs is:
stun_chance = 200 * damage / defender_effective_max_life

Where defender_effective_max_life is the maximum life of the creature being hit. Increases to monster life from a party of more than one player do not affect defender_effective_max_life. For a player with Chaos Inoculation, their defender_effective_max_life is whatever their max life would be if they did not have Chaos Inoculation.

Reduced stun threshold modifiers reduce the value of defender_effective_max_life. For example, 25% stun threshold reduction means you treat their maximum life as only 75% as much as it actually is, meaning you stun them easier.

There are diminishing returns affecting stun threshold reduction of over 75%. When calculating Stun with Stun Threshold Reduction of over 75%, the Stun Threshold Reduction is treated as being:

75 + ( Stun Threshold Reduction - 75) * 25 / ( Stun Threshold Reduction -50 )

If the stun chance would be less than or equal to 25%, it's ignored, so you need to deal more than 12.5% of effective maximum life to have a chance to stun.

Accuracy

Main page: Accuracy

Accuracy is compared to enemy evasion when determining if an attack hits or misses. Spells will always hit. The complete formula is below:

chance to hit = attacker_accuracy / ( attacker_accuracy + ((defender_evasion/4)^0.8))

Chance to hit can never be lower than 5%, nor higher than 95%, unless you have the passive keystone Resolute Technique.

Critical Strikes

Main page: Critical Strike

Whenever you use a skill or attack, you have a chance to deal a critical hit. Critical strikes are rolled on a per-action basis, not per-monster. If you roll a critical strike when using a skill, you will deal critical damage to all enemies hit by the skill.

Critical strikes do more damage than normal, based on your Critical Strike Damage Multiplier. All characters have a base Critical Strike multiplier of 150%, meaning a critical strike does 150% of normal damage. This multiplier can be increased with various skills and modifiers on items.

For instance, with a multiplier of 250%, if you deal a Critical Strike with attack that normally does 100 damage, you will instead deal 250 damage.

The chance to deal a critical strike is taken from the weapon used to perform an attack or attack skill, and in the case of spells, each spell has it's own critical strike chance, which is listed in the skill gem's description. This value can be increased by increased critical strike chance modifiers from spells and gear. For example, if you are using a weapon with 5% chance to crit, and you have 50% increased critical strike chance, you will have a 7.5% chance to score a critical strike.

Critical chance can not be less than 5% nor more than 95%.

Critical Strike Chance and Critical Strike Damage Multiplier are calculated separately for each spell and weapon attack. All weapons and damage-dealing spells have a base Critical Strike chance listed on them. This only affects your chance to critical for attacks made with that weapon or spell. For instance the base critical strike chance on a wand does not affect your chance to critical with a spell.

However, global modifiers that appear on weapons (or anywhere else) can and will affect your chance to crit with any attack or skill. They will stack additively with other mods of the same type, such as those found in the passive skill tree.

Local Critical Strike Chance modifiers (ones on the weapon itself) affect the base critical strike chance of the weapon - the weapon's modified crit chance will be shown in blue on the weapon's description. This makes Critical Strike Chance modifiers that appear on weapons more valuable than other sources on a point-for-point basis.

Non-spell critical strikes can be evaded. See the evasion section above for details.

Combining damage properties

Path of Exile uses wording that is as literal as possible according to the classifications listed on this page so that consistent damage calculations can take place. For example, take Spectral Throw. It is a projectile attack that uses a melee weapon. This means that, for example, a passive node that grants 10% increased physical damage with Two-Handed Weapons will boost Spectral Throw's physical damage when used with a two-handed melee weapon such as a staff, but a node that grants 15% increased melee physical damage will not boost Spectral Throw's physical damage, because Spectral Throw is a projectile attack, not a melee attack. This approach to properties is true of all mechanics in the game, but is most often a source of confusion for damage stacking.

Damage conversion

Some skills and gear can convert one type of damage to another, resulting in a complex damage calculation. Damage conversion stacks additively, and is scaled down to fit 100% if total conversion exceeds 100%. For example, a level 20 gem in combination with Avatar of Fire adds to 72+50% or 122% of cold damage converted to fire damage, which ultimately translates to 100% of cold damage converted to fire damage. Bonuses from both types are applied to the final product as though they were the same type - for example, if you had
100% cold to fire conversion
100 base cold damage
50% increased cold damage
50% increased fire damage
Then you would have 50%+50% increased fire damage (see the following section), or 100% increased fire damage. This means your final damage is
200 fire damage.

Modifier stacking

Main page: Modifiers#Modifier Stacking

In general, integer modifiers are applied before percentages. Percentage modifiers using the words "% increased" or "% reduced" stack additively with one another, while "% more" and "% less" modifiers stack multiplicatively.

When dealing with weapons, some modifiers that are listed on the weapon itself are applied first, before mods from other pieces of equipment, skills, and so on. This includes anything affecting physical damage, such as increased physical damage, added physical damage, quality etc., and also attack speed, critical strike chance, and accuracy. It does not include elemental damage mods. These can be called local modifiers - any modifier marked as "global," such as %increased Global Critical Strike Modifier, is not applied to the weapon first.

Similarly, when dealing with armour, evasion, and energy shield on armour, any modifiers affecting those stats that are listed on the piece of armour are applied first. This includes quality and any other mods directly affecting armour, evasion, or energy shield amount. It does not include mods affecting the energy shield recharge delay or regeneration rate, only the amount of energy shield.

Imagine I have 100 life, and two passive skills that each increase total life by 15%. The total bonus will be 30%, resulting in 130 life. Now imagine I am wearing boots that give +40 life, and have a passive skill that grants +20 life. The integer bonuses are applied first, giving me 160 life, then the percentage bonuses are applied to that subtotal, for a final total of 208 life.

Quality behaves differently on armour and flasks than on weapons. On armour and flasks, it stacks multiplicatively with other modifiers on that piece of equipment. Quality on weapons stacks additively with other % modifiers on the weapon.

For example, let's look at a Horned Casque with +69 armour, 9% increased armour, and 20% quality.
This Horned Casque has a base armour rating of 428. Then the +69 is added to get 497 armour. Then the 9% bonus raises it to 541, and finally +20% quality results in 650 armour.

Another example calculation
If you had a sword whose unmodified damage is 10-20, with the following modifiers:

50% increased physical damage on the weapon;
20% quality on the weapon;
5-10 added physical damage on the weapon;
passive skills granting 30% increased sword damage;
a skill that does 40% increased damage and 30% less damage;

the calculation would would look like this:

Base damage: 10-20
Stage 1, on-weapon modifiers: (10-20 + 5-10) x (1 + 0.5 + 0.2) = 25.5-51
Stage 2, all other modifiers: (25.5-51) x (1 + 0.3 + 0.4) x 0.7 = 30-61

Defensive mechanics

Movement Speed

The base movement speed bonus of your character is 0%, or normal speed. If your movement speed bonus is at 0%, then it will not be shown on the "Defense" tab of the character screen. However, if it is anything else, such as -2%, it will be shown in the "Defense" tab.

Shields and body armours have hidden intrinsic movement speed penalties. Body armour based on armour or armour and energy shield cause 8% reduced movement speed. All other body armours cause 4% reduced movement speed. All armour-based shields cause 6% reduced movement speed. All other shields cause 3% reduced movement speed. These are the nonmagical components; unique body armours such as FoxshadeFoxshade
Wild LeatherQuality: +20%
Evasion: (433-484)
Movement Speed: -3%Requires Level 25, 73 Dex+(20-30) to Dexterity
Adds 5 to 12 Physical Damage to Attacks
+500 to Evasion Rating while on Full Life
(50-70)% increased Evasion Rating
10% increased Movement SpeedTo catch an animal, think like an animal. can modify movement speed further.

Armour

Main page: Armour

Damage Reduction reduces physical damage taken. Elemental damage and damage-over-time are not affected. The base amount of damage reduction depends on the defender's armour total, and the attacker's attack damage:

reduction = armour / (armour + 12*damage)

The amount of reduction is capped; it cannot be more than 90%.

The fact that damage reduction scales with the amount of damage means it is difficult to know exactly how much damage is being reduced. An easy to remember rule of thumb is that to achieve 50% damage reduction, you will need an armour rating equal to twelve times that of the damage being dealt. For example, to achieve 50% damage reduction against a 100 damage hit, you'll need 1200 armour.

In a practical sense, this means that the higher the damage of a single hit, the more armour penetration it has. This also means that higher armour is much more effective against multiple smaller hits rather than one big hit.

Here are two graphical representations of the armour formula:
Effect of X Armour on Damage
Effect of Armour on X Damage

Evasion

Main page: Evasion

Evasion rating increases chance to evade an attack. Evading an attack prevents all damage and other harmful effects from the attack. Only attacks and attack skills can be evaded. Spells cannot be evaded.

Evasion also gives a chance to avoid critical strikes. If an incoming critical strike succeeds its hit roll, a second hit roll is performed to determine if the critical is evaded or not. This second roll is the same as the regular hit roll above (accuracy vs evasion). If this roll succeeds, a critical strike is scored. If it fails, the attack still hits, but only for regular damage. Critical strikes from spells cannot be evaded.

The way evasion is calculated prevents streaky results. Path of Exile uses an "entropy" system to ensure that hit results are evenly spaced out - for example, if an enemy has 33% chance to hit you, then after you are hit, you are guaranteed to evade the next two attacks from that enemy, and guaranteed to be hit on the next (third) hit. Detailed explanations can be found on the evasion page.

Energy Shield

Main page: Energy Shield

As long as you have greater than 0 Energy Shield, you have a 50% chance to avoid stun.

Energy Shield acts as an additional hit point pool on top of life. If you have any Energy Shield remaining when you take damage, the damage is subtracted from the Energy Shield first. Damage is only applied to life once all Energy Shield is depleted. The exception to this is Chaos Damage, which ignores Energy Shield.

Energy Shield will recharge if you do not take any damage for a certain period of time. The default delay is 6 seconds. This time can be reduced with increased energy shield cooldown recovery modifiers from passive skills. The formula for the recharge delay is:
6 * (100 / (100 + increased recovery) )
so 100% increased recovery will cut the delay in half, not remove it entirely.

Blocking

Main page: Block

Blocking an attack prevents all damage and other harmful effects from the attack. Usually, only attacks and attack skills can be blocked, but there are some passive skills and unique items that allow you to block spells.

Chance to block is capped at 75%.

When an attack is blocked, the game first calculates if the attack would have caused a stun were it not blocked. If it would have caused a stun, the blocking animation is played, stunning you briefly. If it would not have caused a stun, then you get a "free" block with no animation. Faster Block and Stun Recovery and Increased Block Recovery modifiers reduce the length of the blocking animation.

Resistances

Fire, Cold, Lightning, and Chaos damage each has its own resistance value (e.g. "Fire resistance") which is viewable in the character sheet. Resistances reduce damage taken (or increase damage if they are negative), and are capped at a maximum of 75% by default. This maximum can be modified by certain skills. There are penalties to resistances in higher difficulty levels. In Cruel difficulty, there is a -20% penalty to player resistances, and this increases to -60% in Merciless.

Adventuring

Currency

Main page: Currency

Instead of gold or other forms of money, Path of Exile uses what are known as "currency items". Currency items are displayed with light tan text color in their item name. In addition to their use as units of trade, each type of currency item can alternatively be consumed for a specific gameplay effect, such as in crafting or gambling a piece of equipment.

When you buy items from NPC vendors, those items will cost some amount of currency (usually low-tier currency). When you trade with players, be prepared to barter or haggle unless a player has listed a "buyout", a set price for the item. Exchange rates between currency items are generally set by the players, as currency items can only be traded up to the next level of currency at a vendor and not traded down.

Using Jeweller's Orbs or Orbs of Fusing on equipment with quality will consume the quality in order to increase the chances of higher sockets or links.

If an item has reached the max number of sockets, it is impossible to use a Jeweller's Orb on it. If a 5-socketed item has reached 5 links or a 6-socketed item has reached 6 links, it is impossible to use an Orb of Fusing on the item.

Here is some basic information on currency tiers which has been adapted from Noperative's guide. The tiers are player-defined and some players may not agree on them.

Mirror of KalandraMirror of KalandraStack Size: 10Creates a mirrored copy of an itemRight click this item then left click an equipable non-unique item to apply it. Mirrored copies cannot be modified.
Shift click to unstack.
God-Tier: These are the rarest and most expensive items in the game. Having just one means you're richer than some people who have been playing this game since it was released.

Eternal OrbEternal OrbStack Size: 10Creates an imprint of an item for later restorationRight click this item then left click on an item to create an imprint. This imprint can later be used to restore this specific item to that imprinted state.
Shift click to unstack., Exalted OrbExalted OrbStack Size: 10Augments a rare item with a new random modifierRight click this item then left click a rare item to apply it. Rare items can have up to six random modifiers., Divine OrbDivine OrbStack Size: 10Randomises the numeric values of the random modifiers on an itemRight click this item then left click a magic, rare or unique item to apply it.
Shift click to unstack.
High-Tier: These are usually items that are valuable in the end-game and are very rare. They are high-value currency items that most players would prefer to save rather than expend. They can be traded for big-ticket items or used on the highest level end-game maps.

Gemcutter's PrismGemcutter's PrismStack Size: 20Improves the quality of a gemRight click this item then left click a gem to apply it. The maximum quality is 20%.
Shift click to unstack., Regal OrbRegal OrbStack Size: 10Upgrades a magic item to a rare itemRight click this item then left click a magic item to apply it. Current modifiers are retained and a new one is added., Chaos OrbChaos OrbStack Size: 10Reforges a rare item with new random modifiersRight click this item then left click a rare item to apply it.
Shift click to unstack., Orb of RegretOrb of RegretStack Size: 40Grants a passive skill refund pointRight click on this item to use it.
Shift click to unstack., Orb of AlchemyOrb of AlchemyStack Size: 10Upgrades a normal item to a rare itemRight click this item then left click a normal item to apply it.
Shift click to unstack., Orb of FusingOrb of FusingStack Size: 20Reforges the links between sockets on an itemRight click this item then left click a socketed item to apply it. The item's quality increases the chances of obtaining more links.
Shift click to unstack.
Trade-Tier: These are items that have high utility and moderate rarity. They are the first items that you can reasonably trade items for and are best saved for the endgame. Some orbs, for example the Chromatic Orb and Orb of Chance, are on the border between trade-tier and low-tier. Whether they fit into one or the other depends on player opinion, patch results and league.

Scroll of WisdomScroll of WisdomStack Size: 40Identifies an itemRight click this item then left click an unidentified item to apply it.
Shift click to unstack., Portal ScrollPortal ScrollStack Size: 40Creates a portal to townRight click on this item to use it.
Shift click to unstack., Orb of TransmutationOrb of TransmutationStack Size: 40Upgrades a normal item to a magic itemRight click this item then left click a normal item to apply it.
Shift click to unstack., Orb of AugmentationOrb of AugmentationStack Size: 30Augments a magic item with a new random modifierRight click this item then left click a magic item to apply it. Magic items can have up to two random modifiers.
Shift click to unstack., Orb of AlterationOrb of AlterationStack Size: 20Reforges a magic item with new random modifiersRight click this item then left click a magic item to apply it.
Shift click to unstack., Jeweller's OrbJeweller's OrbStack Size: 20Reforges the number of sockets on an itemRight click this item then left click a socketed item to apply it. The item's quality increases the chances of obtaining more sockets.
Shift click to unstack., Orb of ScouringOrb of ScouringStack Size: 30Removes all modifiers from an itemRight click this item then left click on a magic or rare item to apply it.
Shift click to unstack., Blacksmith's WhetstoneBlacksmith's WhetstoneStack Size: 20Improves the quality of a weaponRight click this item then left click a weapon to apply it. Has greater effect on lower-rarity weapons. The maximum quality is 20%.
Shift click to unstack., Armourer's ScrapArmourer's ScrapStack Size: 40Improves the quality of an armourRight click this item then left click an armour to apply it. Has greater effect on lower-rarity armours. The maximum quality is 20%.
Shift click to unstack., Glassblower's BaubleGlassblower's BaubleStack Size: 20Improves the quality of a flaskRight click this item then left click a flask to apply it. Has greater effect on lower-rarity flasks. The maximum quality is 20%.
Shift click to unstack., Orb of ChanceOrb of ChanceStack Size: 20Upgrades a normal item to a random rarityRight click this item then left click a normal item to apply it.
Shift click to unstack., Chromatic OrbChromatic OrbStack Size: 20Reforges the colour of sockets on an itemRight click this item then left click a socketed item to apply it.
Shift click to unstack., Blessed OrbBlessed OrbStack Size: 20Randomises the numeric values of the implicit modifiers of an itemRight click this item then left click another item to apply it.
Shift click to unstack.
Low-Tier: These are rarely used in trading. Most are bought by the hundreds or thousands because of higher abundance than utility. Most people will keep a few stacks of these to use on items they own rather than go through the effort of selling them. Some items, such as the Glassblower's Bauble and Blessed Orb, are much rarer than other orbs but are not used in bulk and so they are not as easily accepted as currency.

There is a general copper-silver-gold-like progression that can be memorized to help buy out or evaluate items from other players. The following orbs can be stored and used as currency in order to circumnavigate the process of bartering.
4 Orbs of Transmutation -> 1 Orb of Augmentation (NPC)
4 Orbs of Augmentation -> 1 Orb of Alteration (NPC)
8 Orbs of Alteration <-> 1 Orb of Fusing or 1 Orb of Alchemy (between players; Alteration -> Fusing is NPC and players widely consider Fusing and Alchemy to be 1:1)
2 Orbs of Fusing or Orbs of Alchemy <-> 1 Chaos Orb (Players)
Items on websites like poe.xyz.is are widely listed with buyouts in terms of chaos orbs, orbs of fusing, and exalted orbs.

Other exchange rates vary over time and differ from player to player. The progression above is not considered a law when trading with players.

Items

Attribute requirements

Most gear has attribute requirements that must be met in order to equip it. These requirements come from the base item type and are unaffected by magical modifiers, quality, or number of sockets. If a gem has attribute requirements a character does not meet and the gem is socketed in an item then that character will be unable to use that item. A complete list of gear and attribute requirements can be found [1].

Level requirements

Most items have a level requirement that must be met in order to equip them. There are two factors that affect level requirements:

• The level of the base item type. This is the level that the item starts appearing (and is separate from the itemlevel that affects which magical modifiers can spawn on it). See the item data link above for a list with all item levels. Some of the very low-level base items do not come with a level requirement.
• The level of the magical modifiers. The level requirement for magical modifiers is equal to 80% of the level of the highest-level magical modifier on the item.
• The highest level requirement of the two listed above is the one that appears on the item.

Drop rates

Main page: Drop Rate

Drop tables are uniform across monsters of the same monster level. In other words, the pool of items that can potentially drop and the chance for a particular item to drop are not determined by the type of monster.

Level difference currency penalty

There is a penalty to the chance of currency items (scrolls, orbs, etc.) dropping in areas with a monster level more than two levels lower than a character's level. For each additional level that a character has compared to the area's monster level+2, the chance of a currency item drop is reduced by 2.5%. So a level 30 in a level 20 area will see 20% less currency item drops on average:
2.5*(30-(20+2))=20
A level 30 character in a level 28 area will see no penalty. Currency item Drops are not increased or decreased in this way when fighting in areas above your level. For the purposes of this penalty, your level is never considered to be higher than 68. Therefore a level 75 character receives no penalty in a level 66 area.

There are two modifiers that affect drop rates in the game, increased item rarity, and increased item quantity. There are three potential sources of these modifiers:
- the player (skills, passives, gear etc.)
- monsters (such as bosses and champions)
- Party bonuses
Modifiers from the player stack additively with each other, and are subject to diminishing returns. Modifiers from the party bonus and monsters stack additively with each other, and are not subject to diminishing returns. The total player bonus stacks multiplicatively with the total party & monster bonus.

Item Rarity

Main page: Rarity

Increased Item Rarity % modifiers (or IIR) increase the chances of an item being magic, rare, or unique. IIR increases with diminishing returns but they are only significant at very high IIR values. IIR has no effect on the number or type of currency items, scrolls, or gems that drop. When in a party, only the modifier from the character who lands the killing blow on an enemy is counted. If one of a character's minions lands the killing blow then the minion's IIR is added to the character's IIR and that sum is used.

Magic, rare, and unique monsters have an IIR modifier for drops.

Item Quantity

Increased Item Quantity (or IIQ) increases the average number of items that drop from monsters and chests. It does not affect the type, quality, or rarity of item dropped, only the chance that something will drop. There is no cap on the usefulness of this modifier, as monsters can drop more than one item at a time. The base chance for an item to drop from a normal monster is 16%. This varies between monster types, and special monsters have higher drop chances.

When in a party, each player in the party after the first gives a +10% item quantity and +40% item rarity modifier on drops.

IIQ & IIR modifiers from support gems currently do not work with kills made by damage over time effects, such as the poison from poison arrow. Modifiers from your gear will affect those kills however.

Quality

Main page: Quality

All weapons, armour, flasks, gems, and maps can randomly receive between +1% and +20% quality. This value can be increased by Blacksmith's Whetstones, Armourer's Scraps, Glassblower's Baubles, Gemcutter's Prisms, and Cartographer's Chisels, but is capped at 20%.

The effect of quality depends on the item:
On weapons, increased physical damage (note that this is useless for caster wands!)
On armour, increased Armour rating, Evasion, and Energy Shield
On life and mana flasks, increased life and mana recovery
On utility flasks, increased duration
On gems, the bonus is specific to each gem. For instance, Frenzy gets increased attack speed, while Leap Slam gets increased stun duration. Check gem pages for specifics.
On maps, increases the item quantity bonus from monsters in the map area by 1%.

Modifiers on items

Main page: Item Affix

Modifiers are split up in to two main groups, prefixes and suffixes. A magic item can have only one prefix and one suffix, never two prefixes or two suffixes. Rare items can have up to six modifiers, it is unknown if there is a limit on how many of these can be prefixes/suffixes. A randomly generated rare item (from a drop or Orb of Alchemy) receives between four and six modifiers randomly, with the following odds:
1/12 chance of 6 mods
4/12 chance of 5 mods
7/12 chance of 4 mods

All modifiers have a level associated with them, and will only appear on items whose item level is greater than or equal to the modifier's level.

Lists of available magical modifiers are available in the item data section.

The Culling Strike modifier (found on some unique items and ) causes monsters to die if you strike them down to 10% or less life.

Sockets

There are four types of sockets:

• Strength (red)
• Dexterity (green)
• Intelligence (blue)
• Neutral (white), appearing on Tabula RasaTabula Rasa
  Simple RobeQuality: +20%
  Movement Speed: -3%Item has no level requirement and Energy Shield (Hidden)
  Item has 6 White Sockets and is fully linked (Hidden)

Sockets appear randomly on most equipment. Higher level items can appear with more sockets than lower level items of the same type. The maximum amount of sockets that can appear on an item also varies by the type of item:

• Two handed weapons and body armour can have up to 6 sockets
• Wands, shields, and one handed weapons can have a maximum of 3 sockets
• Everything else can have a maximum of 4 sockets

One exception to this is the starting weapon that appears on the beach at the start of the game. Its item level is 1 but it always has one socket of each colour.

Items are more likely to receive sockets that match their attribute requirements. So an item requiring only dexterity is more likely to have green sockets than red or blue sockets. You can only put a blue (intelligence) gem in a blue socket, red gem in a red socket, etc. Sockets can be linked. The links are shown as gold bars between the sockets. Support gems affect any skill gems in sockets that they are linked to.

For example:

This sword has 1 strength socket, 1 intelligence socket, and 2 dexterity sockets. Every socket is linked to every other socket. In this sword you could put:

• 4 skill gems. You would get access to 4 active skills.
• 3 skill gems and one support gem. You would get access to 3 active skills, and all three would be improved by the support gem.
• 2 skill gems, 2 support gems. You get 2 active skills, both are improved by both support gems
• 1 skill gem, 3 support gems. You get 1 active skill that is boosted by all 3 support gems.

So let's say you put in:

• Cleave skill gem,
• Raise Zombie skill gem, and
• support gem.

You would get a cleave skill that does extra cold damage, and raise zombie skill with zombies that do extra cold damage. You would not get zombies that have cleave, or raise a zombie every time you use cleave.

If two of the same support gem are linked to the same skill within the same socket group, they do not stack. Only the highest-level gem gives a bonus.

Additionally, two skill gems of the same type can be used in separate socket groups, resulting in more than one usable version of that skill. Skill Gems are only affected by support gems in the same socket group. For example, imagine a piece of armour with 5 sockets. The first two sockets are linked in one group, and the remaining three sockets are linked in a separate group. If you put Cleave and Faster Attacks in the first group, and Cleave, Added Fire Damage, and Added Cold Damage in the second group, you would have two different versions of cleave available - one cleave skill that attacks faster, and another cleave that does bonus fire and cold damage. Small letters appear over the skill icons for each support gem you have attached to that skill. This allows you to differentiate between the different versions if you have more than one of the same skill gem equipped.

Item level

Main page: Item Level

Each item has a level associated with it that is equal to the monster level of the area it dropped in. The monster level is shown on the map overlay (TAB key). Magic monsters (blue name) have +1 to their level, and will yield items with an itemlevel one level higher than other monsters in the same area. Rare (yellow name) and unique (brown name) monsters have +2 to their level, and will yield items with an itemlevel two levels higher than other monsters in the same area. You can check an item's level by picking it up on the cursor and typing /itemlevel in the chat box. This item level determines which modifiers it can receive, and how many sockets it can receive.

Charges

Main page: Charges

Some skills grant Endurance (strength), Frenzy (dexterity), or Power (intelligence) charges. Each charge lasts a short duration before it disappears. The base duration is 10 seconds. Gaining a charge resets the duration of all accumulated charges.

Endurance charges are related to the strength attribute and grant +4% physical damage reduction, and +4% to elemental resistances (fire, cold, and lightning) per charge. The physical damage reduction stacks additively with the damage reduction from armour, so that they are both applied at the same time. For example, if a monster deals 100 damage, and you have 8% DR from two endurance charges, and enough armour to prevent 32 of the 100 damage, the incoming damage would be reduced by 40.

Frenzy charges are related to the dexterity attribute and grant +5% attack speed and +5% cast speed per charge.

Power charges are related to the intelligence attribute and grant +50% critical strike chance per charge.

By default characters can have a maximum number of 3 active charges of each type at one time. This maximum can be increased by certain passive skills and unique items.

Parties

Main page: Party

The maximum party size is 6 players.

Effect on monsters

Monsters gain 50% extra life, 75% extra life, or 100% extra life for each additional party member after the first in Normal, Cruel, and Merciless difficulties respectively. For example, against a party of 3 players in Normal, monsters have double life, but when that party goes to Merciless, monsters have triple life. The original life amount is used for the purposes of determining the length of stuns and status ailments from elemental damage - this means monsters will not be harder to stun/ignite/etc. when fighting in a party.

Effect on loot

Each player in a party after the first gives a +10% item quantity modifier and a +40% item rarity modifier on drops. Increased Item Rarity & Quantity modifiers are only counted from the player who lands the killing blow.

Effect on experience

Only party members that are nearby (roughly two screens) receive experience from a slain monster. If one member is in town or too far from the monster they get no XP. Monsters are still made harder by players elsewhere on the level but outside of XP range.

Effect on flasks and killing blow modifiers

Only the character landing the killing blow on an enemy will gain flask charges. The same is true for all +life and +mana gained "when you deal a killing blow" modifiers.

Instances

All areas in Path of Exile are instanced. When you enter an area, a new instance is created. Once you leave the area, the instance will remain in its current state for 15 minutes - if 15 minutes passes with no players entering the instance, it will be closed. This closes any portals you may have had to the area. Entering the same area again will create a new instance with a new randomly generated map. Areas without side areas attached (any area with two or less exits) has a shorter timer, and will only last 8 minutes while empty.

Instances you create are private, and cannot be entered by other players unless they join your party. However, once a player has entered an instance, that instance remains associated with the player even if they leave the party. So it is possible to share an instance with non-party members in some circumstances. The exception to this is towns, which are always public, and cut-throat leagues, where all instances are public - meaning anyone can enter your instances at any time.

Some areas have waypoints. Once activated (by clicking on the waypoint), waypoints allow you to travel instantly to any other waypoint you have activated.

Ctrl-clicking on a waypoint destination in the waypoint menu, or an area transition such as a doorway, will bring up the instance management screen. This screen lists all available instances of the area you ctrl-clicked on, the players inside the instance, and the time remaining until they are closed. It also allows you to create new instances, and enter existing ones. Using the instance management screen you can have more than one instance of the same area open at a time, and choose which available instance you want to enter. This may be useful if one wants to respawn bosses, but note that instances are arranged so that bosses cannot be farmed without traveling a significant distance.

Level difference experience penalty

Level affects the amount of experience you gain from killing enemies, based on the relative level of the player and monsters. A penalty is applied if you are too far above or below the monster level.

There is a safe level range where no penalty is applied, which is equal to three, plus one for every sixteen complete player levels. Any additional level difference in excess of this safe range is called the Effective Difference.

The formula then applied is: Experience multiplier = ((PlayerLevel +5)^1.5) / ((PlayerLevel+5+(EffectiveDifference^2.5))^1.5)

This experience multiplier can never go below 0.02, or 2% experience gain.

So a level 24 character has a safe band of 3+1=4 levels. So from Monster level 20 to 28, there is an effective level difference of 0. At Monster Levels 19 and 29, the Effective level difference is 1. The Effective Difference matters in either direction. Here are graphs of the experience multiplier by monster level and by effective level.

Difficulty Levels

Main page: Difficulty

There are three difficulty levels: Normal, Cruel, and Merciless. Each character must complete Normal difficulty before you can move to Cruel, and you must complete Cruel before you can move to Merciless. The higher difficulties have death penalties, causing you to lose experience when you die. This is sometimes referred to as an "experience penalty," although that term usually refers to the level difference experience penalty. They are 0% for Normal (no penalty), 5% for Cruel and 10% for Merciless difficulty. This is a percentage of the experience needed to gain the next level, not your total experience. Losing experience in this way cannot cause you to drop down a level. For instance, if you have 9% progress to your next level and die in merciless difficulty, your progress will be reset to 0%. There are also penalties to resistances in higher difficulty levels. In Cruel difficulty, there is a -20% penalty to player resistances, and this increases to -60% in Merciless.