- Piercing, Forking, and Chaining redirect here. For the support gems that produce these effects, see , and .
Projectiles are entities which are produced by a spell or ranged attack which travel independently of their creator until they collide with an enemy or obstacle. Skills that create projectiles have the Projectile or Bow keyword.
All projectiles have a speed, which can be altered by Projectile Speed modifiers. All projectiles also have a duration (which can be infinite), although in most cases this duration is not mentioned anywhere and cannot be modified, unless explicitly stated such as with the skill .
The speed and duration combined determine the distance the projectile will travel, up to it's maximum range. This is important when considering projectiles that have a limited lifetime.
For example, creates projectiles which deal full damage initially, but deal less and less damage the longer they are alive. Increasing the Projectile Speed of Freezing Pulse will cause the projectiles to arrive at the target sooner, and therefore they will deal more damage than a slower-moving Freezing Pulse that traveled the same distance.
Increasing the Projectile Speed of limited duration projectiles will allow them to travel a further distance before they expire.
However, there are effects that occur based on the projectile's current distance from the creature that launched the projectile. For instance:
- will always arm (change into its second form) at a certain distance from its launching point, regardless of its speed
- The damage modifiers from Point Blank and Chin Sol are based the projectile's current distance from its launching point, not how long the projectile has been alive
Ground and airborne projectiles
Most projectiles fly through the air, however there are some that travel along the ground.
Airborne projectiles an be aimed up and down cliffs and other height transitions, and can impact with the ground or ceiling. This can sometimes make them difficult to aim when dealing with a steep vertical angle, as they might fly over the heads of enemies or harmlessly impact the ground at the enemy's feet. Airborne projectiles will travel over most low obstacles such as small chests and rocks.
Projectiles that travel along the ground cannot be fired up or down height transitions, and will instead collide with the edge. They will never impact with the ground or ceiling, but they are much more likely to be obstructed by small obstacles around the environment. Skills that create earthbound projectiles include , , and .
When a projectile collides with an enemy or obstacle, it explodes and is destroyed. This happens even if the projectile is the result of an attack that is evaded or dodged. Intuitively a projectile that is evaded or dodged would continue along its trajectory, but that is not the case in Path of Exile.
There is a family of effects that allow a projectile that hits an enemy to pass through the target without exploding. They are Piercing, Forking, and Chaining. In all three cases, the enemy that is hit takes damage and any other effects from the hit normally, but the projectile does not explode and continues on.
- When a projectile pierces, it passes through the enemy and continues along its previous trajectory.
- A single projectile can pierce multiple enemies, providing it succeeds its piercing checks. A projectile with chance to pierce of 100% or more will always pierce.
- If a projectile forks, it splits into two identical projectiles which each travel at a 60 degree angle from the projectile's original path.
- A projectile can only fork once. Projectiles that are the result of a fork cannot themselves fork.
- When a projectile chains, it looks for target within a certain radius, and travels in the direction of that target. If there are no targets in range of the original enemy, it will not chain.
- A projectile that chains can hit the same enemy more than once, but it must first chain to a secondary target before it can chain back to the initial target. In this way a chaining projectile can bounce between two or more targets multiple times, but a single lone enemy will only be hit once.
Piercing, Forking, and Chaining are mutually exclusive, only one of them can occur for each hit. These effects are prioritized in the above order. For example, if a projectile has the ability to both pierce, fork, and chain:
- Chance to Pierce will be checked first
- if the projectile did not pierce, then it can fork
- if it did not fork, then it can chain.
As a result, projectiles that have 100% Chance to Pierce (such as ) will never fork or chain.
On-hit effects and explosion effects
Some projectiles have an effect that occurs when they strike an enemy or obstacle, while others have an effect that only happens when they explode. Effects that occur on hit will happen each time a projectile pierces, forks, or chains, while explosion effects will not.
- Skills that activate their effect on every hit:
- All other on-hit effects, such as , , etc.
- Skills that only activate their effect when they explode:
Imagine a 50% Chance to Pierce, Projectiles Fork, and Chain +2 Times, and has been launched towards a pack of enemies:that has
- It hits the first enemy and succeeds its piercing check. The enemy is damaged and the projectile continues on its course.
- It hits a second enemy and this times fails to pierce. It forks, and there are now two projectiles which fly in different directions.
- The first projectile
- The first projectile hits an enemy, and succeeds its piercing check, and continues on.
- There are no more enemies in its flight path, and it flies into a wall and explodes.
- The second projectile
- The second projectile hits an enemy but fails its piercing check. Since it is the descendant of a projectile that forked, it cannot fork. The projectile and none of its ancestors have chained yet, so it can still chain two times. It chains and flies backwards towards the previous enemy.
- It hits the enemy, succeeds its piercing check, and continues on.
- It hits another enemy and fails to pierce, but can still chain one more time. It chains towards a nearby enemy.
- It hits the enemy and again fails to pierce. It cannot fork, and has run out of chains, so it finally explodes, dealing Fireball's area of effect damage.
Projectile Damage Passives
Basic Projectile Damage Passives include:
- 3 x Projectile damage (5%)
- 5 x Projectile damage (6%)
- 5 x Projectile damage (8%)
Notable Projectile Damage Passives include:
- 1 x Fury Bolt (12% Increased Projectile Damage, 20 Strength)
- 1 x Perfect Aim (15% Increased Projectile Damage, 20 Dexterity)
For a total of 15 Projectile Damage Passives granting 112% Increased Projectile Damage, 20 Strength and 20 Dexterity.