On this page
- Direct answers
- Definitions
- What happens on a single collision
- Behaviour pairing matrix
- Chain from enemy vs chain from terrain
- Worked examples
- Clear speed vs bossing
- Skills and items that forbid behaviours
- Common mistakes
- Common points of confusion
- Video guide
- Frequently asked questions
- Sources and verification
- Changelog
QUICK ANSWER
Direct answers
What is the collision priority order for projectile behaviours?
Whenever a projectile collides, it checks its remaining behaviours in this priority: Split, then Pierce, then Fork, then Chain, then Return. Only one behaviour can occur on a single collision, so the first one it still has available wins.
Can a projectile Pierce and Fork or Chain on the same hit?
No. Only one behaviour applies per collision. A projectile that Pierces does not Fork or Chain from that enemy; Fork/Chain from enemies only become possible after Piercing and Forking are exhausted.
Do all projectile skills support all four behaviours?
No. Some skills or items explicitly forbid a behaviour. For example, Lightning Arrow cannot Chain (including from terrain), and Freezing Pulse Pierces all targets so it cannot Fork. Always read the skill tooltip.
Does Return let a projectile hit the same enemy again?
Unlike the other behaviours, Return allows one extra collision per simultaneous set against targets that were already hit. A projectile normally Returns only once.
OVERVIEW
Definitions
Projectile behaviours are special properties a projectile can carry. They decide what happens when the projectile hits an enemy or an obstacle instead of simply stopping. Four of them are the focus of this guide: Pierce, Fork, Chain, and Return. A fifth, Split, shares the same priority system and is described for completeness.
These behaviours are usually added by support gems (Pierce Support, Fork Support, Chain Support, Returning Projectiles Support) but can also come from a skill's own text, unique items, or passives. They are not all compatible on a single hit — only one resolves per collision.
- Projectile: an entity that travels independently until it collides with an enemy, an obstacle, or reaches its travel limit (about 15 metres).
- Pierce: the projectile passes through the enemy it hits and continues on its original trajectory. This still counts as a hit.
- Fork: the projectile splits into two identical projectiles that travel away from each other at 60 and -60 degrees from the original path.
- Chain: the projectile is redirected to another nearby enemy after colliding, up to a number of times.
- Return: the projectile travels back toward its origin after reaching the end of its travel.
- Split: the projectile splits into several auto-targeting projectiles (highest priority; only once).
REFERENCE TABLE
What happens on a single collision
Priority the game uses at each collision. It checks behaviours top to bottom and applies the first one the projectile still has available. Only one line is used per collision.
| Step | On collision | What happens | Note |
|---|---|---|---|
| 1. Split | Projectile checks whether it can still Split | It splits into auto-targeting projectiles and the collision is consumed | Highest priority; a projectile can only Split once |
| 2. Pierce | If Split is exhausted, it checks Pierce | Passes through the target and keeps its original trajectory | Counts as a hit; does not change direction or speed; uses one Pierce count |
| 3. Fork | If neither Split nor Pierce applies here, it checks Fork | Splits into two projectiles at 60 and -60 degrees from the path | Only one fork unless Awakened Fork Support; a piercing hit does not fork |
| 4. Chain | If still nothing applied, it checks Chain | Redirects to another enemy within about 6 metres | Applied last among enemy-targeting behaviours; same enemy not hit twice in one Chain |
| 5. Return | If nothing else applies, or at end of travel | The projectile heads back toward its origin | Lowest priority; normally once; allows one extra hit on already-hit targets |
This priority is the global rule in Path of Exile 2. Specific skills or unique items can override part of it (for example forcing Fork before Pierce), so never assume a single skill's special case is the universal order.
REFERENCE TABLE
Behaviour pairing matrix
Which behaviours can combine, and how. 'Per collision' means on a single hit; several behaviours can still appear across the projectile's whole journey.
| Pairing | Possible? | Result |
|---|---|---|
| Pierce + Fork | Not on the same hit | Mutually exclusive per collision. A piercing projectile does not fork on that hit; Fork only happens once Pierce is used up (or never, if it pierces all targets). |
| Pierce + Chain (from enemy) | Not on the same hit | A projectile that can Pierce will not chain from enemies. It can chain from terrain after piercing. |
| Fork + Chain (from enemy) | Not on the same hit | Fork consumes the collision. After forked projectiles travel out, they may chain from terrain; enemy-chain follows only once their travel ends. |
| Fork + Return | Yes | Forked projectiles can Return toward the origin at the end of their travel. |
| Pierce + Return | Yes | After piercing, the projectile can Return. Some uniques require a pierce condition before Return triggers. |
| Chain + Return | Yes | Once the chain ends, Return can trigger and bring the projectile back. |
| Split + Pierce + Fork + Chain + Return | Yes (in priority order) | Split has top priority and can be followed by the rest in sequence across the projectile's full path. |
Shotgun prevention still applies: when several projectiles are created at once, only one may collide with the same target, so extra copies can pass through without hitting.
REFERENCE TABLE
Chain from enemy vs chain from terrain
Enemy-target Chain and terrain/object Chain are separate systems with different rules. Do not conflate them.
| Trigger source | Chains from | Notes |
|---|---|---|
| Enemy collision, projectile can Pierce or Fork | Does NOT chain from enemy | Only one behaviour per collision. If it pierces or forks, the enemy-chain is skipped. |
| Enemy collision, no Pierce/Fork left | Chains from enemy | Redirects to another enemy within about 6 metres; the same enemy is not targeted twice in one Chain. |
| Terrain, wall, or obstacle | Chains from terrain | By default only once unless otherwise stated. Chance to chain from terrain stacks additively. Can occur after piercing or forking an enemy. |
| Skill that cannot chain (e.g. Lightning Arrow) | Does NOT chain from terrain either | Some skills are forbidden from chaining entirely, including off terrain. This was fixed as a bug for Lightning Arrow in patch 0.2.0. |
Projectiles have a base chaining distance of about 6 metres; other (non-projectile) effects chain from about 4 metres.
REFERENCE TABLE
Worked examples
Qualitative cases showing how the priority order and target availability change the outcome. No exact numbers are stated because support values are version-sensitive.
| Case | Setup | Result |
|---|---|---|
| Straight line of mobs | Five enemies in a row; projectile has Pierce and Chain | The projectile Pierces through the line first (Pierce beats Chain). After Pierce is used up with no more enemies in the way, it may chain from terrain or simply end. Chain from enemies does not trigger while it can still Pierce. |
| Wall bounce | One enemy near a wall; projectile has % chance to chain from terrain | On hitting the enemy with no Pierce/Fork left, the projectile can chain off the wall to a second enemy. Terrain chain happens at most once by default and its chance is additive. |
| Boss, single target | One boss; projectile has Fork, Chain, and Return | With no other target nearby, Fork and Chain find nothing to redirect to and travel off. Return can add one extra collision against the boss (the only already-hit target), making Return the most useful of the four here. |
These are teaching examples of the priority system. Exact Pierce/Chain counts and damage come from the current in-game tooltip.
DIAGNOSTIC
Clear speed vs bossing
Pick the kind of encounter you are building for. The tool points to the supports that actually help.
OVERVIEW
Skills and items that forbid behaviours
Not every projectile skill can use all four behaviours. Some skills or items explicitly forbid one, and the rule is written in the skill or item text. Always read the tooltip before assuming a support will work.
In general, a behaviour is forbidden when the text says the projectile 'cannot Pierce / Fork / Chain / Return', or when the skill already has a built-in behaviour that blocks another (for example a skill that Pierces all targets cannot Fork on a hit it passes through).
- Lightning Arrow: cannot Chain, including off terrain (fixed as a bug in patch 0.2.0).
- Freezing Pulse: projectiles Pierce all targets, so they cannot Fork.
- Spectral Throw: projectiles Return and behave as piercing, so Fork does not apply on its hits.
- Some unique items (for example the Snakepit ring) prevent spell projectiles from Piercing or Chaining depending on the socket.
- Ascendancy or passive effects can also grant or remove a behaviour; the tooltip is the source of truth.
COMMON MISTAKES
Common mistakes
Most projectile problems come from misunderstanding the priority order and the single-behaviour-per-collision rule rather than from bad rolls. Watch for these before blaming the game.
- Chain 'not triggering': the projectile can also Pierce or Fork, so enemy-chain is skipped; or there is no valid enemy within the chain distance; or the skill cannot chain at all.
- Projectile 'disappears': it ran out of behaviours and travelled off. Fork and Chain need a valid secondary target, otherwise the projectile just expires at its travel limit.
- Return 'deals no damage': shotgun prevention means a returning projectile gets only one extra collision per set on already-hit targets; other returns pass through without colliding.
- Assuming every projectile skill supports all four behaviours — check the tooltip for 'cannot Pierce/Fork/Chain/Return'.
- Conflating enemy Chain with terrain Chain — they follow different rules and limits.
- Mixing up Fork (two at plus/minus 60 degrees) with Split (auto-targeting copies) and with Projectile Count (more separate projectiles).
CARD GRID
Common points of confusion
Paraphrased confusions players often raise about projectile behaviours.
Chain feels weak on bosses
Players expect Chain to add damage to a lone boss, but Chain needs another enemy to redirect to. On a single target it does almost nothing, which is the core point of the referenced video guide.
Why Chain Might Be Worse Than You ThinkPierce and Fork together
Many assume a gem can both Pierce and Fork on the same hit. Only one behaviour resolves per collision, so a piercing hit does not fork.
Lightning Arrow still chains
Some players believed Lightning Arrow could chain off terrain. Patch 0.2.0 fixed it so the skill cannot chain at all, including off terrain.
Return hitting the same enemy
Players are surprised a returning projectile hits an already-hit enemy again. Return uniquely allows one extra collision per set on targets already struck.
SCREENSHOTS & VIDEO
Video guide
Last Protagonist
PoE 2 - Why Chain Might Be Worse Than You Think [Patch 0.2]
A community breakdown of when Chain helps clear speed and when it wastes value on single targets, plus how projectile supports compare in Path of Exile 2.
What to watch for: Chain shines against packs but adds little to a lone boss; choose Fork/Chain for clearing and Pierce/Return for single targets based on the collision priority order.
Open source ↗PROBLEMS & ANSWERS
Frequently asked questions
Can every projectile skill use Pierce, Fork, Chain, and Return?
No. Some skills or items explicitly forbid a behaviour. Lightning Arrow cannot Chain (including from terrain), and Freezing Pulse Pierces all targets so it cannot Fork. Read the skill tooltip for 'cannot Pierce/Fork/Chain/Return'.
What is the priority order when a projectile collides?
The game checks Split, then Pierce, then Fork, then Chain, then Return. Only one of these behaviours occurs on a single collision, so the first one the projectile still has available wins.
Does Chain from enemies work the same as Chain from terrain?
No. If the projectile can Pierce or Fork, it will not chain from enemies, but it can chain from terrain afterward (and only once by default). Some skills cannot chain from terrain either.
Does Return hit the same enemy again?
Yes. Unlike the other behaviours, Return allows one extra collision per simultaneous set against targets that were already hit. A projectile normally Returns only once.
What is the base chain distance?
Projectiles chain from about 6 metres away; other (non-projectile) effects chain from about 4 metres. The same enemy is not targeted twice within one Chain.
Is Fork the same as Split or Projectile Count?
No. Fork makes two projectiles at 60 and -60 degrees. Split makes several auto-targeting copies. Projectile Count simply fires more separate projectiles. Shotgun prevention still stops multiple simultaneous projectiles from all hitting one target.
SOURCES & CHANGELOG
Sources and verification
Collision priority, behaviour definitions, shotgun prevention, and the 15-metre travel limit
Pierce behaviour, Pierce count, and interaction with Fork/Chain/Return
Fork behaviour, the 60/-60 degree split, and fork limits
Chain behaviour, enemy vs terrain chaining, and base chain distance
Return behaviour and the extra collision against already-hit targets
Community video on when Chain helps or hurts in Path of Exile 2
CHANGELOG
Changelog
- Initial publication of the projectile Pierce, Fork, Chain, and Return guide for Path of Exile 2 Early Access 0.5.4.
- Added direct answers, definitions, collision priority order, behaviour pairing matrix, enemy vs terrain chaining, worked examples, clear vs bossing diagnostic, skill exceptions, troubleshooting, community confusion, video, FAQ, and sources.
Information is compiled from public web sources and in-game observations; some visuals are original editorial diagrams. External information and images remain the property of their authors or platforms; contact us for removal requests.