> For the complete documentation index, see [llms.txt](https://axiomemu.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://axiomemu.gitbook.io/docs/data/monster/monsterskillelement.md).
# MonsterSkillElement
Atomic building blocks for monster skills. Each Element defines one effect: damage/heal over a stat, a status change, a summon, a forced teleport, a buff nullification, and so on. Up to 5 Elements are chained inside a Skill Unit.
## File Location
```
Data/Monster/MonsterSkillElement.xml
```
Loaded once at GameServer startup. Changes require a restart.
## Dependencies
| Referenced by | Purpose |
| -------------------------------------------------------------- | --------------------------------------------- |
| [MonsterSkillUnit.xml](/docs/data/monster/monsterskillunit.md) | Each Unit chains up to 5 Elements by `Number` |
| Depends on | Purpose |
| -------------------------------- | --------------------------------------------------------------------------------------- |
| [Skill.txt](/docs/data/skill.md) | `NullifiedSkill` references skill indices (buff cancel, tether skill, paired effect id) |
## Schema
```xml
```
## Attributes
| Attribute | Type | Effect |
| ----------------- | ---------- | ---------------------------------------------------------------------------------------------------------------------------- |
| `Number` | int | Unique Element ID (0-99). Values outside this range are ignored. |
| `Name` | string | Human-readable label. Not used by logic. |
| `Type` | int | Effect category (see Effect Types). |
| `SuccessRate` | int | Percent chance the effect applies on hit (0-100). Rolled per target per Element. |
| `ContinuanceTime` | int | Duration in seconds for timed effects. `-1` or `*` means "indefinite" where the Type supports it. Ignored for instant Types. |
| `IncAndDecType` | int or `*` | Stat modifier mode (see IncAndDecType Values). `*` stores -1 (none). |
| `IncAndDecValue` | int or `*` | Magnitude paired with `IncAndDecType`. `*` stores -1. Also reused as a secondary parameter for some Types (see Type notes). |
| `NullifiedSkill` | int or `*` | Skill ID tied to the effect (buff to cancel, tether skill ID, or paired message ID). `*` stores -1. |
| `CharacterClass` | int | Loaded but not read by the skill pipeline. No class filter is applied. Keep `0`. |
| `CharacterLevel` | int | Loaded but not read by the skill pipeline. No level gate is applied. Keep `0`. |
## Effect Types
| Type | Name | Behavior |
| ---- | -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| 0 | Stun | Adds the stun effect for `ContinuanceTime` seconds. Blocked by Iron Defense buffs on the target. `SuccessRate` has the target's stun resistance subtracted before the roll. |
| 1 | Move | Placeholder. The handler is empty - no movement debuff is applied by this Type directly. |
| 2 | HP | Damage or heal based on `IncAndDecType`. Percent modes scale against current Life. Cycle modes write a periodic tick into the target for `ContinuanceTime` seconds. |
| 3 | MP | Same math as Type 2 against Mana. |
| 4 | AG | Same math as Type 2 against BP (AG). |
| 5 | Defense | Modifies the target's defense; value and duration are stored on the target and consumed over `ContinuanceTime`. |
| 6 | Attack | Modifies the target's physical damage; stored and consumed over `ContinuanceTime`. |
| 7 | Durability | Reduces durability on a randomly selected equipment slot (users only). |
| 8 | Summon | Respawns the target monster (the Element caller resurrects / repositions an allied monster). `IncAndDecValue` is the random placement radius (defaults to 10 if `*` or <0). |
| 9 | Push | If `NullifiedSkill` < 1, knocks the target back by `IncAndDecValue` tiles (default 3). Otherwise queues a delayed tether message with `NullifiedSkill` as the skill ID. |
| 10 | Stat Energy | Placeholder - handler is empty. |
| 11 | Stat Strength | Placeholder - handler is empty. |
| 12 | Stat Dexterity | Placeholder - handler is empty. |
| 13 | Stat Vitality | Placeholder - handler is empty. |
| 14 | Remove Skill | Strips a specific buff from the user. Supports Greater Damage and Greater Defense; `NullifiedSkill` must be that skill's ID. |
| 15 | Resist Skill | Stores a resist entry on the caster keyed to `NullifiedSkill` for `ContinuanceTime` seconds. |
| 16 | Immune Skill | Stores an immunity entry on the caster and applies a physical-damage immunity effect for `ContinuanceTime` seconds. |
| 17 | Teleport Skill | Teleports the caster to a random free tile within 5 tiles. Cancelled if caster is stunned or no valid tile exists. |
| 18 | Double HP | Queues two delayed self-messages 400ms and 1000ms out. Used for boss phase effects. |
| 19 | Poison | If `NullifiedSkill` < 1, adds poison for `IncAndDecValue` seconds (subject to target poison resistance). Otherwise queues a delayed message with `NullifiedSkill` as the skill ID and `IncAndDecValue` as the duration. |
| 20 | Normal Attack | Runs a melee attack against the target. If `IncAndDecType` / `IncAndDecValue` are set, acts as an item-gate: target is instantly killed unless item `GET_ITEM(IncAndDecType, IncAndDecValue)` is equipped in slot 9, 10, or 11. With `NullifiedSkill` >= 1, queues a delayed message instead of attacking. |
| 21 | Berserk | Applies monster physical and magical damage immunity for `ContinuanceTime` seconds (or indefinite if `-1`) and stores the berserk duration on the target. |
## IncAndDecType Values
Used by Types 2, 3, 4, 5, 6, 7 to decide how `IncAndDecValue` is applied. Cycle variants also set up a per-tick apply driven by `ContinuanceTime`.
| Value | Mode | Meaning |
| ----- | ----------------------- | ------------------------------------------------------- |
| 0 | None | No stat modification. Paired with `IncAndDecValue="*"`. |
| 1 | Percent Increase | Adds `IncAndDecValue` percent of the base stat. |
| 2 | Percent Decrease | Subtracts `IncAndDecValue` percent of the base stat. |
| 11 | Constant Increase | Adds `IncAndDecValue` flat. |
| 12 | Constant Decrease | Subtracts `IncAndDecValue` flat. |
| 100 | Cycle Percent | Periodic percentage change baseline. |
| 101 | Cycle Percent Increase | Periodic percent heal tick. |
| 102 | Cycle Percent Decrease | Periodic percent damage tick. |
| 110 | Cycle Constant | Periodic flat change baseline. |
| 111 | Cycle Constant Increase | Periodic flat heal tick. |
| 112 | Cycle Constant Decrease | Periodic flat damage tick. |
Any other value leaves the stat unchanged.
## Important Behavior
* Only 100 Element slots exist (`Number` 0-99). Entries outside this range are dropped silently.
* Stun resistance: for Type 0 the formula is `roll = rand(0..99); if roll > SuccessRate - ResistStunRate then fail`.
* `SuccessRate` is rolled independently per Element per target; a Unit with three Elements can partly succeed.
* `CharacterClass` and `CharacterLevel` are parsed but not consulted by the current pipeline. Do not rely on them as filters.
* `Name` is stored but never compared - any string works.
* Types 1, 10, 11, 12, 13 are stubs in the engine. Setting them has no effect.
* Types 14, 15, 16 use `NullifiedSkill` as the skill ID to cancel, resist, or immunize against.
* Type 20 (Normal Attack) doubles as a gear-check: fill `IncAndDecType` / `IncAndDecValue` with an ItemKind / Index pair to instakill players who do not have that item equipped in weapon or shield slots.
## Examples
{% tabs %}
{% tab title="Stun" %}
```xml
```
50% chance to stun the target for 3 seconds. Stun resistance reduces the roll.
{% endtab %}
{% tab title="Percent MP Drain" %}
```xml
```
50% chance to drain 50% of the target's current Mana. `ContinuanceTime` is only used when paired with a cycle `IncAndDecType`.
{% endtab %}
{% tab title="Poison over time" %}
```xml
```
Paired with a monster skill tether (NullifiedSkill 800). `IncAndDecValue` is the poison duration in seconds passed to the target.
{% endtab %}
{% tab title="Defense Debuff" %}
```xml
```
30% chance; applies a 10-point cycle decrease tick to Life over 10 seconds. Cycle constant decrease is a DoT.
{% endtab %}
{% endtabs %}
## Common Issues
* **Element never fires** - `SuccessRate` is rolled per target; low values combined with stun resist can drop effective chance to zero.
* **Stat Element has no effect** - the Type is one of the stub Types (1, 10-13). Pick a live Type.
* **"Nullify" does nothing** - Type 14 only handles Greater Damage and Greater Defense. Other buffs are not supported.
* **Push goes the wrong distance** - set `IncAndDecValue` to the tile count. Default is 3 tiles when `*` or <1.
* **Class filter not working** - `CharacterClass` / `CharacterLevel` are ignored by the pipeline. TODO: verify whether a future gate uses these.
* **Element number too high** - IDs must be 0-99. Higher numbers are dropped at load.