> 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/monstersetbase.md).
# MonsterSetBase
Monster spawn locations, density, and respawn patterns
Controls where and how monsters spawn across all maps. The server scans one folder of per-map XML files at startup and appends every entry into a single global spawn table.
## File Location
**Per-map spawns:** `Data/Monster/MonsterSetBase/*.xml` (one file per map)
No master registry file ships with AXIOM-EMU. The server scans the `MonsterSetBase/` directory and loads every `.xml` file it finds.
{% hint style="info" %}
**Unified folder**: Castle Siege event maps (Castle Siege, Land of Trials, Crywolf, Barracks, Refuge, Loren Market) were historically split into a separate `MonsterSetBaseCS/` folder. That split is gone; everything lives in `MonsterSetBase/`. On non-Castle-Siege deployments, NPCs on CS-only maps still spawn but their interaction handlers self-gate, so they are inert.
{% endhint %}
## Dependencies
| Depends On | Purpose |
| -------------------------------------------- | ----------------------------------------------------------------------------- |
| [Monster.xml](/docs/data/monster/monster.md) | Spawns reference monster stats by Class (Index) |
| [MapManager.xml](/docs/data/mapmanager.md) | Entries on a map not enabled by this server are silently dropped at load time |
| Used By | Purpose |
| ------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Map loading | Server reads spawn files during map initialization |
| Event systems | Blood Castle, Devil Square, Illusion Temple, Imperial Guardian, Raklion, Crywolf, Castle Siege, Chaos Castle, and Invasion Manager all scan the spawn table for their Type 3 / Type 4 entries |
## File Structure
### Per-Map Spawn Files
Each map has its own file: `MonsterSetBase/000 - Lorencia.xml`, `MonsterSetBase/001 - Dungeon.xml`, etc. The filename is documentation only; the actual map is chosen by each entry's `Map` attribute. Files load in alphabetical order and their entries are appended into one global spawn table, so adding or renaming a file is all that is needed to register new spawns.
Map numbers match the game's internal map IDs (00 = Lorencia, 01 = Dungeon, 02 = Devias, etc.) and must match the Map value written inside each entry.
## Spawn Entry Attributes
| Attribute | Type | Description |
| --------- | ------ | ------------------------------------------------------------------------ |
| `Type` | int | Spawn type (see Spawn Types below) |
| `Class` | int | Monster Index from Monster.xml |
| `Map` | int | Map number (00 = Lorencia, 01 = Dungeon, etc.) |
| `Dis` | int | Roaming distance from spawn point (in tiles) |
| `X` | int | Spawn X coordinate |
| `Y` | int | Spawn Y coordinate |
| `TX` | int | Target X coordinate (Type 1/3 only) - defines spawn area with X |
| `TY` | int | Target Y coordinate (Type 1/3 only) - defines spawn area with Y |
| `Dir` | int | Facing direction (0-7, or -1 for random) |
| `Count` | int | Number of monsters to spawn (Type 1/3 only, minimum 1 if 0) |
| `Value` | int | Parsed but unused - no current system reads it. Leave it off new entries |
| `Comment` | string | Description (optional, for admin reference) |
## Spawn Types
| Type | Name | Behavior | Use Case |
| ---- | ----------- | ---------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------- |
| 0 | Fixed | Single monster at exact X/Y; respawns at the same location | NPCs, guards, stationary bosses |
| 1 | Group | Count monsters spawn randomly inside the (X,Y)-(TX,TY) rectangle; each respawn re-rolls a point in the same rectangle | Normal hunting zones |
| 2 | Spot | Single monster; loader offsets X/Y by -3..+3 once at load, then every (re)spawn picks a fresh point within +/-3 of that offset X/Y | Scattered individual spawns |
| 3 | Event | Parsed then skipped at map init; no system currently activates it. Do not use | None - see the warning below |
| 4 | Event Fixed | Single monster at exact X/Y; filtered out of normal init and activated by event code matching on MonsterClass and Map | Blood Castle, Devil Square, Illusion Temple, Imperial Guardian, Raklion |
### Type 0: Fixed Spawn
```xml
```
* Spawns exactly 1 monster at X=122, Y=110
* Dis="00" means the monster cannot roam
* Dir is a 0-7 facing index; use -1 for random
* Use for NPCs and bosses at specific locations
### Type 1: Group Spawn
```xml
```
* Spawns 7 spiders at (187,121) because TX=X and TY=Y (the spawn rectangle collapses to a single tile)
* TX/TY must be set larger than X/Y to create a real spawn area; otherwise every unit of `Count` spawns at the exact point
* `Dis="10"` allows each monster to roam 10 tiles from its spawn point
* `Dir="-1"` means random facing
* Use for normal monster packs in hunting zones
### Type 2: Spot Spawn
```xml
```
* Spawns 1 monster within a 7x7 box centered on the configured X/Y (coordinates offset by -3..+3 on each axis)
* The loader offsets the stored X/Y once at load time, then picks a fresh random point within +/-3 of that offset X/Y on every spawn and respawn
* Good for scattered individual monsters that should not cluster
* Commonly used in Noria for BeetleMonster and ForestMonster
### Type 3: Event Spawn (Invasion Manager)
```xml
```
{% hint style="danger" %}
**Type 3 rows never spawn in the current build.** They are filtered out of normal map initialisation, and nothing activates them afterwards - the `Value` attribute has no consumer. Rows like the example above load without error and then do nothing.
Invasions are configured entirely in `Data/Event/Invasions/*.xml` - see [Invasions](/docs/data/event/invasionmanager.md). Use Type 4 for event spawns that event code activates by class and map.
{% endhint %}
### Type 4: Event Fixed Spawn
```xml
```
* Single monster at exact X/Y for event systems
* Behaves like Type 0 but filtered by event code (Type 3/4 are excluded from normal spawns)
* Used by Blood Castle, Devil Square, Illusion Temple, Imperial Guardian, Raklion
* Event systems programmatically control when these spawns are activated
## Direction Values
| Dir | Meaning |
| --- | ------------------------------------------------------------- |
| 0-7 | Facing index (MU Online standard 8-way facing) |
| -1 | Random; loader rolls a fresh 0-7 value per entry at load time |
TODO: verify exact compass mapping of each 0-7 value against the client's direction table.
## Important Behavior
### Spawn Timing
{% hint style="info" %}
**Initial spawn**: All Type 0, 1, and 2 monsters spawn when the GameServer starts and loads maps. Type 3 and 4 entries are skipped during the normal spawn pass and are instantiated later by event systems on their own schedules.
**Respawn**: After death, monsters respawn based on their `RegenTime` in Monster.xml. The respawn location depends on spawn type:
* Type 0 / Type 4: exact same X/Y
* Type 1 / Type 3: fresh random point inside the (X,Y)-(TX,TY) rectangle
* Type 2: fresh random point inside +/-3 of the load-time offset X/Y (re-rolled every respawn)
{% endhint %}
### Coordinate System
* Coordinates are in tiles (not pixels)
* Origin (0,0) is typically top-left corner
* Maximum coordinates vary by map (usually 255x255 or similar)
* Invalid coordinates = monster spawns but is unreachable/invisible
### Dis (Roaming Distance)
* Dis="00" = Monster cannot move (stays at spawn point)
* Dis="10" = Monster can wander up to 10 tiles from spawn point before AI forces return
* Distance is calculated as Euclidean distance from spawn point (sqrt formula)
* Too high Dis on maps with walls = monsters may appear to walk through walls when returning
* NPCs should always have Dis="00" to prevent walking away
{% hint style="warning" %}
The roaming distance check uses the monster's current spawn point, not the original config X/Y. For Type 2, the spawn point is the randomized location rolled at spawn time, so the roam box travels with each respawn.
{% endhint %}
### Count Behavior
Type 1 and 3 spawn exactly `Count` monsters:
* `Count="007"` spawns 7 monsters
* `Count="000"` spawns 1 monster (the loader converts zero to one)
* Each monster rolls its initial location inside the (X,Y)-(TX,TY) rectangle
* On death, the respawn rolls a new location in the same rectangle (Type 1/3 only)
Internally the loader expands each Type 1 / Type 3 entry into `Count` individual spawn slots in the 20000-slot global table. A `Count="050"` entry consumes 50 slots.
### TX/TY as Spawn Area
For Type 1/3, (X,Y) and (TX,TY) define a rectangular spawn area:
* If `TX=X` and `TY=Y`, every unit of `Count` spawns at the exact point (the box collapses to a single tile). Use this only when you want stacked spawns
* If `TX` > `X` or `TY` > `Y`, spawns are spread across the rectangle (must be greater than, not just not equal)
* Example: `X="100" Y="100" TX="120" TY="120"` = 20x20 tile spawn zone
* The picker retries up to 100 times to find a walkable tile before giving up on that roll
### Event Spawn Filtering (Type 3/4)
{% hint style="info" %}
Type 4 spawns are **NOT included** in the normal monster spawn during map initialization. They are filtered out and only activated by event systems:
* **Type 4**: Blood Castle, Devil Square, Illusion Temple, Imperial Guardian, and Raklion use `MonsterClass` and `Map` to find specific spawns
Type 3 is filtered out in the same way but has no consumer, so those rows simply never spawn.
This allows event monsters to be defined alongside normal monsters without interfering with regular gameplay.
{% endhint %}
## Examples
{% tabs %}
{% tab title="NPC (Fixed)" %}
```xml
```
Spawns Trainer NPC at fixed location in Lorencia, cannot roam (Dis=0), facing index 3.
{% endtab %}
{% tab title="Monster Group" %}
```xml
```
Spawns 7 Bull Fighters at (201,69) with 10-tile roaming range, random facing. Because TX=X and TY=Y, all 7 start on the same tile before they roam apart.
{% endtab %}
{% tab title="Scattered Spawns" %}
```xml
```
Spawns 50 Spiders across an 80x100 tile zone (from 140,80 to 220,180), creating a dense hunting area.
{% endtab %}
{% tab title="Boss Spawn" %}
```xml
```
Spawns Gorgon boss at (125,125), can roam 5 tiles, facing index 0. Respawn time is controlled by Monster.xml RegenTime.
{% endtab %}
{% tab title="Event Spawn (Blood Castle)" %}
```xml
```
Defines a gate spawn for the Blood Castle event. Type 4 is filtered out of the normal map initialization spawn pass; Blood Castle finds it by scanning the spawn table for matching MonsterClass and Map.
{% endtab %}
{% tab title="Scattered Individual Monsters" %}
```xml
```
The loader offsets each entry's X/Y by -3..+3 once at load time. On every spawn and respawn the server rolls a fresh random point inside +/-3 of that offset X/Y, so each entry occupies a 7x7 tile box.
{% endtab %}
{% endtabs %}
## Per-Map Spawn Files
Each map has its own spawn file. The folder ships with files covering at least the following map IDs:
| Map ID | File | Map Name |
| --------- | ------------------------------------------------------------------------------------- | --------------------------- |
| 00 | `000 - Lorencia.xml` | Lorencia |
| 01 | `001 - Dungeon.xml` | Dungeon |
| 02 | `002 - Devias.xml` | Devias |
| 03 | `003 - Noria.xml` | Noria |
| 04 | `004 - Lost Tower.xml` | Lost Tower |
| 06 | `006 - Arena.xml` | Arena |
| 07 | `007 - Atlans.xml` | Atlans |
| 08 | `008 - Tarkan.xml` | Tarkan |
| 09 | `009 - Devil Square 1.xml` | Devil Square (lower tiers) |
| 10 | `010 - Icarus.xml` | Icarus |
| 11-17, 52 | `011 - Blood Castle 1.xml` ... `017 - Blood Castle 7.xml`, `052 - Blood Castle 8.xml` | Blood Castle |
| 18-23, 53 | `018 - Chaos Castle 1.xml` ... `023 - Chaos Castle 6.xml`, `053 - Chaos Castle 7.xml` | Chaos Castle |
| 24-29, 36 | `024 - Kalima 1.xml` ... `029 - Kalima 6.xml`, `036 - Kalima 7.xml` | Kalima |
| 30 | `030 - Castle Siege.xml` | Castle Siege |
| 31 | `031 - Land of Trials.xml` | Land of Trials |
| 32 | `032 - Devil Square 2.xml` | Devil Square (higher tiers) |
| 33 | `033 - Aida.xml` | Aida |
| 34 | `034 - Crywolf.xml` | Crywolf |
| 37-39 | `037 - Kanturu 1.xml` ... `039 - Kanturu 3.xml` | Kanturu |
| 40 | `040 - Silent.xml` | Silent Map |
| 41 | `041 - Barracks.xml` | Barracks of the Balgass |
| 42 | `042 - Refuge.xml` | Refuge of the Balgass |
| 45-50 | `045 - Illusion Temple 1.xml` ... `050 - Illusion Temple 6.xml` | Illusion Temple |
| 51 | `051 - Elbeland.xml` | Elbeland |
Kanturu 3 (map 39) also has dedicated spawn entries in [`KanturuMonsterSetBase.xml`](/docs/data/monster/kanturumonstersetbase.md) loaded separately for the Kanturu event.
{% hint style="info" %}
When adding spawns to a map, edit the corresponding map file (e.g., `000 - Lorencia.xml` for Lorencia spawns); there is no parent MonsterSetBase.xml file.
{% endhint %}
## Common Tasks
### Add Monster Spawn to Map
1. Find the map file (e.g., `002 - Devias.xml`)
2. Add a new `` entry
3. Set Type (usually 1 for monster groups)
4. Set Class to monster Index from Monster.xml
5. Set X/Y coordinates and Count
### Increase Monster Density
Find existing spawn entries and increase `Count`:
```xml
```
### Create Dense Hunting Zone
Add multiple spawn entries with overlapping areas:
```xml
```
Creates 45 Hell Hounds across overlapping zones for intense hunting.
### Remove Monster from Map
Delete or comment out the spawn entry:
```xml
```
### Move Boss Location
Change X and Y coordinates:
```xml
```
## Common Issues
{% hint style="warning" %}
**Monsters spawn inside walls.** Check that X/Y coordinates are on walkable terrain. Use in-game /move command to verify coordinates are valid.
{% endhint %}
{% hint style="warning" %}
**Count="000" spawns 1 monster, not 0** (only for Type 1/3). The code automatically converts Count=0 to Count=1. To disable a spawn, delete the entry or comment it out with ``.
{% endhint %}
{% hint style="warning" %}
**Changes don't appear immediately.** Monsters already spawned remain until they die. For immediate updates, restart the GameServer or use /reload commands if available.
{% endhint %}
{% hint style="info" %}
**Dis too high causes wall clipping.** If monsters appear to walk through walls, reduce their Dis value to keep them within the intended area. The pathfinding return-to-spawn logic can cause monsters to walk through obstacles.
{% endhint %}
{% hint style="warning" %}
**Type 2 spawns are not deterministic.** The loader rolls a -3..+3 offset on each restart, then every individual spawn and respawn rolls a fresh point inside +/-3 of that offset. Do not use Type 2 when you need a precise fixed location.
{% endhint %}
{% hint style="danger" %}
**Hard ceiling of 20000 spawn entries across all maps.** Each entry past the limit is silently dropped. For Type 1 the loader creates one spawn slot per unit of `Count`, so `Type="1" Count="050"` consumes 50 slots. On boot the GameServer logs `[MonsterSetBase] loaded N / 20000 entries`; if the cap is hit it also logs a red `[MonsterSetBase] CAP HIT - trailing spawn entries silently dropped` line. The ceiling is fixed in the build: reduce total spawn entries instead - lower `Count` on large Type 1 groups, or remove entries for maps this instance does not run. Vanilla S6 spawn data expands to \~10035 entries on its own; the previous 10000-slot limit silently dropped the tail of Arkania and any later map.
{% endhint %}
{% hint style="warning" %}
**Entries on disabled maps are dropped.** If the `Map` value belongs to a map this GameServer instance does not run (per [MapManager.xml](/docs/data/mapmanager.md)), the loader silently skips the entry instead of logging an error.
{% endhint %}
{% hint style="info" %}
**Per-map loading**: The server scans the `MonsterSetBase/` folder and loads every `.xml` file inside it into one global spawn table. There is no master registry file.
{% endhint %}
## Related Pages
* [Monster.xml](/docs/data/monster/monster.md) - Stats, RegenTime, and level for every Class referenced here
* [KanturuMonsterSetBase.xml](/docs/data/monster/kanturumonstersetbase.md) - Separate Kanturu-event spawn list for map 39
* [MapManager.xml](/docs/data/mapmanager.md) - Map index table controlling which maps this server actually runs