> 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/item.md).

# Item Configuration

The item configuration system controls how items are generated when they drop from monsters, are created through chaos mixes, or given through events.

See also: [Data overview](/docs/data/data.md) for sibling sections, and [Shop System](/docs/data/shop.md) for NPC shop inventories that reference these item definitions.

## Configuration Files

### Core Item Database

| File                                                              | Purpose                                                        |
| ----------------------------------------------------------------- | -------------------------------------------------------------- |
| [Item](/docs/data/item/item.md)                                   | Master item database (stats, requirements, classes)            |
| [ItemDrop](/docs/data/item/itemdrop.md)                           | Specific monster drop rules with full option control           |
| [ItemOptionRate](/docs/data/item/itemoptionrate.md)               | Probability tables for item options (level, skill, luck, etc.) |
| [ItemOption](/docs/data/item/itemoption.md)                       | Stat bonuses applied based on item options                     |
| [ExcellentOptionRate](/docs/data/item/excellentoptionrate.md)     | Which excellent bits apply to which item ranges                |
| [OptionIndex Reference](/docs/data/item/optionindex-reference.md) | Complete list of 75 stat effect types                          |

### Set Items

| File                                              | Purpose                          |
| ------------------------------------------------- | -------------------------------- |
| [SetItemType](/docs/data/item/setitemtype.md)     | Which items belong to which sets |
| [SetItemOption](/docs/data/item/setitemoption.md) | Set piece and full set bonuses   |

### Socket Items

| File                                                    | Purpose                                 |
| ------------------------------------------------------- | --------------------------------------- |
| [SocketItemType](/docs/data/item/socketitemtype.md)     | Which items can have sockets            |
| [SocketItemOption](/docs/data/item/socketitemoption.md) | Socket seed options and element bonuses |

### Enhancement Systems

| File                                                            | Purpose                                |
| --------------------------------------------------------------- | -------------------------------------- |
| [380ItemType](/docs/data/item/380itemtype.md)                   | Which items can have 380 enhancement   |
| [380ItemOption](/docs/data/item/380itemoption.md)               | 380 PvP option definitions             |
| [JewelOfHarmonyType](/docs/data/item/jewelofharmonytype.md)     | Item level requirements for JoH        |
| [JewelOfHarmonyOption](/docs/data/item/jewelofharmonyoption.md) | JoH bonuses for weapons, staves, armor |
| [LuckyItem](/docs/data/item/luckyitem.md)                       | Lucky item definitions and time decay  |

### Item Utility

| File                                      | Purpose                              |
| ----------------------------------------- | ------------------------------------ |
| [ItemStack](/docs/data/item/itemstack.md) | Stack sizes and transformation rules |
| [ItemValue](/docs/data/item/itemvalue.md) | Custom prices and currency types     |
| [ItemMove](/docs/data/item/itemmove.md)   | Trade/drop/sell/vault restrictions   |

## How Item Generation Works

When an item is created, the server:

1. **Determines the base item** - From drop tables or mix recipes
2. **Rolls for options** - Uses ItemOptionRate to determine level, skill, luck, etc.
3. **Applies option effects** - Uses ItemOption to set stat bonuses

```
Item Drop → ItemOptionRate (what options?) → ItemOption (what stats?)
```

## Key Concepts

### Option Rate Indices

Both ItemOptionRate and ItemOption use index values to categorize different drop or generation sources. Lucky items pull whichever indices are written into Option0-6 of the LuckyItem entry, so the index assignments below are a convention used by the shipping data files rather than hard-coded behaviour:

| Index | Convention             | Example                      |
| ----- | ---------------------- | ---------------------------- |
| 0     | Common monster drops   | Regular gameplay             |
| 1     | Excellent item drops   | Rare monster drops           |
| 2     | Set item drops         | Ancient items                |
| 3     | Chaos mix results      | Chaos Machine                |
| 9     | NPC merchant purchases | Moss Merchant - TODO: verify |
| 10    | Lucky item rolls       | Lucky Ticket chaos mix       |
| 11+   | Event item bags        | Specific event drops         |

### Rate Scale

All rates use a scale of **10000 = 100%**:

| Rate Value | Percentage |
| ---------- | ---------- |
| 10000      | 100%       |
| 7000       | 70%        |
| 500        | 5%         |
| 100        | 1%         |
| 10         | 0.1%       |

{% hint style="info" %}
Rates are **weighted random selection**, not cumulative. If you have Rate0=7000, Rate1=2000, Rate2=1000, the system picks one outcome with those relative weights.
{% endhint %}

## Common Customizations

### Making Items Rarer

Increase Rate0 (level 0) values and decrease higher level rates in ItemOptionRate.

### Creating Powerful Event Rewards

Use high-index EventItemBag entries (11+) with guaranteed high levels and options.

### Balancing Excellent Items

Adjust the ExcOptions section to control how many excellent options spawn on items.