# Damage Formula

When selecting a potion item type or skill, you can input a **damage formula**. However, you can also use this field to execute other actions (e.g., awarding items, skills, or gold). Here's an explanation of how this works:

***

1. **`a` (attacker)**: Represents the entity initiating the action (e.g., player, NPC).
2. **`b` (defender)**: Represents the entity receiving the action (e.g., player, enemy).
3. **Both `a` and `b` are `ScriptUnit` objects.**
4. For **items**, `b` does not exist, and you can use `level` to get the item's level.
5. For **states**, only `a` and `b` exist.
6. For **skills**, `level` refers to the skill's level.

***

## **Variable**

<table><thead><tr><th width="280">Variable</th><th>Description</th></tr></thead><tbody><tr><td><strong>a.id</strong></td><td>a playerID</td></tr><tr><td><strong>a.type</strong></td><td>a Type (0=player, 1=event, 2=monster)</td></tr><tr><td><strong>a.name</strong></td><td>a Name</td></tr><tr><td><strong>a.x</strong></td><td>a position X</td></tr><tr><td><strong>a.y</strong></td><td>a position Y</td></tr><tr><td><strong>a.atk</strong></td><td>a Attack</td></tr><tr><td><strong>a.def</strong></td><td>a Defense</td></tr><tr><td><strong>a.magicAtk</strong></td><td>a MagicAttack</td></tr><tr><td><strong>a.magicDef</strong></td><td>a MagicDefense</td></tr><tr><td><strong>a.agi</strong></td><td> A gility</td></tr><tr><td><strong>a.luk</strong></td><td>a Lucky </td></tr><tr><td><strong>a.maxHP</strong></td><td>a maxHP</td></tr><tr><td><strong>a.maxMP</strong></td><td>a maxMP</td></tr><tr><td><strong>a.hp</strong></td><td>a currentHP</td></tr><tr><td><strong>a.mp</strong></td><td>a currentMP</td></tr></tbody></table>

## **Function**

<table><thead><tr><th width="333">함수</th><th>설명</th></tr></thead><tbody><tr><td><strong>a.SpawnAt(x, y)</strong></td><td>Move a to the coordinates x, y.</td></tr><tr><td><strong>a.SpawnAtField(mapID, x, y)</strong></td><td>Move a to the coordinates x, y on the map with ID mapID.</td></tr><tr><td><strong>a.RespawnAt(x, y)</strong></td><td>Teleport a to the coordinates x, y.</td></tr><tr><td><strong>a.SetVar(id, value)</strong></td><td>Change the variable with ID id of a to value.</td></tr><tr><td><strong>a.GetVar(id)</strong></td><td>Retrieve the variable with ID id from a.</td></tr><tr><td><strong>a.AddSkill(id, level)</strong></td><td>Add a skill with ID id and level level to a.</td></tr><tr><td><strong>a.AddItem(id, count)</strong></td><td>Add count items with ID id to a.</td></tr><tr><td><strong>a.AddGameMoney(amount)</strong></td><td>Add gold to a.</td></tr><tr><td><strong>b.RemoveSkill(id)</strong></td><td>Remove a skill with ID id from b.</td></tr><tr><td><strong>b.RemoveItem(id, count)</strong></td><td>Consume count items with ID id from b.</td></tr><tr><td><strong>b.UseGameMoney(amount)</strong></td><td>Deduct amount gold from b.</td></tr><tr><td><strong>b.StartGlobalEvent(id)</strong></td><td>Call the global event with ID id.</td></tr><tr><td><strong>b.AddBuff(id)</strong></td><td>Applies the state with the specified ID to b.</td></tr><tr><td><strong>b.RemoveBuff(id)</strong></td><td>Removes the state with the specified ID from b.</td></tr></tbody></table>

#### **Practical Examples**

**Damage Calculation Examples:**

1. **Basic Damage Formula**: Damage = Attacker's attack - Defender's defense

   ```css
   a.atk - b.def
   ```
2. **Random Damage**: Generates random damage between 10 and 50

   ```scss
   rand(10, 50)
   ```

**Custom Actions:**

3. **Steal Gold from Defender**:

   ```css
   b.UseGameMoney(10)
   ```
4. **Remove Items or Gold from Attacker**:

   ```css
   a.RemoveItem(1, 10) or a.UseGameMoney(10)
   ```

**Conditional Formulas:**

5. **Critical Damage Calculation**: Apply `(a.atk * 2)` for critical hits; otherwise, `(a.atk)`

   ```css
   critical and (a.atk * 2) or (a.atk)
   ```

**Skill-Specific Damage:**

6. **Damage Based on Skill Level**: Damage = `a.magicAtk - b.magicDef + level + 1`

   ```css
   a.magicAtk - b.magicDef + level + 1
   ```

**Item-Specific Actions:**

7. **Grant a Skill with an Item**: When using an item, grant `Skill ID 0` at `Level 1` to `a`

   ```css
   a.AddSkill(0, 1)
   ```

**State Effects:**

8. **Continuous Damage from States**: Apply 10 damage over time (minimum of 2 seconds)

   ```
   10
   ```