> ## Documentation Index
> Fetch the complete documentation index at: https://v5.rpgjs.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Parameter Commands

> Level, experience, HP, SP, and parameter management for players.

# Parameter Commands

Level, experience, HP, SP, and parameter management for players.

## Members

* [Add custom parameters](#add-custom-parameters)
* [Add custom parameters](#add-custom-parameters)
* [All Recovery](#all-recovery)
* [All Recovery](#all-recovery)
* [Change Experience](#change-experience)
* [Change Experience](#change-experience)
* [Change Experience Curve](#change-experience-curve)
* [Change HP](#change-hp)
* [Change HP](#change-hp)
* [Change Level](#change-level)
* [Change Level](#change-level)
* [Change SP](#change-sp)
* [Change SP](#change-sp)
* [Experience for next level ?](#experience-for-next-level)
* [Experience for next level ?](#experience-for-next-level)
* [Get Param Value](#get-param-value)
* [Get Param Value](#get-param-value)
* [getParamValue](#getparamvalue)
* [parameters](#parameters)
* [Recovery HP and/or SP](#recovery-hp-and-or-sp)
* [Recovery HP and/or SP](#recovery-hp-and-or-sp)
* [Set final level](#set-final-level)
* [Set final level](#set-final-level)
* [Set initial level](#set-initial-level)
* [Set initial level](#set-initial-level)
* [Set Parameters Modifier](#set-parameters-modifier)
* [Set Parameters Modifier](#set-parameters-modifier)
* [setParameter](#setparameter)
* [WithParameterManager](#withparametermanager)

## Add custom parameters

Give a new parameter. Give a start value and an end value.
The start value will be set to the level set at `player.initialLevel` and the end value will be linked to the level set at `player.finalLevel`.

```ts theme={null}
const SPEED = 'speed'

player.addParameter(SPEED, {
    start: 10,
    end: 100
})

player.param[SPEED] // 10
player.level += 5
player.param[SPEED] // 14
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `method`
* Member of: `ParameterManager`
* Defined in: `IParameterManager`

### Signature

```ts theme={null}
player.addParameter(name,curve)
```

### Parameters

* `name`: `string`
* `curve`: `{ start: number, end: number }`

## Add custom parameters

Give a new parameter. Give a start value and an end value.
The start value will be set to the level set at `player.initialLevel` and the end value will be linked to the level set at `player.finalLevel`.

```ts theme={null}
const SPEED = 'speed'

player.addParameter(SPEED, {
    start: 10,
    end: 100
})

player.param[SPEED] // 10
player.level += 5
player.param[SPEED] // 14
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `method`
* Member of: `ParameterManager`

### Signature

```ts theme={null}
player.addParameter(name,curve)
```

### Parameters

* `name`: `string`
* `value`: `ParameterValue`

## All Recovery

restores all HP and SP

```ts theme={null}
import { Presets } from '@rpgjs/server'

const { MAXHP, MAXSP } = Presets

console.log(player.param[MAXHP], player.param[MAXSP]) // 800, 230
player.hp = 100
player.sp = 0
player.allRecovery()
console.log(player.hp, player.sp) // 800, 230
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `method`
* Member of: `ParameterManager`
* Defined in: `IParameterManager`

### Signature

```ts theme={null}
player.allRecovery()
```

## All Recovery

restores all HP and SP

```ts theme={null}
import { Presets } from '@rpgjs/server'

const { MAXHP, MAXSP } = Presets

console.log(player.param[MAXHP], player.param[MAXSP]) // 800, 230
player.hp = 100
player.sp = 0
player.allRecovery()
console.log(player.hp, player.sp) // 800, 230
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `method`
* Member of: `ParameterManager`

### Signature

```ts theme={null}
player.allRecovery()
```

## Change Experience

Changing the player's experience.

```ts theme={null}
player.exp += 100
```

Levels are based on the experience curve.

```ts theme={null}
console.log(player.level) // 1
console.log(player.expForNextlevel) // 150
player.exp += 160
console.log(player.level) // 2
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `property`
* Member of: `ParameterManager`
* Defined in: `IParameterManager`

### Signature

```ts theme={null}
{number} player.exp
```

### Default

```ts theme={null}
0
```

## Change Experience

Changing the player's experience.

```ts theme={null}
player.exp += 100
```

Levels are based on the experience curve.

```ts theme={null}
console.log(player.level) // 1
console.log(player.expForNextlevel) // 150
player.exp += 160
console.log(player.level) // 2
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `setter`
* Member of: `ParameterManager`

### Signature

```ts theme={null}
{number} player.exp
```

### Default

```ts theme={null}
0
```

## Change Experience Curve

With Object-based syntax, you can use following options:

* `basis: number`

* `extra: number`

* `accelerationA: number`

* `accelerationB: number`

* Source: `packages/server/src/Player/ParameterManager.ts`

* Kind: `property`

* Member of: `ParameterManager`

* Defined in: `IParameterManager`

### Signature

```ts theme={null}
{object} player.expCurve
```

### Default

````ts theme={null}
```ts
{
     basis: 30,
     extra: 20,
     accelerationA: 30,
     accelerationB: 30
}
````

````

## Change HP

Changes the health points
- Cannot exceed the MaxHP parameter
- Cannot have a negative value
- If the value is 0, a hook named `onDead()` is called in the RpgPlayer class.

```ts
player.hp = 100
````

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `property`
* Member of: `ParameterManager`
* Defined in: `IParameterManager`

### Signature

```ts theme={null}
{number} player.hp
```

### Default

```ts theme={null}
MaxHPValue
```

## Change HP

Changes the health points

* Cannot exceed the MaxHP parameter
* Cannot have a negative value
* If the value is 0, a hook named `onDead()` is called in the RpgPlayer class.

```ts theme={null}
player.hp = 100
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `setter`
* Member of: `ParameterManager`

### Signature

```ts theme={null}
{number} player.hp
```

### Default

```ts theme={null}
MaxHPValue
```

## Change Level

Changing the player's level.

```ts theme={null}
player.level += 1
```

The level will be between the initial level given by the `initialLevel` and final level given by `finalLevel`

```ts theme={null}
player.finalLevel = 50
player.level = 60
console.log(player.level) // 50
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `property`
* Member of: `ParameterManager`
* Defined in: `IParameterManager`

### Signature

```ts theme={null}
{number} player.level
```

### Default

```ts theme={null}
1
```

## Change Level

Changing the player's level.

```ts theme={null}
player.level += 1
```

The level will be between the initial level given by the `initialLevel` and final level given by `finalLevel`

```ts theme={null}
player.finalLevel = 50
player.level = 60
console.log(player.level) // 50
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `setter`
* Member of: `ParameterManager`

### Signature

```ts theme={null}
{number} player.level
```

### Default

```ts theme={null}
1
```

## Change SP

Changes the skill points

* Cannot exceed the MaxSP parameter
* Cannot have a negative value

```ts theme={null}
player.sp = 200
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `property`
* Member of: `ParameterManager`
* Defined in: `IParameterManager`

### Signature

```ts theme={null}
{number} player.sp
```

### Default

```ts theme={null}
MaxSPValue
```

## Change SP

Changes the skill points

* Cannot exceed the MaxSP parameter
* Cannot have a negative value

```ts theme={null}
player.sp = 200
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `setter`
* Member of: `ParameterManager`

### Signature

```ts theme={null}
{number} player.sp
```

### Default

```ts theme={null}
MaxSPValue
```

## Experience for next level ?

```ts theme={null}
console.log(player.expForNextlevel) // 150
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `property`
* Member of: `ParameterManager`
* Defined in: `IParameterManager`

### Signature

```ts theme={null}
{number} player.expForNextlevel
```

## Experience for next level ?

```ts theme={null}
console.log(player.expForNextlevel) // 150
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `getter`
* Member of: `ParameterManager`

### Signature

```ts theme={null}
{number} player.expForNextlevel
```

## Get Param Value

Read the value of a parameter. Put the name of the parameter.

```ts theme={null}
import { Presets } from '@rpgjs/server'

const { MAXHP } = Presets

console.log(player.param[MAXHP])
```

> Possible to use the `player.getParamValue(name)` method instead

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `property`
* Member of: `ParameterManager`
* Defined in: `IParameterManager`

### Signature

```ts theme={null}
{object} player.param
```

## Get Param Value

Read the value of a parameter. Put the name of the parameter.

```ts theme={null}
import { Presets } from '@rpgjs/server'

const { MAXHP } = Presets

console.log(player.param[MAXHP])
```

> Possible to use the `player.getParamValue(name)` method instead

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `getter`
* Member of: `ParameterManager`

### Signature

```ts theme={null}
{object} player.param
```

## getParamValue

Get the value of a specific parameter by name

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `method`
* Defined in: `IParameterManager`

### Signature

```ts theme={null}
getParamValue(name: string): number
```

### Parameters

* `name`: `string`

### Returns

The calculated parameter value

### Examples

```ts theme={null}
import { Presets } from '@rpgjs/server'

const { MAXHP } = Presets

// Preferred way (reactive)
const maxHp = player.param[MAXHP];

// Legacy way (still works)
const maxHp = player.getParamValue(MAXHP);
```

## parameters

Get or set the parameters object

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `property`
* Member of: `ParameterManager`
* Defined in: `IParameterManager`

### Signature

```ts theme={null}
{object} parameters
```

## Recovery HP and/or SP

Gives back in percentage of health points to skill points

```ts theme={null}
import { Presets } from '@rpgjs/server'

const { MAXHP } = Presets

console.log(player.param[MAXHP]) // 800
player.hp = 100
player.recovery({ hp: 0.5 }) // = 800 * 0.5
console.log(player.hp) // 400
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `method`
* Member of: `ParameterManager`
* Defined in: `IParameterManager`

### Signature

```ts theme={null}
player.recovery(params)
```

### Parameters

* `params`: `{ hp?: number, sp?: number }`

## Recovery HP and/or SP

Gives back in percentage of health points to skill points

```ts theme={null}
import { Presets } from '@rpgjs/server'

const { MAXHP } = Presets

console.log(player.param[MAXHP]) // 800
player.hp = 100
player.recovery({ hp: 0.5 }) // = 800 * 0.5
console.log(player.hp) // 400
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `method`
* Member of: `ParameterManager`

### Signature

```ts theme={null}
player.recovery(params)
```

### Parameters

* `{ hp, sp }`: `{ hp?: number, sp?: number }`

## Set final level

```ts theme={null}
player.finalLevel = 50
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `property`
* Member of: `ParameterManager`
* Defined in: `IParameterManager`

### Signature

```ts theme={null}
{number} player.finalLevel
```

### Default

```ts theme={null}
99
```

## Set final level

```ts theme={null}
player.finalLevel = 50
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `property`
* Member of: `ParameterManager`

### Signature

```ts theme={null}
{number} player.finalLevel
```

### Default

```ts theme={null}
99
```

## Set initial level

```ts theme={null}
player.initialLevel = 5
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `property`
* Member of: `ParameterManager`
* Defined in: `IParameterManager`

### Signature

```ts theme={null}
{number} player.initialLevel
```

### Default

```ts theme={null}
1
```

## Set initial level

```ts theme={null}
player.initialLevel = 5
```

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `property`
* Member of: `ParameterManager`

### Signature

```ts theme={null}
{number} player.initialLevel
```

### Default

```ts theme={null}
1
```

## Set Parameters Modifier

Direct parameter modifiers (reactive signal)

> It is important that these parameters have been created beforehand with the `addParameter()` method.
> By default, the following settings have been created:

* maxhp
* maxsp
* str
* int
* dex
* agi

**Object Key**

The key of the object is the name of the parameter

> The good practice is to retrieve the name coming from a constant

**Object Value**

The value of the key is an object containing:

```
{
  value: number,
  rate: number
}
```

* value: Adds a number to the parameter
* rate: Adds a rate to the parameter

> Note that you can put both (value and rate)

This property uses reactive signals - changes automatically trigger parameter recalculation.
The final parameter values in `param` include aggregated modifiers from equipment, states, etc.

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `property`
* Member of: `ParameterManager`
* Defined in: `IParameterManager`

### Signature

```ts theme={null}
{Object} [paramsModifier]
```

### Examples

```ts theme={null}
import { Presets } from '@rpgjs/server'

const { MAXHP } = Presets

// Set direct modifiers (reactive)
player.paramsModifier = {
     [MAXHP]: {
         value: 100
     }
}

// Parameters automatically recalculate
console.log(player.param[MAXHP]); // Updated value
```

## Set Parameters Modifier

Changes the values of some parameters

> It is important that these parameters have been created beforehand with the `addParameter()` method.
> By default, the following settings have been created:

* maxhp
* maxsp
* str
* int
* dex
* agi

**Object Key**

The key of the object is the name of the parameter

> The good practice is to retrieve the name coming from a constant

**Object Value**

The value of the key is an object containing:

```
{
  value: number,
  rate: number
}
```

* value: Adds a number to the parameter
* rate: Adds a rate to the parameter

> Note that you can put both (value and rate)

In the case of a state or the equipment of a weapon or armor, the parameters will be changed but if the state disappears or the armor/weapon is de-equipped, then the parameters will return to the initial state.

* Source: `packages/server/src/Player/ParameterManager.ts`
* Kind: `setter`
* Member of: `ParameterManager`

### Signature

```ts theme={null}
{Object} [paramsModifier]
```

### Examples

````ts theme={null}
```ts
import { Presets } from '@rpgjs/server'

const { MAXHP } = Presets

player.paramsModifier = {
     [MAXHP]: {
         value: 100
     }
}
````

1. Player has 741 MaxHp
2. After changing the parameter, he will have 841 MaxHp

````

## setParameter

Set a parameter with either a fixed value or a level curve

A numeric value is stored as a fixed parameter where `start === end`.

- Source: `packages/server/src/Player/ParameterManager.ts`
- Kind: `method`
- Defined in: `IParameterManager`

### Signature

```ts
setParameter(name: string, value: ParameterValue): void
````

### Parameters

* `name`: `string`
* `value`: `ParameterValue`

## WithParameterManager

Parameter Manager Mixin with Reactive Signals

Provides comprehensive parameter management functionality using reactive signals from `@signe/reactive`.
This mixin handles health points (HP), skill points (SP), experience and level progression,
custom parameters, and parameter modifiers with automatic reactivity.

**Key Features:**

* ✨ **Reactive Parameters**: All parameters automatically recalculate when level or modifiers change

* 🚀 **Performance Optimized**: Uses computed signals to avoid unnecessary recalculations

* 🔄 **Real-time Updates**: Changes propagate automatically throughout the system

* 🎯 **Type Safe**: Full TypeScript support with proper type inference

* Source: `packages/server/src/Player/ParameterManager.ts`

* Kind: `function`

### Signature

```ts theme={null}
WithParameterManager(Base: TBase)
```

### Parameters

* `Base`: `TBase`

### Returns

Extended class with reactive parameter management methods

### Examples

```ts theme={null}
class MyPlayer extends WithParameterManager(BasePlayer) {
  constructor() {
    super();
    
    // Add custom parameters
    this.addParameter('strength', { start: 10, end: 100 });
    this.addParameter('magic', { start: 5, end: 80 });
  }
}

const player = new MyPlayer();

// Reactive parameter updates
player.level = 5;
console.log(player.param.strength); // Automatically calculated for level 5

// Reactive modifiers
player.paramsModifier = {
  [MAXHP]: { value: 100, rate: 1.2 }
};
console.log(player.param[MAXHP]); // Automatically includes modifiers
```