The Buff Mechanics system in Remixed Dungeon handles all temporary status effects (buffs and debuffs) applied to characters. It is centered around the `Buff` base class and its various subclasses.

Core System:

• `com/watabou/pixeldungeon/actors/buffs/Buff.java` - Base class for all buffs and debuffs
• `com/watabou/pixeldungeon/actors/Char.java` - Character class that manages buff application
• `com/watabou/pixeldungeon/actors/buffs/Buff.java` - Contains duration, stacking, and application logic

Specialized Buff Base Classes:

• `com/watabou/pixeldungeon/items/rings/ArtifactBuff.java` - Base for artifact-sourced buffs (auto-detach on artifact removal)
• `com/watabou/pixeldungeon/actors/buffs/DurationBuff.java` - Base for time-limited buffs
• `com/watabou/pixeldungeon/actors/buffs/PermaBuff.java` - Base for permanent buffs

Buff Factory:

• `com/nyrds/pixeldungeon/mechanics/buffs/BuffFactory.java` - Central registry and factory for buff creation

Key Interfaces:

• `com/nyrds/pixeldungeon/mechanics/NamedEntityKind.java` - Entity identification for buff types
• `com/nyrds/pixeldungeon/utils/EntityIdSource.java` - Source ID tracking for artifact buffs

Duration System:

// In Buff.java
protected float duration;
public void set(float duration) { this.duration = duration; }
public float getDuration() { return duration; }
 
// Duration is reduced each turn in act()
@Override
public void act() {
    duration--;
    if (duration <= 0) detach();
}

Duration Factor:

// In Char.java / CharUtils.java
public static float durationFactor(Char ch) {
    // Returns factor based on character's resistances, etc.
}

Stacking Rules:

• Replace: New application replaces existing buff (default for most buffs)
• Extend: New application adds to duration
• Stack: Multiple instances can exist simultaneously (rare)
• Determined by buff class implementation in `attachTo()` method

Application Flow: 1. `Buff.affect(target, buffClass, duration)` - Factory method to create/apply buff 2. `BuffFactory.getBuff(buffClass)` - Gets or creates buff instance 3. `buff.attachTo(target)` - Attaches to character, handles stacking logic 3. `target.addBuff(buff)` - Adds to character's buff list

Removal:

• Automatic: Duration expires in `act()`
• Manual: `buff.detach()` or `target.removeBuff(buffClass)`
• Source-based: ArtifactBuff auto-detaches when source artifact removed

Buffs do not have separate JSON configuration files. They are:

• Defined entirely in Java code as subclasses of `Buff`
• Registered through `BuffFactory` at startup
• Associated with their source items/abilities via string resources

Each buff has string resources in `values/strings_all.xml`:

<string name="BuffClass_Name">Display Name</string>
<string name="BuffClass_Desc">Description of effect</string>

Localized versions exist in `values-<lang>/strings_all.xml` for each supported language.

Buffs are implemented entirely in Java. No Lua scripts are used for buff mechanics. Custom buff behaviors are implemented via Java subclassing.

Base System:

• Buff (Base Class) - Base buff implementation
• Artifact Buff - Artifact-sourced buff base class
• Charm Buff - Example charm mechanic buff

Status Effect Categories:

• Poison Buff - Damage over time
• Burning Buff - Fire damage over time
• Paralysis Buff - Action prevention
• Invisibility Buff - Stealth effect
• Regeneration Buff - Healing over time

Related Systems:

• Char - Character buff management
• Buff Factory - Buff creation and registry

• Java: Buff.java
• Java: Char.java
• Java: BuffFactory.java
• Java: ArtifactBuff.java
• Java: EntityIdSource.java