Implement D&D 5e condition system

[FirebrickRed]

Overview

Implement conditions (Blinded, Charmed, Deafened, Frightened, Grappled, Incapacitated, Invisible, Paralyzed, Petrified, Poisoned, Prone, Restrained, Stunned, Unconscious) with both manual DM application and automatic spell/ability triggers.

Two Implementation Paths

Path 1: Manual DM Commands (Easier - Phase 1)

Commands for DMs to manually apply/remove conditions:

• /condition apply <player> <condition> [duration]
• /condition remove <player> <condition>
• /condition list <player> - Show active conditions
• /condition clear <player> - Remove all conditions

Examples:

• /condition apply Alice frightened 3 - Apply frightened for 3 rounds
• /condition apply Bob paralyzed - Apply paralyzed indefinitely
• /condition remove Alice frightened

Path 2: Automatic Application (Harder - Phase 2)

Spells and abilities automatically apply conditions:

• Spell casting triggers condition application
• Racial abilities check for conditional advantages
• Combat system enforces condition effects

Examples:

• Casting Hold Person automatically applies paralyzed condition
• Racial trait "advantage vs frightened" checks if character has frightened condition
• Attacking paralyzed creature grants advantage automatically

Condition Effects to Track

Each condition has mechanical effects:

• Blinded: Disadvantage on attacks, attacks against have advantage
• Charmed: Can't attack charmer, charmer has advantage on social checks
• Frightened: Disadvantage on checks/attacks while source visible, can't move closer
• Paralyzed: Incapacitated, can't move/speak, fails STR/DEX saves, attacks have advantage, crits within 5ft
• Poisoned: Disadvantage on attacks and ability checks
• Etc.

Integration Points

• Racial traits use conditions (e.g., Brave: advantage vs frightened)
• Spell effects apply conditions (e.g., Hold Person: paralyzed)
• Combat system enforces condition effects (advantage/disadvantage)
• Character sheet displays active conditions

Data Model

public class Condition {
    String type;  // frightened, paralyzed, etc.
    int duration;  // -1 for indefinite, or number of rounds
    String source;  // spell name, ability name, or "DM"
    UUID appliedBy;  // UUID of caster/DM
}

// In CharacterSheet
private List<Condition> activeConditions = new ArrayList<>();

Related Issues

• Issue Implement racial innate spellcasting and abilities #51: Racial traits reference conditions (conditional_advantages)
• Issue Rest Request/Approval System #45: Rest system should clear certain conditions

Acceptance Criteria

Phase 1 (Manual):

• DM commands to apply/remove conditions
• Conditions persist on character sheet
• Conditions display in character sheet UI
• Conditions saved/loaded with character

Phase 2 (Automatic):

• Spell casting can apply conditions
• Racial traits check conditions for advantages
• Combat system enforces condition effects
• Duration tracking (round-based countdown)