allow to duel on map Core file edit >no need edit dbc file< (without dbc)

[Wise]

1-open file spellEffect.cpp
2- find this :

    // Players can only fight a duel in zones with this flag
    AreaTableEntry const* casterAreaEntry = GetAreaEntryByAreaID(caster->GetAreaId());
    if (casterAreaEntry && !(casterAreaEntry->flags & AREA_FLAG_ALLOW_DUELS))
    {
        
        SendCastResult(SPELL_FAILED_NO_DUELING);            // Dueling isn't allowed here
        return;
    }

    AreaTableEntry const* targetAreaEntry = GetAreaEntryByAreaID(target->GetAreaId());
    if (targetAreaEntry && !(targetAreaEntry->flags & AREA_FLAG_ALLOW_DUELS))
    {
        SendCastResult(SPELL_FAILED_NO_DUELING);            // Dueling isn't allowed here
        return;
    } 

3-edit to this

    // Players can only fight a duel in zones with this flag
    AreaTableEntry const* casterAreaEntry = GetAreaEntryByAreaID(caster->GetAreaId());
    if(caster->GetAreaId() != 3217){  //3217 is dire maul PVP
    if (casterAreaEntry && !(casterAreaEntry->flags & AREA_FLAG_ALLOW_DUELS))
    {
        
        SendCastResult(SPELL_FAILED_NO_DUELING);            // Dueling isn't allowed here
        return;
    }}

    AreaTableEntry const* targetAreaEntry = GetAreaEntryByAreaID(target->GetAreaId());
    if(target->GetAreaId() != 3217){  //3217 is dire maul PVP
    if (targetAreaEntry && !(targetAreaEntry->flags & AREA_FLAG_ALLOW_DUELS))
    {
        SendCastResult(SPELL_FAILED_NO_DUELING);            // Dueling isn't allowed here
        return;
    }} 

4-save and compile your source )