[Viste]

так по моему лучше будет

     // add bg to update list
     // This must be done here, because we need to have already invited some players when first BG::Update() method is executed
     // and it doesn't matter if we call StartBattleGround() more times, because m_BattleGrounds is a map and instance id never changes
-    sBattleGroundMgr.AddBattleGround(GetInstanceID(), GetTypeID(), this);
+    sBattleGroundMgr.AddBattleGround(GetInstanceID(), IsRandom ? BATTLEGROUND_RB : GetTypeID(), this);

вместо

+    bgTypeId = isRandom ? BATTLEGROUND_RB : bgTypeId;
+