Haunted Doors spawn randomly throughout the Queensdale, Kessex Hills and Gendarran Fields. Walk up to them and “Trick or Treat” monsters will spawn. These monsters drop Trick of Treat bags and count towards the achievement Halloween Hunting’, which you need to complete to get the “Emissary of the Mad King” title. If you didn’t complete this achievement yet, we believe these tips will help you:
 

1. Get on a high-ground. They have a massive visibility range, you can almost see their green glow from the other side of the map.
2. Use the “balanced” preset for graphics which allowed doors to render in the distance despite the rest of the landscape not being loaded
3. It’s far more effective to be in the group (try asking in map chat for a party). More people = more door opens = more kills and more bags
4. Bring your mesmer pals for ports and stack swiftness with whatever you have.
5. Gendarran Fields locations:
   • East of the northernmost Waypoint Provern Shore, It’s situated above a pirate cove, and there’s a heart vendor very close.
   • Near Broadhollow Waypoint
6. Queensdale Location:
   Shaemoor Fields has 4 spawn locations very close to each other, you can stand in one spot and see all of those spawn locations from there.