Playing on Nightmare difficulty changes everything about ghost interaction
The ghost will hunt more often, you'll have less gear, and the book becomes your most important tool because sanity drains faster than usual. Most players skip reading up on Nightmare and walk into their first session completely unprepared. I've been running campaigns on this difficulty for months now, and I can tell you the main issue isn't the ghosts themselves. It's how quickly you waste resources before identifying what you're dealing with. The Ghost Guidebook is found in the van at the start of every contract. You open it from your inventory and check the journal section. What it shows depends entirely on the evidence you've already collected. On Nightmare, you typically start with three ghost events before you can even narrow down the type, which means your first hour is usually just frantic equipment deployment and writing down observations. Here's what actually matters in practice. UV lights are your first move. Walk the ghost room and check door handles, closets, and drawers. Fingerprint marks show up as purple streaks. Don't bother cleaning them off or trying to trigger more. The ghost leaves new prints after each hunt cycle, so waiting is pointless. I once spent six minutes trying to get a clean UV photo of fingerprints on a window, and the ghost was in the walls the entire time. I missed a full ghost event during that whole sequence. Just photograph them and move on.
Spirit boxes are where most people on Nightmare make mistakes. The default question is too slow. I switched to using "Is there a spirit?" and "Show me a sign" on loop, and I listen for a response rather than typing every single prompt. A response on Nightmare comes through as a distorted whisper, usually lasting about half a second. You hear it clearly if you're wearing headphones and the volume isn't drowned out by the ghost's movement sounds. The mistake everyone makes is spamming questions while the ghost is actively haunting nearby. It won't answer during active events. Wait until the ghost goes into the idle wander state, then hit the box. Thermometers are deceptive on this difficulty. Cold spots show up as brief blue fog, but you won't see them on the thermal camera unless you're looking directly at the ghost's location. The in-game temperature drops 5 to 10 degrees in the ghost room. I learned this the hard way when I was chasing a phantom around the house watching thermometers and completely missed the temperature shift because I wasn't checking the room-specific reading. Put the thermometer on the desk in the ghost room and let it sit. Don't carry it around like it's going to teleport the cold spot to you. When you have three pieces of evidence, select the ghost in the book and confirm. Getting it wrong costs twenty minutes of sanity drain because the ghost becomes significantly more aggressive if you guess incorrectly. I've lost two full hunts in one session from wrong guesses on a Shadow and a Revenant, which look similar on paper if you only have EMF and dots as evidence.
Here's something most guides won't tell you: the ghost's favorite room doesn't change between difficulties, but on Nightmare it shifts more frequently. This means a ghost you initially find in the bedroom could be roaming the basement by the time you finish your evidence run. Track it by the sound of footsteps and door creaks, not by where you first saw it. The audio cues travel through walls on this difficulty, so you can triangulate the room without entering it. I use a notebook app to log each door creak location, and it helps me map the ghost's patrol route faster than relying on memory alone. Equipment recommendations for Nightmare: Bring a video camera alongside the guidebook. Ghost orbs are a visual clue you get free once you place the camera. Don't set it in the ghost room immediately though. Place it in the hallway or entryway first. The orbs appear randomly across the map, and having it closer to where the ghost moves between rooms gives you a better catch rate. Switch it to the ghost room only after you've ruled out other evidence types. The biggest bottleneck on Nightmare is time. You have limited supplies, and every failed equipment check costs sanity you can't recover without a crucifix or a medium's abilities. If you're running without a medium, you need to identify the ghost within the first forty-five minutes or the sanity drain makes the rest of the contract nearly unplayable. I've seen groups struggle past an hour on Nightmare with only one correct guess and it basically ended the match early. The ghost goes feral faster, hunts more frequently, and the equipment fails more often because low sanity breaks gear connections.
Get the Full Details

If you keep getting the wrong ghost type after collecting evidence, go back and verify your UV findings. Fingerprint types and ghost writing are the two clues people misread most often. Smudged prints are different from fresh ones. Ghost writing appears as text on paper or mirrors and it looks like scribbles until it stabilizes. Take a photo only when the writing is legible. I wasted three evidence slots once because I photographed half-finished ghost writing and counted it as a positive, which threw off my entire identification.