How to Spot Doppelgangers in Not A Customer: The Ultimate Guide

The only reliable way to spot doppelgangers in Not A Customer is to be ruthlessly thorough and trust your documents over your eyes. Even a 'perfect' doppelgänger with a flawless appearance will have at least one subtle error in their paperwork, a name missing from the daily visitor list, or will be exposed by a phone call to their apartment. Your checklist and resident files are your primary defense; visual tells are only for catching the sloppy impostors.

This guide breaks down every known method for identifying fake customers, from the blatantly obvious monsters to the nearly perfect mimics that require a detective's eye. Master these checks, and you'll survive the night.

01

Are They Visually... Wrong?tag

The first and most straightforward check is a simple visual scan. The lower-class, more desperate doppelgängers often fail to replicate human anatomy correctly. These are the easiest to spot and should be an immediate cause for hitting the emergency button. Don't even bother with their paperwork if you see any of the following traits.

Obvious Facial & Body Distortionstag

These are grotesque, clear-cut signs of a failed mimicry. The creature might get the general shape of a person right, but the details are a chaotic mess.

• Eye Anomalies: Look for a single large eye (a Cyclops), too many eyes scattered across the face, or eyes that are unnaturally large and black.
• Feature Misplacement: A nose where an ear should be or a mouth on their neck are dead giveaways.
• Melting or Unstable Features: The face might appear to be drooping like wax, with a mouth stretched impossibly wide or a nose that's just a gaping hole.
• Extra Limbs: A third arm, extra fingers, or other anatomical impossibilities are a sure sign you're not dealing with a human.
• Floating Parts: Sometimes their mimicry glitches, causing features like eyebrows or even a whole mouth to float slightly off the face.

Subtle Appearance Mismatchestag

More advanced doppelgängers will look perfectly human at a glance, but their appearance won't match the official records for the resident they're impersonating. This is why you must always compare the person at your window to the photo in their resident file, not the photo on their ID.

• Missing or Extra Details: The file says they have a mole above their left eye, but the person in front of you doesn't. The file photo shows no hat, but they are wearing one. These small details are critical.
• Incorrect Physical Traits: The file lists specific traits like 'long nose' or 'oval face'. If the person's features contradict the file, deny them. Even if the doppelgänger looks normal, if they don't look like the correct normal, they're a fake.

02

Is Their Paperwork Flawless?tag

Many doppelgängers can create a convincing physical disguise but fail when it comes to forging documents. Scrutinize every piece of paper they hand you. Even a single, tiny error is enough justification to call in the D.D.D. (Doppelgänger Detection Department).

Checking the ID Card & Entry Requesttag

Never trust documents at face value. Compare every detail against the information in your official resident folders.

1. Cross-Reference the ID Number: Pull up the resident's file and compare the ID number on the card to the one in your records. Fakes often change just one digit.
2. Verify the Expiration Date: The game is set in 1955. If an ID is expired (e.g., dated 1954) or has a future date, it's a forgery.
3. Inspect the D.D.D. Logo: Look closely at the official D.D.D. shield logo. Forgeries might have a mirrored version, a typo in the letters (like 'D.D.P.'), or use a slightly different font.
4. Confirm Profession: If the Entry Request form lists a profession, check it against their resident file. A doppelgänger might list the wrong job, sometimes even stealing the profession of another neighbor.
5. Check for Missing Documents: If they fail to present either their ID or their Entry Request form and make an excuse, it's an almost certain sign of a doppelgänger.

The Ultimate Test: The Daily Guest Listtag

This is your most powerful tool. A person can look perfect and have flawless documents, but if they are not on the guest list for that day, they are a doppelgänger trying to bluff their way in.

Always ask if they are on the list. Sometimes, a doppelgänger who is on the list won't know it and will react angrily, revealing themselves. If they aren't on the list, question them. While a real resident might have a valid reason (like an emergency at work), this should put you on high alert. Trust the list above all else.

03

What If Everything Looks Perfect?tag

This is the most dangerous scenario. You'll encounter 'perfect' mimics that have no visual flaws and have forged impeccable documents. In these cases, you need to rely on a final, definitive verification step.

The Decisive Phone Calltag

Your phone is your lifeline. If a person is at your window but you have even the slightest suspicion, call their apartment.

• If the real resident answers the phone: The person at your window is a doppelgänger. Hit the emergency button immediately. This is the most foolproof method for exposing even the most advanced fakes.
• If a roommate answers: You can gather valuable information. Ask if the resident they live with is home.
• If no one answers: This suggests the person at your window is likely the real resident returning home.

Always make this call if you're uncertain. It's better to be cautious and follow protocol than to let a predator into the building. Even if they live alone, call their number. If the phone picks up, you've found your impostor.

04

Advanced Tactics and Behavioral Tellstag

Beyond the core mechanics, there are subtle behaviors and advanced strategies you can use to trip up a doppelgänger.

The Red-Handed Catchtag

Some doppelgängers are so confident in their disguise that they become flustered or aggressive when questioned about a flaw. This is known as catching them 'red-handed'.

If you point out a clear error (e.g., "You're not on the list," or "Your ID is missing a photo"), a red-handed doppelgänger will often break character, their form might shift into something more monstrous, and they'll give a hostile, revealing response. Intentionally questioning a flaw, even if you're bluffing, can sometimes provoke this reaction and earn you the 'Catch You' achievement.

Subtle Behavioral Cuestag

While not a primary method, some players report that doppelgängers occasionally exhibit strange behaviors.

• Odd Responses: They might hesitate or give strange, non-human answers to simple questions.
• Unnatural Movement: Their animations can sometimes appear robotic or slightly 'off'.
• Staring: They might avoid eye contact or stare with an unnerving intensity.

These cues are secondary to hard evidence like document errors but can reinforce your suspicion when something feels wrong.

05

Frequently Asked Questionstag

Here are quick answers to the most common questions about spotting doppelgängers.

What's the single most reliable way to spot a doppelgänger? The phone call. If someone is at your window and the person they claim to be answers the phone in their apartment, you have irrefutable proof of a doppelgänger.

Do I need to check everything on the checklist? Yes, especially in the harder difficulties. Being thorough is the only way to guarantee an S-Rank and avoid mistakes. Don't skip any steps. Completing the checklist is primarily for your benefit, to ensure you haven't missed a detail.

What if a real person isn't on the visitor list? This can happen. A real resident might have had a work emergency or forgotten to sign up. In this case, you must rely on all other checks—appearance, documents, and the phone call—to verify their identity. Their absence from the list is a major red flag, but not automatic proof of a doppelgänger.

Can doppelgängers have perfect IDs? Yes. Higher-level doppelgängers can forge documents with no errors. That's why you can't rely on just one method. You must use the visitor list and the phone call as your ultimate arbiters when paperwork seems correct.

06

Final Shift Thoughtstag

Surviving your job in Not A Customer is less about quick reflexes and more about methodical, cold-hearted bureaucracy. Your desk is your fortress, and your procedures are your weapons. Every visitor is a potential threat, and your job is to assume they are fake until proven otherwise. Trust the process, check every detail, and never, ever get complacent. The moment you skip a step is the moment you become the next victim.