If you're here, then chances are you've just begun playing and have wondered what you're supposed to be doing (or perhaps how to keep yourself from dying). Or maybe you haven't begun playing yet and are wondering where to start. Maybe, you are trying to help someone else. Any reason you're here, we've got you covered.
How to Use This Guide
This guide should help turn a person with no knowledge of wining the game into an expert! Be aware that many things are not mentioned. This is more of a casual guide, and does not even gloss over some of the game's more hidden mechanics. If you are trying to go for 100% completion and collection of all Books and Memos, there are other guides here.
Note that this guide starts from Judgment Boy onward. Neko Zombie's and Catherine's souls are considered a 'tutorial' area as you have no Mental Gauge and can't die, so it is unnecessary to cover them here.
Sometimes, there are multiple ways to obtain a certain soul. These will be distinguished by Method (A) or Method (B), with A being the easier option.
If you spy on Catherine or Judgment Boy, at least one of them will mention how Gregory is acting 'strange' or 'troubled'. Catherine will also mention how someone has sneaked into her room. James will laugh about how he hid something from his grandfather. Spy on Gregory himself and you will notice he is desperate and frantically looking for something.
What he is looking for is the Dirty Book. You can find it in Room 104, Catherine's room, in front of the bed. It is recommended that you get the book from 4AM-3PM or 6PM-8PM, as these are times when she is on the east side of the hotel, away from her room and not walking through the halls.
Once you have obtained the book, speak with Gregory with the Dirty Book as your active Key Item. He will take the book, embarrassed, and tell you to find a more "tasteful" book in the Library. On the Library's central shelf, look for a distinctly red book. This is the Self-Help Book.
Once you have the Self-Help book, simply find and speak to Judgment Boy with the book as your active Key Item. He will ask you a question about surviving in the hotel. Simply answer "Just try and stop me!". He will drop the dollar sign, and give you his soul.
After Night 1, souls can be obtained in any order. Although, it is recommended that you take the souls in the order they are in from this guide. This is to prevent
Cactus Girl, when explaining knocking, says not to do it near her brother as he's a fugitive from the law and gets jumpy from knocks. To obtain Gunman's soul, you must knock 3 times on the door in the room he's currently in without him noticing you. He will run away, and in his fear, drop his soul.
At 2AM-4AM, Gunman is watching a western in the Lounge. Meanwhile, Catherine is sleeping and Mummy Dog and Mummy Papa are having a chat in their room. No one else is around at this time, making it the perfect moment to steal his soul.
If you didn't get his soul at 2AM-4AM on the Ground Floor, Catherine will either be around Gunman or make her rounds in the hallways. So, the next safest time would be when he is in the First Floor's Bar at 8AM-11AM. No one is around to catch you.
Note that he doesn't always go to the bar at this time. If it is a special action occurrence day, he will instead go to the Courtyard. If this happens, then you can go for his soul when he is in his room at 2PM-7PM or 10PM-1AM. Note that if you do opt for knocking on his room's door instead, you need to be weary of Lost Doll if you've taken her soul already.
Lost Doll's soul is always located in her room. Not only that, but she is guarding her room most of the time. Even if you try to enter the room when she goes to the courtyard at 7PM-10PM, it is locked and the dialogue says "The door is held tightly shut by the force of Lost Doll's spite."
Therefore, to obtain her soul, you must get a her a Doll. These are purchased at the Gregory Horror Shop for 5 stars. Once you've gotten the doll, simply switch it to your active key item and place it in front of Lost Doll. She will be distracted for 1 in-game hour. Use that small time frame to get into her room and take the soul.
Mummy Papa/Mummy Dog
Mummy Papa holds the soul. However, Mummy Dog will usually take it instead if Mummy Papa has passed out near him. Mummy Dog can also take the soul back if you are still holding it and he catches you in a Horror Show.
At 11PM-12AM, he passes out in the Library. Mummy Dog isn't around to help, so simply take the soul off of the ground. This method is simply the best, as Catherine, Lost Doll, and Cactus Gunman are at the First Floor and the Library is right next to the Save Room.
At 1PM-3PM, he and Mummy Dog are sleeping in their room. If you are quiet enough by walking slowly, you can take it from them as it's on the ground between their beds. If you mess up, they will wake up and run away, taking the soul with them.
Alternatively, at 3PM-5PM, Mummy Papa faints in the room. Strangely, Mummy Dog doesn't pick up the soul. Simply go into the room. It will scare Mummy Dog away, and the soul is on the ground, free for the taking. Just be careful going back to your room, as Mummy Dog can steal the soul back if you run into him.