The fall season has been in session for three weeks now, and while some shows are already getting canceled—I’m looking at y'all, The Playboy Cluband Free Agents—other shows have yet to premiere. This month, a wave of horror/sci-fi shows will join the season and make their mark on your fall viewing schedule. Here’s a glimpse at four supernatural shows premiering this month:

American Horror Story – FX – premiered Oct. 4 – Wednesdays 10/9c

Story: American Horror Story tells the tale of a family from Boston who moves into a seemingly haunted Los Angeles mansion, where the previous owners died in a murder-suicide. Psychotic patients, creepy neighbors and a whole lot of scares ensue. Connie Britton (Friday Night Lights) and Dylan McDermott (The Practice) star. Ryan Murphy (Nip/Tuck, Glee) executive produces.

What the critics are saying: The series may be one of the scariest things on television right now, but just because it’s the scariest doesn’t mean audiences will necessarily connect with it. TV Critics like Ed Martin have been discussing whether or not a series like this, one which he says “fits so squarely in the horror genre,” can survive on television. The series will offer “all scare, all the time,” as Ken Tucker from Entertainment Weekly put it. All scares can sometimes be bad, though — some critics have pointed out that the show is full of horror movie clichés and leaves little to no room for depth.

The difference: American Horror Story has been described as sadistic, violent and a psychosexual thriller. It’s not for the faint of heart, but if you’re interested in haunted house stories, this one is for you.

The Walking Dead – AMC – premieres tonight (Oct. 16) – Sundays 9/8c

Story: The Walking Dead is what you would expect from a typical zombie apocalypse story and then some. Officer Rick Grimes (Andrew Lincoln) wakes from a coma to find his whole town deserted, except for these odd disfigured humans (zombies) roaming the streets. He later finds a group of people who have managed to survive — a group that includes his wife and son — and together they set off to find other survivors, all while trying to survive themselves. The Walking Dead is based on the popular comic book series of the same name.

What critics are saying: While The Walking Dead isn’t a brand new show, the second season will, in a sense, be like a brand new series. Just as the first season ended, it was reported that the entire writers staff would be fired, and even more recently, the original showrunner, Frank Darabont, was let go in a controversial series of events that involved disputes between Darabont and AMC executives. The newest showrunner, Glen Mazzara, along with executive producer Robert Kirkman (the creator of the original comic) promise this season will be “a much bigger season than the first season.”

The difference:The Walking Dead focuses more on zombies and less on any other supernatural entity out there. The show, at its core, tells a powerful story of human survival. Gore, zombies and intense action is what will set this show apart from the others.

Once Upon a Time – ABC – premieres Oct. 23 – Sundays 8/7c

Story: Once Upon a Time is less fright and more fantasy. The show follows Emma Swan (Jennifer Morrison), who happens to be the daughter of Snow White (Ginnifer Goodwin) and Prince Charming (Josh Dallas). There’s only one problem — Emma has no clue about her real identity, and all the people in the town of Storybrooke are unaware they are characters from fairy tales, as well. They were all banished to the town by the evil queen some years ago, and it’s up to Emma to free them all.

What critics are saying: E!’s Kristin Dos Santos claims “The characters are intriguing in both worlds,” and chose this series as one of the top five to watch this fall. She also goes on to characterize the show as a mix between Lost and Pushing Daisies, which makes sense, seeing as the series was created by two former Lost writers.

The difference:Once Upon a Time seems to be your more traditional fairy tale show. What’s interesting about this show is that there are two universes that viewers are pulled into — one that takes place in modern-day Storybrooke and one that takes place in another world, where fairy tale characters exist in the flesh. Seeing these characters come to life will be half the intrigue.

Grimm – NBC – premieres Oct. 28 – Fridays 9/8c

Story:Grimm has shown up here at CultureMap before — I included the show in my “The 10 new TV shows to check out this fall” — and I still stand by that claim, despite what critics have been saying. Grimm focuses on homicide detective Nick Burkhardt. In the first episode, he learns he is descendant from a group of hunters known as “Grimms,” destined to protect humanity from the evil creatures that come straight from the Brothers Grimm fairytales. These creatures pose as everyday human beings, and only Grimms are able to see their true forms.

What critics are saying: Unfortunately, Grimm is one of the shows critics don’t believe will last this season. Friday night has already become a night of sci-fi, with Fringe on FOX and Supernatural on the CW, and critics just don’t think there's any room for Grimm to find an audience. Seeing as this is one of the few pilots I have been able to see before its premiere, I hope they predict wrong.

The difference:Grimm seems like it will follow a monster-of-the-week formula with a small dose of backstory for the lead character. In that sense, it will be more like a detective show mixed with fairy tale elements.

To recap, American Horror Story and The Walking Dead are a lot heavier, with the horror, gore and explicit content. Those shows are on cable networks, so that explains that. If you’re looking for a good haunted house-centric series, go with American Horror Story. If you’ve ever wondered what you would do in the event of a zombie apocalypse, check out The Walking Dead.

On the flip side, Once Upon a Time and Grimm are on broadcast networks, meaning their explicit content factor goes down remarkably. Once Upon a Time appeals to viewers who are looking to escape into fantasy, and it will be fun to watch to see how they bring fairy tale characters to life. Grimm plays more like a procedural cop show with a supernatural mythology. The fairy tale characters in this show won’t be as fantastical as the ones in Once Upon a Time, but they are a lot darker and grittier.

Tell us: Which supernatural series are you going to be tuning in for?