The recent announcement of Scooby-Doo! Curse of the 13th Ghost has caused a little spark in the Scooby fandom. I've noticed that now in several places, including in the comments here, fans have begun questioning how exactly one would properly categorize the Scooby franchise into timelines.
Personally, the following is how I view the Scooby-Doo timeline.
The following series fall under the "main" timeline. The main timeline encompasses all Scooby series, and are a part of the general fandom continuity. The following three series are pretty much compatible with every single timeline.
Scooby-Doo, Where Are You?
Arguably, the original series falls in the main timeline and chronology of the franchise. The gang is just a group of normal teenagers solving mysteries in this particular series.
The Scooby-Doo Show
While this show is a bit darker, it still falls under the general premise of the gang being normal teens capturing masked criminals. No real monsters appear in this series. Generally speaking, it's basically an extension of Scooby-Doo, Where Are You?.
The Scooby-Doo and Scrappy-Doo Show
While this show introduces Scooby's nephew, Scrappy, the show still takes on the same premise as the previously listed two, and there is no supernatural beings in this particular show. I should also note that I'm referring to only the original 1979-1980 series here, which included the gang.
#1: Fame and Fortune!
From this point on, everything connects to the main timeline, but the continuity branches off in a different direction for each extended timeline. If it's less confusing, think of the main timeline as the starting point for all the extended timelines. From there, each extended timeline branches off on its own.
I think it was my friend Dallas, whom I worked on the Scooby-Doo Chronological Viewing Order with, that came up with the "Fame and Fortune" era idea. After talking with some people about this topic this afternoon, I'm minded to agree that it's a bit unlikely that Scooby and the gang would be suddenly best friends with famous celebrities in certain series.
So, just for fun, let's say this timeline is the "Fame and Fortune" era.
Reader's note: To avoid confusion, that project is completely separate from this post. That timeline is just for the purposes of if you wanted to watch the franchise in the least confusing order.
The New Scooby-Doo Movies
The gang meets several celebrities in this series, and regularly solves mysteries with them. This seems rather unlikely for the main timeline, so it's been grouped accordingly. Scooby also met the supernatural for the very first time in this particular timeline. In "Mystery in Persia," Scooby and the gang meets Jeannie, who is able to teleport them to Persia where they run into the evil djinn Jadall.
By networking with some of these above celebrities, Scooby got some media attention that allowed him to compete in various sporting events.
Mask of the Blue Falcon, WWE Films, KISS, Gourmet Ghost
The crossovers are included in with The New Scooby-Doo Movies for the same unlikelihood reason explained above. It's probable that Guess Who will be in this timeline when it's released, as well.
Behind the Scenes Interviews
The gang becomes famous enough to be interviewed about their adventures.
Night of the Living Doo
The gang meets several celebrities in this parody special while on their way to a spooky zombie-filled mansion.
#2: Scrappy's in the Picture!
The Richie Rich / Scooby-Doo Show
Branching off directly from where the main timeline left off, Shaggy, Scooby and Scrappy split off from the rest of the gang and begin traveling the world for a while (if you wanted to be imaginative, you could say to "find themselves" or some angsty teen concept like that). Fred decides to pursue his dream to be a mystery novelist and Velma applies for an internship at NASA during college (this is from "Happy Birthday, Scooby-Doo!" in The New Scooby-Doo Mysteries). Daphne goes off to pursue something else, maybe going to college to major in Communication/journalism, since she was a reporter in at least one episode of The New Scooby-Doo Mysteries. In this series, Scooby, Shaggy and Scrappy run into real monsters for the very first time.
The Scooby & Scrappy-Doo Puppy Hour
This series is pretty much the exact same dynamic as the previous one, except that Scrappy occasionally goes to visit his uncle Yabba out in the desert.
The New Scooby and Scrappy-Doo Show
Daphne rejoins Shaggy, Scooby and Scrappy while Fred and Velma remain busy with their careers. Daphne is still in college (possibly), and they continue encountering a mix of guys in masks and the supernatural. The career thing could be confirmed by the fact that in "The Crazy Carnival Caper," the gang comments that they've graduated high school.
The New Scooby-Doo Mysteries
Fred and Velma remain busy with career stuff, but occasionally come back to visit Daphne, Shaggy, Scooby and Scrappy. The gang continues to meet a mix of real and fake monsters.
The 13 Ghosts of Scooby-Doo
Fred and Velma become consumed in their careers again. Daphne, Shaggy, Scooby and Scrappy go on with their lives. Shaggy and Daphne may or may not be dating (purposely leaving that vague to avoid a ship war here, lol), but they travel together. They open a chest containing "13 of the most terrifying ghosts upon the face of the Earth" and have to recapture them all. I imagine Scooby-Doo and the Curse of the 13th Ghost will conclude this explanation for us! :)
Boo Brothers / Ghoul School / Reluctant Werewolf
Daphne begins focusing on her career again, while Shaggy, Scooby and Scrappy go off adventures meeting the supernatural by themselves. I suppose, begrudgingly, I could (sigh) put Arabian Nights in this timeline too, as Shaggy and Scooby being on their own is consistent with the rest of the gang's "splitting up" era.
#3: A New Hope?
A Pup Named Scooby-Doo
The gang is shown as kids and they solve mysteries in their detective agency. There are no real monsters in this timeline, or at least not known to the gang. Arguably, the Mystery Map film from 2013 could be lumped into this grouping as well. The reason for including Pup here is because of the flashback to Velma's birthday party in "A Terrifying Round with a Menacing Metallic Clown" (from What's New, Scooby-Doo?) where the gang is pictured together as kids, almost exactly how they look and act in Pup.
What's New, Scooby-Doo?
The gang is older now, and goes off solving mysteries meeting occasional celebrities. This is grouped separately from the "main" timeline only because of the unlikelihood of the gang meeting celebrities on a regular basis. However, this excludes "The Vampire Strikes Back," which is not in this timeline for reasons I'll explain later.
Loch Ness Monster - Samurai Sword
These movies go hand in hand with What's New, Scooby-Doo? There is indeed a real monster in Goblin King, though Velma, Fred and Daphne don't remember it due to the Goblin King's spell.
Abracadabra Doo - Big Top, Stage Fright, FrankenCreepy, Moon Monster Madness, Shaggy's Showdown and post-2012 specials
Though there's different animation, these assorted films still fit with this timeline and have the same general premise (even if it's a bit darker at times). The post 2012 direct-to-DVD specials also feature this same tone and plot type.
#4: Shags to Riches
Shaggy and Scooby-Doo Get A Clue!
I really debated putting this in the "fame and fortune" timeline with The New Scooby-Doo Movies, but I didn't want everyone to hate me! ;) In this series, Shaggy and Scooby split off from the gang after they inherit their uncle's fortune and have to try to rescue him from Dr. Phibes.
#5: Mystery Incorporated
Scooby-Doo! Mystery Incorporated
Pretty self-explanatory. The gang lives in Crystal Cove, and tries to solve the mystery of the Curse of Crystal Cove. It's sort of a combination of all the other timelines, besides #4 (Get A Clue). There are real monsters in this universe.
#6: Be Cool, Scooby-Doo!
Be Cool, Scooby-Doo!
This is pre-Where Are You, though it still fits with the main timeline. Shaggy has never seen snow before (until "Be Cold, Scooby-Doo!"), and Daphne is much more quirky. There are no real monsters in this universe.
Haunted Hollywood, Blowout Beach Bash and Knight Time Terror
LEGO films exist in their own timeline due to living beings and places being made entirely of bricks, and the fact that these beings have the ability to magically reconstruct these bricks with one's hands.
#8: Breaking the Fourth Wall
Scooby Goes Hollywood
Scooby Goes Hollywood exists in its own timeline because the characters are all just actors in a television show, which is comedically based on the franchise.
#9: A More Mature Era
Zombie Island - Cyber Chase
This timeline features more mature versions of the gang, where they decide to go their separate ways temporarily in Zombie Island before getting back together sometime between that film and Witch's Ghost. There are real ghosts and monsters in this timeline.
Legend of the Vampire and Monster of Mexico
This would have been part of the "main" timeline, but the gang already knows The Hex Girls in Legend of the Vampire, and there's no explanation as to why if its not in the same timeline as Witch's Ghost. It also seemed wrong to separate Monster of Mexico from Legend of the Vampire, so I moved this film into this timeline as well.
What's New, Scooby-Doo?: 3-D Struction and The Vampire Strikes Back
I had to separate these episodes out from the other WNSD episodes, since there's no explanation otherwise for how the gang would know The Hex Girls. 3-D Struction does not include The Hex Girls, but it includes J.J. Hakimoto who also appears in "The Vampire Strikes Back." Thus, these episodes needed to be taken out for the timeline to properly work.
#10: Live-Action Round 1
Scooby-Doo 1 & 2
I wanted to fit the live-action films into their own timeline as well, though they don't particularly fit neatly into any previously created one. Arguably, I'd say the first two films encompass the main timeline, as well as branch off from #1 (Fame and Fortune) and #3 (A New Hope?).
#11: Live Action Round 2
Scooby-Doo 3 & 4
The first two prequel films, Mystery Begins and Curse of the Lake Monster fit into their own timeline. This timeline has the gang meeting each other in detention at high school. In between the two films, there is an alternate reality version of "The Frickert Fracas" from the Fame and Fortune timeline, which doesn't include meeting Jonathan Winters.
#12: The Scooby-Doo Project
The Scooby-Doo Project
The gang gets lost in the woods and is killed. End of timeline. Haha
#13: Feminist Fun!
Daphne & Velma
Couldn't resist the title there lol. In this film, the girls meet for the first time online and go to Ridge Valley High together, where they solve their first mystery. After solving their first mystery, they receive a second mystery on their computer screen, when a mysterious voice tells them to stay away from the incriminating files they just found. Let's hope we someday find out how this timeline ends by means of a sequel! :D
Phew, I think I covered everything! Hope you all enjoyed reading my timeline. I would love to hear your thoughts on this, especially if you have a different way of grouping them that you think is more fitting! :)