Sonic the Hedgehog:
The first game. Enough said. Included in Sonic Origins.
Sonic the Hedgehog CD:
Released between 2 and 3, but starting production after 1, it has been a heated debate for years whether it happens before Sonic 2 or after Sonic 3 & Knuckles, given that the ending of Sonic 2 leads directly into the beginning of Sonic 3, so the game cannot happen in its release order. But all those years of debate ended when Sonic Origins confirmed that yes, it does happen between 1 and 2. Included in Sonic Origins.
Sonic the Hedgehog 2:
Sequel to Sonic The Hedgehog, where Tails makes his debut. The manual describes how Tails met Sonic, but thankfully, the Sonic Origins intro cinematic for the game recreates the scene in animated format. Included in Sonic Origins.
More on this in the Modern Era.
Sonic the Hedgehog 3 & Knuckles:
Composed of 2 games: Sonic The Hedgehog 3 and Sonic & Knuckles, they have a special technology where one cartridge can fit into the other and therefore you can play the games separately or connected, with cinematics connecting the two games. Standalone 3's final cinematic makes it impossible for the & Knuckles plot to happen, so the canon version is the connected version. Included in Sonic Origins.
More on this in the Modern Era.
More on this in the Modern Era.
Sonic Mania Adventures:
More on this in the Modern Era.
Sonic the Hedgehog 4: Episode I:
Released well into the modern era, this game is supposed to be a modern-classic Sonic game. It is generally considered along with the other 2 episodes to be one of the worst Sonic games. Since the characters are in their modern style but the game has to be one of the early modern era games, if not the first, or at least it has to predate Sonic Heroes, I am placing it at the beginning of the modern era.
Sonic the Hedgehog 4: Episode Metal:
DLC or something of Episode II, it is obtained buying Episode I and Episode II in the same platform. You play as Metal Sonic in the levels of Episode I but with the engine of Episode II. Happens at the same time as Episode I. The intro cinematic ties into Sonic CD.
Sonic the Hedgehog 4: Episode II:
Obviously this is a sequel of Episode I. It is also a sequel to Sonic CD, because of Metal Sonic, and Sonic 3 & Knuckles because this Death Egg is the Mark II, the original being the one in Sonic 3 (Tought I think one of the old games, I think was Sonic the Fighters already had a Death Egg II).
Could be in any place in the modern era, but I asume that happens before Advance 2 because of the title.
Sonic Advance 2:
Cream is introduced here and since she makes a cameo in Sonic Adventure (only in the DX version that was released after this game) I put this game before Adventure. Still by the way the cameo is presented, it could be considered non-canon or not impliying she has already meet the main cast, so, this game could be in any place of the modern era after Sonic Advance and before Sonic Heroes.
Sonic Adventure / Sonic Adventure DX:
First game by release in the Moden Era. Sonic Adventure DX is a rerelease of the Dreamcast game in the Gamecube. Aparently the Game cube was inferior to the Dreamcast in graphiscs and capabilities or something like that, so, the fact that every re-release of the game is based in the Gamecube version makes some people upset. I don't know, man, I am too young for this old console war so, to me all graphics look like 2000s era graphics, so I don't really care Plus on pc there are mods to restaure the Dreamcast enchanments so, at this point it is a ponintless debate, just choose whatever textures you want.
Apparently this game is like a Mario Party but with Sonic characters. I don't knw too much about it, since is not in modern consoles. Aparently the character are transported to a parallel dimension made out of the dreams of the real world inhabitants or something. Has like cameos of NiGHTS into Dreams characters that make people theorize that they happen in the same universe, but since NiGHTS inti Dreams characters cameo rather frecuently and gratuitously in Sonic games without context, like in the pinball machine of Sonic Adventure casino level, I am not trusting theories until I found more evidence.
Sonic Adventure 2 / Sonic Adventure 2: Battle:
Sequel to Sonic Adventure. Nothing special about its placement.
Sequel of Sonic Adventure 2. Thats it.
Shadow the Hedgehog:
Continues the Shadow plot of Sonic Heroes.
Aparently Shadow has his memories back in this game, when he had to regain them in Shadow the Hedgehog, so, the 2 games hapen in the oposite order they where released.
Sonic Advance 3:
The game is a sequel to Sonic Battle. Could be in any point after Battle, even after Generations or Lost World, but given release dates, and that Sonic Rush is something of a Sonic Advance 4, and that if the Sonic IDW comics are taken into acount, it has to be before Sonic Forces, I am placing it here.
Sonic the Hedgehog (2006):
It's called "Sonic The Hedgehog" just like the first game. Hence the 2006 to differentiate them, which is why most people call it Sonic '06. It seems that the idea was to make a Sonic Adventure 3 but apparently it failed miserably. I personally think the bugs are the worst part, the plot is nonsense, but no more nonsense than other games in the timeline. It features time travel, but has the typical plot hole in time travel stories that introduces conflicting time travel rules. Shadow's story states that time runs in a loop, while Silver's story states that the timeline can be changed. Sonic's history is a bit ambiguous. The final story also follows Silver's story rules of time travel as the characters travel 10 years into the past and seemingly erase all the game events from history, well, except the last scene, in the new timeline. The characters apparently don't remember anything from the previous timeline, and the rest of the games seem to have happened the same way, so it's not worth creating a new timeline in the thread.
Released before Sonic '06 but given the revelations of that game, I am placing it here. I don't have an explanation of the time travel-dimension hopping timeline of Blaze and Eggman Nega, maybe I add something later, but I think that Sonic '06, Rush, Rush Adventure, Rivals and Rivals 2 work better the way they are placed here. This game introduces Blaze (unless you count Sonic '06) that is inhabitant of another dimension.
Sonic Rush Adventure:
Sequel of Sonic Rush Adventure, this game happens mostly in Blaze's Dimension
This game reintroduces Silver after Sonic '06. The rivals games were released interwoven with the Rush games but seem to change their mind wether Eggman Nega is Eggman's descendant from the future or a alternate Eggman fromanother dimension. Maybe there are 2 Eggman Negas. I put this here asuming that they are the same and in the Rush games he lies knowing that he is a Eggman's descendant and since he is friends with Eggman in the Rush series but an enemy in the Rivals series, he and Eggman had an argument at the end of Rush Adventure and turned enemies.
Sonic Rivals 2:
Sequel to Sonic Rivals.
Sonic Chronicles: The Dark Brotherhood:
There was an army of evil echidnas in the Archie Comics who were enemies of the tribe Knuckles belongs to. One day Archie or Sega fired the comic book writer. I don't know if this was after or before the Sonic Chronicles game was produced, but the villains in the game are clearly an adaptation of the evil echidnas from the comic. After the writer left, the judge ruled that Sega or Archie can't use the characters he made for the comic without his approval. Apparently, fearing a lawsuit, Sega hasn't released a Sonic Chronicles sequel because, while they technically can, they can't use the villains that are clearly pastiches of Archie Comics villains. So the game might be canon, but you can't reference it, which is, technically, the point of continuity. If the game is canon, it continues the plot of Sonic Battle.
One of the best Sonic games. Placed here by release date.
Sonic and the Secret Rings:
Sonic travels to the arabian nights world and fights an evil genie. Sonic Generations references it in one line of dialogue, so, aparently canon.
Sonic and the Black Night:
Similar to the above one but with arturian legend instead of arabian nights. Since the previous one is canon, this probably is too.
Sonic Colours / Sonic Colours Ultimate / Sonic Colours (DS):
Another beloved Sonic game. Ultimate is the remaster for the current gen. Colours for the DS has multiple cameos of characters of previous games, with seems more interesting that the mainline version, that only has like 7 named characters, but aparently the console version is the canon one, tough it has exclusive Wisps that apear in later games. The portable version gameplay is like Sonic Rush, made by the same develoers so it is like Sonic Rush 3 and given my previous coment about Sonic Rush being like Sonic Advance 4, this game is like a Sonic Advance 6
Another good main Sonic game. Wow, 3 in a row. The plot is a little nonsensical, all things considered, but it establises that most of the previous games are in continuity. More on Classic Sonic later.
Sonic Lost World:
The next Sonic game.
Sonic Forces digital comic:
A 4 issues free digital comic made to promote Sonic Forces.
More on this later
Sonic the Hedgehog (IDW):
The actual series of comics about Sonic. It is supossed to be canon, but the wiki lists its characters as separate continuities, but I can not find any evidence of the comicbook contradicting the games, so, maybe it is a preventive measure in case the comic and videogame continuities diverge. Probably has some short of timeskip once Sonic Frontiers is reached, but I haven't readed too many of the issues, so, I would expand once I have read.
I have not played yet, will add information once I do.
I have not watched yet, will add information once I do
Notes on Classic Sonic/Sonic Generations/Sonic Forces/Sonic Mania/Sonic Mania Adventures:
Classic games had Sonic, a 15 years old hedgehog as a main character. Sonic Adventure redisigned the main cast so they look older and cooler. It was never explained if they grew up or if they just changed artstyles. Sonic Generations made it so that the classic design is the past Sonic and the modern design is the present Sonic, so, the iplications seems to be that he has grown up in-universe from his classic design to his modern dessign. At the end of the game Classic Sonic and Tails go back to the past. Then Sonic Mania was released and starting the Mania-Forces dilema: Sonic Mania happens after Sonic and Knuckles, since Knuckles also appears and he is aware of Eggman being evil. We are lead to either belive that this game is the new divergent timeline where Eggman tries diferent plans knowing that any of his plans didn't work in the future, or that this events also happened in the past of the "original timeline". But then the true ending kicks in and it ends with the Phantom Ruby and the Emeralds opening a portal that sucks Sonic and the Ruby. The same Ruby that apears in Sonic Forces. Acording to the prequel comic, literally the Ruby lands in Eggman door. Aparently Classic Sonic lands 6 months later, for some reason. When Classic Sonic appears both Eggman and Tails refer to him as a "Sonic from another dimension", together with the fact that Sonic sees Classic Sonic trought a cristal in Sonic Generations and both seem to confuse the other Sonic with their reflections, made people think that the 2 Sonics look the same in-universe and that the diferent artstyles are just there for the benefit of the audience. The general consensus seems to be that after Generations the timeline split because of the knowledge that Sonic, Tails and Eggman adquire of the future and that Classic Sonic Universe used to be Modern Sonic Universe past, but is currently a split timeline. However, in a recent interview the writter of the IDW comics and current games and ex-writter of the Archie Sonic comics (not the one that they fired and ended in bad terms with SEGA, that was the previous one) said that according to SEGA the worlds of Classic Sonic and Modern Sonic are the same once again, tough for marketing pourpouses the characters are going to be divided in "Classic" and "Modern" eras, so he is not alowed to use Modern characters in Classic games and viceversa. Taking that information into acount, then the Sonic Timeline is a loop, meaning that characters experience the events and their time travel leads to the events that lead to the time travel (english is not my first language, I know that the last sentence didn't make any sense, but I am not even capable of saying that in my language, the people that know about time travel know what tipe of time travel I am taking about). If you have the question of why Modern characters don't know about the plot of Generations if they already experienced it before, I don't know, the Post-Super Genesis Wave timeline in the Archie Comic Universe had a Sonic CD adaptation where Sonic comes back from Generations to the plot of Sonic CD and starts to forget his adventure in Generations, so, even if it is a different universe (and posibly multiverse too) we can extrapolate the explanation here. That raises the question of why he remembers Generations in Forces, so, maybe the universe lets he remember time travelling memories when he is in another time period or he holds on the memories from the entirety of 3 & Knuckles, Mania and Forces and later he forgets. I put Generations from the Classic point of view between 2 and 3 because he seems to remember Tails but I am probably going to change the placement. The Encore Mode of Sonic Mania Plus and the free animated series Sonic Mania Plus (on youtube and Sonic Origins gallery) offer contradictory explanations of how Sonic returned from Forces universe. I put Mania Adventures because I think is more entertaining to watch that to play Encore Mode that is just another version of regular mode without too many additions. That stills leaves the question of why Tails and Eggman refered to Classic Sonic as Sonic from another dimension, but whatever.