Magical Mystery Doors

A recurring Stock Video Game Puzzle of the eight-bit NES era, it is the Platform Game equivalent of The Maze. The player will be placed in a small room littered with doors. Entering a door will lead him to another room packed with doors, or a dead end, or the start of the stage, or a small moon orbiting Jupiter. Generally, only one door in a far-away, hard to reach room will be the "correct" door that leads the player out of the maze. Be sure to keep your eyes open for little pickups to find for Hundred Percent Completion in case several of those are lying somewhere in a dead end.

See also Door Roulette. Super Trope of One of These Doors Is Not Like the Other (the variant where the correct path is hinted at).

The Beatles song, album and film Magical Mystery Tour is the Trope Namer.

Action Adventure Games

 * The Goonies II was all about this. Two side-scrolling maps were connected entirely by a massive labyrinth of mystery doors... which was presented in first-person.
 * In The Legend of Zelda Links Awakening, you must go through Magical Mystery Corridors in the Wind Fish's Egg to get to the final boss. Fortunately, you can find a book in the library that tells you the exact order in which you must take each path to reach it.

Action Games

 * Monster Party has a set of Magical Mystery Doors about two-thirds of the way through the game. While you're struggling to determine which door will end the pain, you'll be fighting animated pairs of pants with a baseball bat. Yes, it's that kind of game.
 * Very definitely Rambo for the NES. Each area in the game is connected by small pads marked "S" and "N", but it's anyone's guess as to where they will actually take you.
 * Super Shinobi (aka Revenge Of Shinobi).
 * Astyanax. The second-to-last level, Thelenea Castle. The trick to getting out of this one is looking for the doors with the skeletons in front of them.

Action RPG

 * Marvel Ultimate Alliance has one with a unique twist. At one point, Dr. Doom (now with A God Am I powers) creates a system like this, where entering one door would spit you out of another one instantly ala Scooby Dooby Doors, with Doom's laughter mocking the player every time this happens. So how do you beat it:

Adventure Games

 * In the interactive fiction game Adventure, there are two mazes, one where all you see is "twisty passages all alike" and one where all you see is "twisty passages all different". Or, if you're paying attention, you might notice
 * Secret of Monkey Island 2: LeChuck's Revenge has one of these near the end. You have a hint, though, in the form of a cryptic song you've got written down.
 * The Perils of Akumos offers the agonizing sandstone caverns. The official guide urges players to draw their own map, which eases matters from "impossible" to merely "difficult."

Beat 'Em Up

 * Renegade has Magical Mystery Doors in the very last stage. Pick the wrong door and you're taken back to the beginning of the stage. Pick the right door and a thug with a machine gun jumps out of nowhere and kills you with a single hit, taking you back to the beginning of the game.

Eastern RPG

 * Final Fantasy I and its aptly-named Castle of Ordeals.
 * Nearly every Pokémon game, including some of the spinoffs, have a Magical Mystery Teleport Tiles section somewhere, usually in the bad guy's hideout.
 * Most egregiously in the Psychic Gym in Red/Green/Blue/Yellow (and later repeated in FireRed/LeafGreen), where there are nine rooms, the entrance and the leader have one teleporter each, and the rest have four, each going to a separate room. Oh, and all those other rooms? each has a Jr. Trainer. Strangely, you can brute-force the tiles by just going to the one on the same side as you, avoiding the line-of-sight of each trainer, getting to Sabrina easily.
 * There are also Magical Mystery Doors on every end of each room in Turnback Cave on Diamond/Pearl/Platinum. And they're randomized each time you go through the cave. However, there are occasionally pillars that appear in a new room to tell you you're going the right way.
 * The first Star Ocean 1 features a set of fast-moving slimes. Some will trigger battles, some will warp you further on, and some will punt you back to the beginning. Luckily each "puzzle" only spans a single room, but it can get frustrating.
 * A small section in one of the two added dungeons in the DS remake of Chrono Trigger has another teleport section where you need to guess which one leads further.
 * Final Fantasy XII has the Great Crystal. It is one of the few areas in the game without a map and contains some of the most useful items in the game. It's also compulsory. There is one way out, and one save point. And attempting to make a map on one's own will likely end in tears, for the area names are a code in goddamn Sanskrit. And it has gates that block the way unless the player turns off corresponding mechanisms, usually in a far off room. And then the gates will close back up anyways if the player doesn't get to the gate in time. Is anyone surprised that this is possibly the most reviled level in the game?
 * Earthbound's desert monkey maze, with monkeys blocking hallways demanding various foods and trinkets before they will move out of the way, just so you can get to another room with more monkeys demanding more trinkets that are located in a hallway guarded by some other monkey.
 * Megaman Battle Network 4 and 5 each have one of these. In each case, you jack into an object that isn't connected to the Net and doesn't have its own unique network, just a seemingly endless series of featureless maps with warps leading to other featureless maps with warps leading to you get the idea.

Miscellaneous Games

 * Hotel Mario had a lot of these.
 * The online pet/game site Neopets once included a Magical Mystery Doors puzzle as part of a plot (a periodic site event). The building containing the doors was known as the Temple of 1,000 Tombs. A detailed explanation of the puzzle and the entire plot is still available here.
 * Ah, Yume Nikki and its Magical Mystery Warp Tiles.
 * Subverted in that there is no "right way out"; getting lost in the maze of doors is itself the objective.
 * This appears in Glider 4.0 and Glider PRO as Magical Mystery Ducts. In Glider 4.0, Room 40 of "The House" had four ducts, three leading to previous rooms and only one leading to the second part of the house.

Platform Game

 * In 8 Eyes, for the NES, half the stages are designed like this, turning the game into a sadistic Möbius Strip where you run past the same scenery over and over until you resort to a handy issue of Nintendo Power.
 * Several times in the Kirby series.
 * Kirby Super Star: the planet Skyhigh in "Milky Way Wishes"
 * Super Mario Bros. resorts to this on occasion:
 * The final stage of the original Super Mario Bros. has pipes that operate this way: Each area has several pipes, one of which will take you onward, and the rest of which will take you back to the beginning of the level. There's actually a subtle clue there, though...
 * In Super Mario Bros. 3, the first fortress of World 3 has several doors that drop you into water, leaving you to swim back to the only door you can reach from here, which returns you to the beginning of the area.
 * Several of the Ghost Houses in Super Mario World, especially the last one.
 * New Super Mario Bros. (Nintendo DS). Hey, it's a game with Magical Mystery Doors that wasn't released for the NES! There's a section of the game where you're perplexed by a series of doors. The only way to discover where they lead is to test each and every one of them. Fortunately, it's much shorter than most Magical Mystery Doors segments tend to be in NES games.
 * A minigame in one of the Mario Party games (I think it was 4) had this with the pipes, too.
 * Super Paper Mario has this in the second world. Oh, and there's the added bonus of a literal Demonic Spider with Nigh Invulnerability that comes to kill you if you stay in one room too long. Often the rooms are hard to navigate.
 * The first two games in the series also had this in the final dungeon. Both times there were two floors, and on both sides of each room, there was one door on each floor, making three doors to choose from when you ignore the door you just came out of. The solution was the same in both games:
 * The penultimate stage "Simba's Return" of The Lion King game.
 * Any teleporter in Kid Chameleon can send you... somewhere. More frequently "Elsewhere" (the name of a great deal of mini-levels), sometimes backwards, sometimes necessary to advance.
 * The first of the new Prince of Persia games has two rooms pretty much made of doors, which if you didn't go through the right two just sent you around in circles. The only clue to the correct doors was the sound of water splashing as you walked by them.
 * Indiana Jones Greatest Adventures plays this trope with statues rather than doors...But then, nearly every level in that game is an extremely annoying gimmick level.
 * Sonic 2006 offers a slightly watered-down, but no less annoying, variation of Magical Mystery Doors on the way to the old Soleanna palace using portals.
 * In Sonic Adventure, in Amy's version of Final Egg, there's a room with five doors. A random one of these doors leads to the last part of the stage; the others lead to dead ends with blue hovering robots. In Sonic Adventure DX, one mission in Mission Mode requires you to hit a button, then find a flag within a few seconds. The flag is hidden in a random one of the dead ends, and if you go down the path that takes you to the next part of the stage, you have to start the stage over in order to complete the mission, or just the section if you didn't hit the checkpoint.
 * The final level of Commander Keen: Aliens Ate My Babysitter contains one of these. You appear to enter the same room with four doors twice, then back out where you started.
 * The final planet in The Adventures Of Rad Gravity has a magical mystery teleporter maze, which can by mostly bypassed via teleport glitching.
 * Level 15 of the SNES adaptation of Prince of Persia has these.
 * Toejam and Earl: Panic on Funkotron included an area with mystery doors as part of level 15 (The Bottomless Pit). Most doors take you to a variant of the same area, distinguishable by different plants and different characters that appear. Only one door in one of these variants leads out of the maze.
 * The coffin maze in the penultimate level of Bart vs. the World for the NES.
 * The final level in Tempo for the 32X used this. Oddly, the player had to skip the first two areas through easily noticeable elevators and then go explore a maze of doors. At the end, the player is presented with 4 doors. The game tries to trick the player into entering the second, but the right door is the fourth.
 * Stage 12 of Vampire Killer has a maze of doors connecting a bunch of corridors, most of which wrap around. (The corresponding stage in Castlevania 1986 for the NES is straightforward and practically a Boss Only Level.)
 * The Famicom game Atlantis no Nazo is one long and frustrating exercise in this trope, including hidden doors and doors that can only be reached by blowing yourself up.

Survival Horror

 * Silent Hill Shattered Memories has one towards the end. It's not that difficult when you realize you just have to go into the doors surrounded by icicles... but try to figure that out on the move, while you're being chased by enemies and running like hell.

Non-video Game Examples

 * A rare literature example appears in the fifth Harry Potter book. It's the antechamber of the Department of Mysteries.
 * Film example: Yellow Submarine has some Magical Mystery Doors. This is determined when hunting for George and Paul. It takes multiple tries and a close call with a train to find the door Paul is behind...