15 Puzzle

aka: Sliding Puzzle

Aw, crap.

The "fifteen puzzle" or "slide puzzle" is a sort of Stock Puzzle where one has to arrange a set of scrambled numbers so that they are all shown in ascending order. One spot is always open, allowing pieces to be moved around, but it is designed in such a way that no piece can ever be removed from the board. There are larger versions with more than than fifteen squares; these are called "n-puzzles", where n is the number of scrambled numbers (always a square number minus one).

A more general version of the "sliding puzzle" will have the player try to put together an image in the same manner as above. The picture you're trying to reassemble is usually printed on the back of the box to minimize frustration.

When used in video games, depending on the player's familiarity with this kind of puzzle, thay can easily become That One Puzzle or a source of Guide Dang It!; see here for a beginner's guide to solving them.

The puzzle traces back at least to Noyes Palmer Chapman in 1874; later on, Sam Loyd claimed to have invented it. Loyd did at least popularise the puzzle, by offering a huge prize each week in a newspaper advertisement for those who solved a certain configuration. He had analysed the puzzle and proved that half of all configurations are impossible to solve, naturally including the one in question, and thus nobody ever won the huge prize he offered.

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Examples:

Anime & Manga

• The titular Lupin III is able to solve them easily, as part of his safecracking abilities.
  • An n-square puzzle hides the Suminawa family safe in The Fuma Conspiracy. Lupin's remote control bug has to move cupboards around to the correct layout in order to see the safe.
  • A 15-block puzzle (incorporated into the wall) is part of the security that Lupin must get past to retrieve one of the statues in Lupin III: The Pursuit of Harimao's Treasure.

Literature

• Dream Park throws out one of these in a timed situation in The California Voodoo Game. The trick is that it's a word-version and there are two Rs: "RATE, YOUR, MIND, PAL". Put them in the wrong place and the puzzle is uncrackable.

Live-Action TV

• At least once per series in The Crystal Maze, usually a giant-sized version. The first two series featured a 5 x 5 version, which was never completed, except on one occasion in thirty seconds, by fluke. The third series had a variation in which the crystal was in the middle, and the goal was to get the middle square vacant, with four black pieces around it.
• CSI: NY: "Death House" features a large scale sliding puzzle as part of the floor in the apartment of an inventor. It is already solved and turns out to be part of a Death Trap.

Video Games

• Showed up as a hidden Mini-Game in Final Fantasy and all of its remakes. Accessing the puzzle required you to get onto the ship and hold down one button while mashing another. Completing the puzzle gave your party extra money, but just how much depended on which version of the game you played; in the NES version, it's a mere 400 gold, which can be earned much faster by simply fighting monsters.
• Also a mini-game in The Simpsons: Bart vs. the World, where pictures of the Simpsons cast were shown, and you would have to slide the puzzle around to make it look normal.
• Beyond the Beyond had a smaller sliding puzzle, which one had to complete to gain access to a church early in the game.
• Bloody Spell have optional sliding puzzles for you to unlock larger treasure chests, whereas smaller ones can be opened with the usual hacking at the lock. The sliding puzzle-related chests expectedly yields far better upgrades and bonuses than the common ones. Humorously, enemies within vicinity of these chests (including bosses) will patiently stop their attacks and patiently wait for you to finish your puzzle!
• Super Mario Bros.:
  • Super Mario 64: Such a puzzle appears in the Lethal Lava Land course. It solves and scrambles itself, though. Whenever it reaches the solution, coins pop out of all the panels. The puzzle is the only thing standing between Mario and hot molten lava, so the moving vacancy acts as a mobile hazard.
  • Mario Party: Island Tour: The minigame Tile Savvy has each character to slide the pieces of a scrambled puzzle in order to reveal an image, and doing so will reveal the next puzzle to solve. The first character to solve three tile puzzles wins.
• Some level 3 clues in RuneScape require the player to solve a 5x5 sliding puzzle to advance the quest.
  • A quest which has one of those is Monkey Madness. For extra difficulty, two of its pieces are nearly identical to each other. People were getting so desperate, they paid vast sums of ingame money to an NPC to not have to solve it! A Void Dance also has a 3x3 version.
  • There's also the infamous puzzle in Elemental Workshop III. A three-dimensional, multi-story sliding tile puzzle, which you have to work multiple times to complete, with an irritating interface, a limited amount of moves, and no way to fix even the smallest mistake.
• Appears in a library in a minigame in Xenosaga II. Particularly annoying as it's timed, but at least it's not required to advance the plot.
• In The Neverhood, the door to the Hall of Records opens only when you solve an 8-puzzle which depicts the letter 'H'.
• Another Code (known in the United States as Trace Memory) had such a sliding puzzle. Each time the puzzle was activated, the pieces would be ordered differently: Meaning that some combinations were trivial, and some were face-meltingly tough. Perhaps the only sticking point in the game if one is going for a new time record.
• The Legend of Zelda:
  • Appears as a minigame in The Legend of Zelda: The Wind Waker, where the result is the image of a character (there are sixteen images in total). However, Link is explicitly told by the sponsor (the Butler of the Private Oasis) that solving it gives no reward beyond money, and since money is much more easily obtained thanks to Treasure Charts, the mini-game serves little purpose aside from distraction should you like this kind of puzzle.
  • In the final dungeon of The Legend of Zelda: Skyward Sword, there's a variation. In several places, there are consoles with these puzzles, but each piece corresponds to a specific room, and you have to move them into varying positions to be able to traverse the dungeon.
• Resident Evil 4 has a 3×3 version during Ashley's playable segment. Once the picture is oriented properly, you have to use a key item to fill in the empty spaces to open the door.
• Machinarium has a 3x3 variant in which you must assemble an unbroken line from start to finish. This is also made slightly easier than most, both with markings to tell you where to put two particular pieces, and that another actually falling out gives you more space to work with. The missing piece gets eaten by a robot bird, though, and that's another task entirely to get it back.
• Professor Layton and the Curious Village has a version of this puzzle with an interesting twist: Two pieces whose positions cannot be swapped are identical.
• The PC game Secrets of da Vinci: The Forbidden Manuscript has one of these; after you've sketched a copy of the Mona Lisa, you have to slide the different parts of the drawing around until they are in the correct placement. In terms of the story, this is the most illogical puzzle in the entire game, as there is no plausible reason why you would have drawn it that way in the first place. (It's also one of the most difficult puzzles in the entire game, and many players have taken advantage of a glitch which forces the game to solve it for you.)
• Found in Barkley, Shut Up and Jam: Gaiden for a very cheap reward.
• Carmen Sandiego: Treasures of Knowledge has a 3x3 picture variation used on a locked door that has an artifact Carmen has stolen hidden behind it.
• Return to Zork has a puzzle that's close (a 3×4 "12" puzzle with the same basic mechanics). Trivially, solving it causes important items to suddenly appear where the puzzle was found. Guide Dang It! ensues when trying to figure out where each tile goes (it uses words as opposed to, say, numbers or a picture).
• The game for Finding Nemo completely overloaded on these.
• There's one in Castlevania: Dawn of Sorrow, but you don't really have to "solve" it; instead, each piece represents a room in a 16-square area, and arranging the pieces into a path allows you to traverse it. Each room can only be reached in one to three directions depending on the piece. Indeed, if you solve it "correctly", there will be four rooms you can't access; deliberately missolving the puzzle so that you can access those four rooms will net you some items.
• Heroine's Quest: In Svartelfheim a cavern complex is dictated by the layout of a boardgame in a residential inventor's home.
• Silent Hill adores these things. Silent Hill: Homecoming has a fiendishly difficult one with irregularly sized blocks.
• This is the premise of the minigame "Puzzle", which shipped with early versions of Apple Macintosh from the original to System 7. Later revisions of Mac OS replaced "Puzzle" with a jigsaw puzzle.
  Puzzle: [upon completion] Ta-da!
• Both The 7th Guest and The 11th Hour include this type of puzzle as rearranging the surface of a mirror to its previous state. However, since the missing tile is always randomized, it's possible for this puzzle to be set up in a way that leaves it unsolvable, forcing you to refresh it.
• One of the puzzles in AMBER: Journeys Beyond is this, here in the case of assembling a telegram that one of the ghosts tore up in shock of realizing her husband had died before returning from the war.
• Castle of Doctor Brain has one of these in the Maths hallway early in the game. Depending on the difficulty it will be 3×3 or 4×4 with numbers or 5×5 with an image.
• Safe Cracker:
  • One of the first safes in the Crabb house plays this straight. The strategy guide even gives you a cheat to have the game solve it for you. (Hold 'Alt' key whilst clicking on the handle).
  • In the 2005 Spiritual Successor, There is a variation which has no open space, but instead allows sets of four adjacent pieces to be rotated around their point of intersection. Also, the picture you need to reconstruct is shown only on the game's menu page.
• Sierra's Lighthouse: The Dark Being included a puzzle that plays this straight inside a cube with a puzzle inside each face. Dr. Jeremiah Krick managed to solve the first two puzzles before being unable to solve this. But the game is kind enough to give you a "Solve It?" button by backing out and zooming in 4 times.
• System Shock has an optional minigame that you can get as part of the "Trioptimum Fun Pack Entertainment Module", with pictures of Edward Diego, Abe Ghiron, and SHODAN that you must reassemble. It's not that hard, though, since you get to see the pieces scramble fairly slowly, allowing you to just do the process backwards.
• In Ripper, two cyberspace locations - the WebRunners' Archive and Falcon Eddie's personal well - are protected by these puzzles. However, the game has cheat codes for all the puzzles in cyberspace. A woman who gives you the former well's address unintentionally lampshades this.
  Woman: You're on your own with the ICE, though. It's a bench.
• Timelapse uses this as the last puzzle of the Mayan time zone, requiring four images found around the level to be assembled in the right order, and with the added difficulty of solving one of these images reducing the amount of space to move the remaining tiles.
• Certain Metalize tablets in Avalon Code reveal sliding puzzles that must be solved before you get the recipe.
• Forced upon you early on in Final Fight: Streetwise in order to progress and get some clues or something, then playable afterwards whenever you go back to the building and feel like playing it.
• The Sega Genesis version of Action 52 has this.
• In WarioWare: D.I.Y., Orbulon's boss stage is a 3x3 variant of this. The numbers shown by their respective tiles have to be arranged from 1 to 8 before time runs out.
• In the second game of Drakensang there's such a puzzle in the depths of the old Efferdian Temple on the Forgotten Island. You have to move the blocks in order to form the picture of a water nymph, but all the tiles are numbered. You also need the sixteenth tile from the Water Dragon's lair to complete the puzzle and reach the innermost chamber.
• The strange cube item in Kingdom of Loathing is a sliding puzzle with a twist. If you solve it the normal and obvious way you get a minor reward but if you solve it in another way hinted at nowhere in the game you get a better reward.
• Freddi Fish 2: The Case of the Haunted Schoolhouse has one of these on the ceiling above a statue, with three difficulty settings: one normal puzzle, one with a rectangular piece, and one with two rectangular pieces. Solving it is completely optional—the only requirement is to get the empty square directly above the trident the statue is holding, which you will then be able to remove.
• With the recent trend to mix Hidden Object Games with puzzle-solving, and the 15 Puzzle being a very obvious go-to puzzle, many casual games today feature this type of puzzle at least once per playthrough. The lower-quality games may be Unwinnable if the Random Number God is not suitably appeased beforehand.
• The flash game Continuity is exactly this puzzle combined with a Platform Game (ie. you can change the level by moving screens about in the style of sliding blocks).
• Viaje Al Centro De La Tierra begins with a puzzle of this type, fitting eleven pieces of a Treasure Map into their proper positions.
• The picture variant pops up in the SNES Thomas the Tank Engine game.
• Most levels in Black & White have one of these tucked away somewhere. Solving it yields some minor bonus, like a handful of some resource or temporarily freezing an enemy who normally attacks every few minutes, and it serves as a way to kill a few minutes while waiting for something else to get ready.
• One shows up in The Night of the Rabbit, though the player can't make Jeremy do any specific moves (clicking on the puzzle just has him cycle through positions, and the player can't even see the puzzle clearly). To solve the puzzle Jeremy must cast a spell on it, blowing it up.
• The interactive fiction title Not Just An Ordinary Ballerina slaps one of these on a door lock.
• Megapanel mixes this with the rising block stack-type Match-Three Game genre. By clearing the panels you limit how much you can move the others around, which forces you to rise the playing field.
• Exponential Idle: You can play the 15-puzzle minigame to earn stars, with its size depending on difficulty (3x3 on easy, 4x4 on medium, and 5x5 on hard).
• In both Lego Marvel Superheroes 2 and LEGO DC Super-Villains, some puzzles consist of 3x3 sliding puzzles. You get a large amount of studs if you complete it flawlessly.
  • In general this is a common type of puzzle in Lego Adaptation Games.
• Zombie Claus: There's a slider puzzle on the wall in one of the bedrooms. It needs to be solved to open a closet door with a present behind it.
• Progressbar 95: Progressbar Largehorn and Wista have a small playable 3x3 puzzle where you move tiles to an empty tile around to form a picture or put standard numbers in order. It's optional, but gives extra points once the level is completed.
• Dragon Age: Origins Downloadable Content, The Stone Prisoner, has a variation in which to solve it, the player must render a path for a stream of flames to follow and hit a magic pedestal.
• Dangerous Adventure II uses 15-puzzles for its lockpicking mechanic (letting you open chests without a key), using an image of a chest instead of numbers. Failing makes you unable to open the chest until you restart the map (which also respawns the enemies).
• Later Alligator: This is Papouli's minigame. It starts out with a 3x3 version in order to reassemble a picture of his late wife, but after that's done, he sneezes, revealing a standard 4x4 puzzle on the other side, with a picture of his secret other wife who is currently in witness protection. The game has an auto-solve feature for this puzzle if the player takes too long, but a puzzle piece is awarded for solving these puzzles without it.
• Wild Blood have these puzzle types, sandwiched in-between killing legions and legions of Morgana's minions, where their completion is compulsory to obtain keys accessing the next stage. One walkthrough on YouTube even lampshades it in the description: "I HATE SLIDING PUZZLES!"
• Ghost Trick: In the iOS version and the HD remaster, there are three sets of three 15-puzzle games, one each being 3X3, 4X4, and 5X5. In the case of the latter re-release, completing all three 5X5 puzzles can net you the "Shifting Shape to Get By" achievement.

Real Life

• They were included in Windows Vista and 7 as desktop gadgets.
• Sam Loyd, who claimed (probably falsely) to have invented the puzzle in the 19th century, offered a $1,000 reward. The puzzle conserves parity and cannot be solved if the numbers 14 and 15 are swapped, which was the configuration he provided it in. Rumor has it that Loyd couldn't patent the puzzle because it was insoluble, though "because he didn't invent it" is another plausible reason. Perplex City has a card based on Loyd's version of the puzzle. Henry Segerman demonstrates a variation of this impossible puzzle where the puzzle is projected onto a cylinder and the opposite corners are placed adjacent to each other. This enables one to change the parity of tiles, thus rendering the problem soluble.

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