Puzzle Swap

Puzzle Swap is a pre-installed game in StreetPass Mii Plaza.

Plot
In Puzzle Swap, the choosen Mii is a traveler that can can collect puzzle pieces either by passing by other 3DS users or by using Play Coins. For 2 Play Coins, the user can obtain a single puzzle piece, and although the piece is not guaranteed to be new, it is guaranteed to be from an incomplete panel.

There are several puzzles available in the game that focus on famous Nintendo characters such as Mario, Yoshi, Samus Aran, Link, Kirby, Pikmin, Donkey Kong, Fox McCloud, Chrom and Lucina from Fire Emblem, and Pit from Kid Icarus.

When Puzzle Swap is first started, a random starting puzzle piece is given to the user. The first puzzle varies for each user, and it is unclear how this puzzle is determined, though there are indications that it is determined by region. The only way to start a new puzzle after receiving your first piece is to pass by other 3DS owners who will send puzzle pieces from their puzzle boards.

During the December 2011 update, the number of pieces in some puzzles have increased. For example, the Rhythm Heaven Fever puzzle has 24 pieces instead of 15, like the original 7 puzzles. The Super Mario 3D Land puzzle has 40. Also, the pink pieces are different from normal pieces in that they can only be acquired through StreetPass. If a new user begins playing Puzzle Swap after the update including the pink puzzle pieces, they can receive a pink puzzle piece as their first piece and can they distribute it to others.

It is possible to restart Puzzle Swap to receive pink pieces as well;however, as this requires resetting the Puzzle Swap progress, this method would take a considerable amount of time (especially when factoring in the far more likely result of receiving a regular puzzle piece) and would require a second 3DS - one to generate the random pieces and one to collect all the pieces.

The number of pink pieces varies with the size of the puzzle from four in a 24 piece puzzle and up to eight for a 40 piece puzzle. A new update occurred late February, opening up several new puzzles. Only Kid Icarus: Uprising was the first puzzle to be revealed. On April 21, 2012, an update was pushed that opened a puzzle for Mario Tennis Open and Fire Emblem: Awakening, though only Mario Tennis Open was released internationally. As of the August 2012, several more puzzles have been released into the public to coincide with the release of other games (Kirby's 20th Aniversary, New Super Mario Bros. 2). In early August of 2012, a McDonald's Puzzle was given to 3DS owners who visited a McDonalds in Japan for a limited time. This marks the first instance of a non nintendo video game related puzzle. There was also a puzzle released in Japan called ANAでDS that was released at three airports in Japan.

On December 18, 2013, Satoru Iwata announced a new puzzle for Monster Hunter 4. This is the first third party game to be given a Puzzle Swap puzzle.

Play Coins
For two Play Coins, a player can receive a random blue puzzle piece of a panel that they have started. It is possible, and over time becomes increasingly likely, that the puzzle piece will be a duplicate of an already-collected piece, resulting in a null-gain. However, once a panel is complete, it is no longer able to receive a random piece to it, thereby increasing the odds of getting a new piece via Play Coins. Pink pieces and completed panels can therefore be considered "Locked," or "Fixed."

For example, a player with 400/1000 puzzle pieces may appear to have a %60 chance of getting a new piece. However, if those pieces included all available pink pieces, as well as completed panels, resulting in 200 "Locked" pieces, then the real odds would take those 200 out of consideration, resulting in a fraction of 200/800, or a %75 chance of getting a new piece. As such, it may benefit some players to first finish nearly-completed puzzles via StreetPass before putting in a siginificant investment of Play Coins.

Good news is that it doesn't seem possible to obtain a Blue Panel from a puzzle that has all its Blue Panels already. As such, if you are missing just a few Pink Panels from the puzzle, it is still not going to give you any redundant Blue Panels.Moreover, it could be worth your effort to specifically work on finishing puzzles (or at least their Blue Panels) before moving onto working on another puzzle.

List of puzzles
'The following are a list of confirmed puzzles in Puzzle Swap''. They are listed in the order they appear in the game.'''

 (*) Hover the mouse over the name to show the European title 

Trivia

 * Puzzle Swap is the only plaza game to not have an actual storyline