Pokémon Diamond and Pearl

Pokémon Diamond and Pearl were the first Pokemon games in the 4th generation.

Demo Version
The kiosk demo of Pokémon Diamond and Pearl was used in stores prior to the game's release, and contains many differences from the final.

Unused Items
Quite a few Key Items remain in the code. If hacked into your inventory, they have no use, but they all have item descriptions.

Azure Flute


"A flute that puts out echoing sounds that do not seem to be of this world. It is unknown who made it."

See its own section.

Contest Pass


"The pass required for entering Pokémon Contests. It has a drawing of an award ribbon on it."

This was required in Ruby and Sapphire to enter contests, but not in Emerald. Apparently scrapped in this game, too.

Loot Sack


"A sturdy, spacious bag that is used to carry loot obtained in the coal mine."

Would have been used to carry the items found in the underground. In the final game, the underground menu serves this purpose.

Magma Stone


"A stone formed when boulders melted in intensely hot magma, then hardened. Magma remains sealed inside."

This item figures into the Stark Mountain events, but is only handled by NPCs. Like all of Generation IV's key items, this hangs around forever and ever in newer games... ...until it's finally obtainable in Pokémon Black 2 and White 2.

Red Chain


"A mythical chain that is said to link the legendary Pokémon that created the Sinnoh region."

Cyrus uses this as a part of his ultimate scheme, but the player never gets ahold of it.

Rule Book


"It lists the rules for holding battles. For linked battles, you may choose which set of rules you wish to use."

Was possibly required at one point to select different battle types in link battles.

Seal Bag


"A tiny bag that can hold ten Seals for decorating Poké Balls."

Apparently dumped in favor of the Seal Case.

S.S. Ticket


"The ticket required for sailing on the ferry S.S. Anne. It has a drawing of a ship on it."

Every game before this had an S.S. Ticket for some sort of boat.

Early Great Marsh ()
A Great Marsh without wild Pokémon, people, or any events. The game names this area "Pastoria City", and the Mystery Zone music plays (SEQ_DUMMY).

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Jubilife Condominiums 3rd and 4th floors
Jubilife Condominiums has 2 extra floors. One of them has Gym music and a Focus Band given to you by an NPC.

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Unused Sunyshore house
Sunyshore City has an unused map with two NPCs who cannot be interacted with by the player. It appears to have undefined map coordinates regarding its exit point. 6EGD6cBUx1k

Oreburgh area
One of the five unused areas in Oreburgh City. This one has two guys, with normal dialogue string. dp5CPH_OnWs

Unused Music
In the games, there are a few samples of unused music.

Ruby/Sapphire/Emerald Title Theme
MIDI HEX is the title screen music from Pokemon Ruby/Sapphire/Emerald. This was likely used for testing purposes when the game was being developed.

Gym Leader Battle Theme
Either MIDI HEX or  is an unused remix of the Gym Leader battle theme, which was supposed to be used for the Palmer battle in the Battle Tower, before being replaced by Cynthia's theme.

Early Route 206 / Mystery Zone
There is also the Mystery Zone music, which is a very early version of the Route 206 theme. It is MIDI HEX.

Early Route 205
Two early versions of the Route 205 tunes. Interestingly, the unused Night music is a bit faster than the unused Day music.

Early Jubilife City
An early version of the Jubilfe City music. The bell instrument is missing.

Early Eterna City
An early version of the Eterna City Day music. The pipe sounds different.

Early Lake Crater
An early version of the Lake Crater music. Some instruments are missing.

Hall of Origin and Azure Flute
An event item exists known as the Azure Flute, which was never distributed. When hacked into your Bag, the Azure Flute can be used at Spear Pillar to warp to another map, the otherwise unused Hall of Origin above Spear Pillar. Atop a glass staircase, on a platform high in the sky, you encounter a level 80 Arceus. It seems this event was the originally planned method of Arceus distribution, but for reasons unknown Arceus was distributed directly as an event Pokémon instead.

Interestingly, it seems that an Azure Flute distribution wasn't ruled out as late as the releases of Pokémon HeartGold and SoulSilver; those games have a mechanism to allow a Hall of Origin-caught Arceus to return the player to the Sinjoh Ruins and get another one of the trio of Dialga/Palkia/Giratina.

Shiny Arceus


For the sake of consistency, every Pokémon in every Pokémon game is given a Shiny variant. Arceus is no exception, having a Shiny palette for each of its 18 forms, including the one not accessible through normal gameplay (see below). However, because the only way to obtain it legitimately was through distributions, the Shiny version of Arceus was left unobtainable through normal means.

Unused Arceus Form
Arceus has an unused form as well! Arceus' type changes to the type of the plate it is holding. However, it also has a ??? form, based on the special ???-type most notably used as the type of the move Curse (up until Generation V). Because there is no plate based on this near-placeholder type, this form is never seen.

Unused Models
In the games, there is also an unused model that is used for shops. It is very similar to the ones placed outside shops in Pokémon HeartGold and SoulSilver, but is independent of the shop model, and they also don't rotate. Through hacking, these models can be loaded to the game and work perfectly fine, except they don't glow, unlike the Pokémon Mart.

Unused Accessories
One unobtainable accessory and one unobtainable backdrop exist in the game. It is unknown how either of them would have been obtained, though the Comet can be obtained through Pokésav.

Unused Texture Set
Within the game's texture files, there is a set of textures that go unused, and ultimately display unused graphics. However, these textures were displayed in some pre-release screenshots of the game, so it was likely that these textures were placeholders and were intended to be removed. The textures can be displayed in-game by reloading the graphics while in the Mystery Zone and then returning to the overworld. Interestingly, the dirt path tiles seem to have been shifted around in development, and the water tiles appear to animate incorrectly. The textures are identified as texture 0 within the game's coding.

Route 217 Snow Texture Set
In the textures that are used on Route 217 (Identified at texture 14 in the game's coding), there are a few unused textures. One of which has seems to be a placeholder for the bicycle stands that appear in Eterna City and Oreburgh City.

In that same set of textures, there is also unused textures for the lakes and their respective edges. However, only the center of the lake has textures, the edges do not appear to have any textures in the designated texture file. They may have been removed during development, or they may have made the main lake texture, but never finished the rest of the still lake texture in favor of moving water for Lake Acuity, which uses the same texture set.

As well, in the Snow Route Textures, also appears an unused path texture, a differently-colored version of the loamy soil for berries, and a slightly brighter edge around the puddles. The loamy soil texture would have gone unused mostly due to the fact that no berries would have grown in the locations where it's texture would have been used, but was never removed. They may have also been copy/pasted around during development to save time, and were never removed.

Unused Trainer Sprites
In the game's files, there are three alternate Trainer battle sprites, as well as a sprite meant for an unused Double Battle combination of a Swimmer (male) and Tuber (girl), called "Sis and Bro".

Ketsuban
A placeholder sprite, which reads "Ketsuban", or "missing number".

Unused NPC
A generic male NPC, which is never used in the game.

Unused Large NPC
A different version of the larger NPC's sprite. The unused version looks more stretched-out, making the sprite seem...even larger.

Unused Rival Sprites
Sprites of the Rival either swimming or Surfing on a Pokémon.

Surf glitch
In the Japanese version of Pokémon Diamond and Pearl, it is possible to surf right through the entrance door in Aaron's room in the Pokémon League. This makes it possible to traverse the entire void, which can lead to useful things (such as capturing the normally event-only Pokémon Darkrai and Shaymin without needing any event), but can also result in the player being stuck forever, especially when saving. This has been fixed in the international versions of the game.

Item cloning
In the Japanese version, if a Pokémon holding an item uses the move Transform and then has its item stolen in battle, both Pokémon will retain the item after battle provided the transformed Pokémon does not faint. This can be used in double battles to easily duplicate items. This bug too was fixed in the international releases.

Mimic glitch
Another glitch exclusive to the Japanese version of the game, if a Pokémon uses Transform by way of the move Mimic and then faints after transforming, it will keep the moveset of the Pokémon it transformed into forever.

Registeel Sprite
In the non-English European versions of Diamond and Pearl, Registeel's sprite was edited because of its arm. The arm's original position is reminiscent of the salute of the Nazis. The sprite change was later applied to all versions of Pokemon Platinum and retained for HeartGold and SoulSilver.

Ability bugs

 * The Attack and Speed drop provided by the Slow Start ability is retained in the Japanese version even if the ability is removed, for example by way of Skill Swap. This was fixed in the international versions.

Rotom, Giratina, and Shaymin Alternate Forme Placeholder Data
There exists placeholder data for alternate forms of Rotom, Giratina, and Shaymin in Diamond in Pearl, suggesting the alternate forms (sometimes referred to as "Formes") featured in Pokémon Platinum were already in development. There is a table within the game's coding that specifies the number of Formes/forms a Pokémon has. Pokémon that have no alternate forms are listed with the number 0. Pokémon with alternate forms are listed with a number corresponding to the number of forms they have. For example, Pikachu has the number 0, while Deoxys has the number 4. There are three exceptions to this: Rotom, Giratina, and Shaymin are the only Pokémon listed with the number 1. It seems this number is meant to be a placeholder, meaning that at least one alternate Forme is in development.