Java Edition removed features

Since the beginning of the development of Minecraft: Java Edition, there have been a number of features that were removed from the game. These features may have been replaced, or a developer decided against the feature later on.

Note that this page only documents game features that were removed; features of a particular game element that were removed are noted in that element's history. See Java Edition unused features for features that are still currently in the game.

Horse saddle


Horse Saddles were items that were added in snapshot 13w16a during the development of 1.6.1, along with horses. Horse Saddles worked just like regular saddles, but for horses instead of pigs. Taming a horse was required before putting a horse saddle on it. The horse saddle was craftable using the following recipe:

The item ID used was 416, which refers to the armor stand in current versions.

32 horse saddles could be stacked in one slot.

Horse saddle items were later removed from the game in 13w18a, and normal saddles are now used for both pigs and horses.

Furniture


In Indev's terrain.png were two textures which might be interpreted as a chair (side and front). The actual purpose of those textures is unknown. The second texture may be the side view of a table, or possibly the front of the chair. On Notch's blog, The Word of Notch, furniture, and more specifically chairs, are mentioned a few times.

Studded armor


Studded armor were several sprites that were added sometime around Indev 0.31 in items.png. They were taken from Notch's unfinished game, Legend of the Chambered, along with other armor sprites. The armor was implemented into gameplay in early 0.31 and was eventually removed.

Quiver


In Legend of the Chambered (an abandoned RPG that Notch made), there was a quiver item available to be picked up as loot. Notch reused the sprite from that game and put it in Minecraft, albeit flipped horizontally. It was added in early 0.31 and eventually removed.

Although the sprite for the quiver has been in the game files since Indev, almost nothing is known about it. Jeb originally stated that there were no plans to add them. Later, during 1.9 development, Dinnerbone tweeted a 2×204960 image which can be reformed into a 854×480 Minecraft screenshot, containing the quiver. On June 30, 2015, Dinnerbone posted that he removed them again as arrows in the off-hand feel "more natural".

In 1.9, the quiver texture was removed.

Skis


A texture known in the game files as "skis.png" was added in 1.4.6 by Dinnerbone as a red herring. It was intended as a joke and only the texture ever existed; it never had an id, item, code in the game, and as confirmed by Dinnerbone, it could not be summoned. The texture was removed in 1.5.

Crying obsidian


Crying obsidian was a texture in Minecraft for an abandoned project to implement a spawn-point changing obelisk. It was abandoned after the introduction of beds. It would have been crafted with an obsidian block and lapis lazuli. The version in which the texture was added is not known.

The texture for crying obsidian was removed in Beta 1.5.

On February 9, 2012, Jeb was asked "Can you bring back Crying Obsidian or add some new color/texture blocks?" to which he responded "As soon as I've made preparations for more texture space."

Infinite water source


The infinite water source was a block that would create infinite water, which would replicate infinitely to fill up volumes. Mojang removed this because of problems and glitches when they were placed next to each other. They were added originally in Indev 0.31 (January 24, 2010) to allow for infinite lakes on floating maps.

It was available as block ID 52, prior to being replaced with the monster spawner in Infdev (June 25, 2010, 2). (Plus, it acted like Water in Classic.)

Infinite lava source


Similar to the infinite water source, the infinite lava source was a block that created infinite lava which would replicate infinitely to fill up volumes. It was also added in Indev 0.31 (January 24, 2010).

It was available as block ID 53, prior to being replaced with oak stairs in Infdev (June 29, 2010).



Locked chest
Locked chests were an April Fools block added in Beta 1.4. They would spawn rarely and emit a light level of 15. Pressing on the chest would bring up a screen, and clicking on the "Go to Store" button would forward you to the "Minecraft Store". They were subsequently removed from normal gameplay in Beta 1.4_01, but it remained within the game's code until it was removed entirely in 1.7.2.

It was available as block ID 95, prior to being replaced with stained glass in 13w41a.

Powered comparator
During the development for 1.5, the comparator at first used two separate block IDs to represent its powered and unpowered states, with names  and , and numeric IDs 149 and 150 respectively. As of 13w05a, the  block was removed from use in the game, replaced by a powered block state on the   block. It is removed completely in the 1.13 snapshot 17w47a, as of The Flattening.

Reverted potions
Before the 1.9 snapshot 15w31a, potions had a form known as "reverted". In the inventory, reverted potions looked identical to their base potion, much like mundane and mundane (extended), and their usage was also identical to their base potions, with the exception of turning into reverted potions rather than base potions. The only difference was data values.

There were two general methods to create reverted potions, one of which involved the addition of fermented spider eyes. Reversion, in general, referenced changing a longer, upgraded potion into its original weaker potion (for example, changing from a potion of poison (extended) into a potion of harming (reverted) by adding fermented spider eye).
 * The first method involved adding glowstone (typically) to an already upgraded tertiary potion. Since these tertiary potions have already been modified with redstone (typically), they could be changed to their original (revert) unmodified states depending on which modifier was added previously. Not all potions could be reverted (or react, for that matter) when glowstone powder or redstone dust was added to an upgraded tertiary potion (for example, adding redstone to an already redstone-extended potion did not yield a new potion).
 * The second method involved the addition of fermented spider eyes, followed by glowstone (usually). Method two worked by adding fermented spider eye to an extended positive potion (i.e. an extended tertiary potion). In almost all cases, this would corrupt the potion and produce a negative potion of equal strength (in this case, extended). Then, glowstone (depending on the recipe) was added to the extended negative potion. Since these negative tertiary potions (regardless of origin) have already been modified with redstone, the addition of glowstone would revert the potion to a potion of lesser duration.

A good example of this process at work is the reversion of the potion of weakness. A potion of weakness can be made two ways. The first method is by adding fermented spider eye to a mundane potion (water bottle + ghast tear/glistering melon/blaze powder/magma cream/sugar/spider eye), then adding redstone to produce potion of weakness (extended). The second method is by adding (again) fermented spider eye to either a potion of strength or a potion of regeneration. Potions of strength and regeneration, in their base or extended forms, will produce potions of weakness with equal magnitude (for the sake of this example, fermented spider eye is added to potion of strength (extended) to produce potion of weakness (extended)).

Now, there should be two Potions of Weakness (4:00). Glowstone dust could be added to the Potion of Weakness (Ext) which reverted the potion into a normal duration (1:30) Potion of Weakness. The act of reducing the duration from 4:00 to 1:30 was reversion.

Potions
There were 29 potions without effects that were left behind in. All unused potions had no effect and appeared to be re-textures of other potions. These potions were later removed in the 1.9 snapshot 15w44b.

These potions could only be obtained by using the command {{cmd|give @p minecraft:potion 1 ) in most commands, and uses only name IDs when assigning blocks to the inventory and save files. The old method of obtaining a block via numerical IDs is no longer an option. In addition, the game automatically removes blocks with illegitimate name IDs from the inventory, so using inventory editors is also no longer an option. Furthermore, certain blocks such as   cannot be obtained in their block form; however, since the game has a corresponding item named , the item form is given instead.

Obtainable until 1.7.2
In snapshot 13w37a, the command was modified so that it would notify the name of the item in chat. Due to this, 26 blocks were made unavailable:

Air block
The air block was briefly available as an item during 1.7.2 snapshot 13w38b, while Grum had been redefining the code that represented air in-game. This availability only lasted for one snapshot, as it was the focus of several bugs, most notably a bug that made mobs drop air upon death.

Obtainable until 1.8
In snapshot 14w25a, changes were made to the way the icons of items were rendered, and the way block data was internally represented. Due to this, 12 blocks were made unavailable:

Obtainable until 1.9
In snapshot 15w49a, 1 block was made unavailable:

Paeonia


Paeonias were unimplemented flowers that were replaced by the two-block-tall peonies.

There was only one screenshot of the block released by Jeb. Its texture file was still in the /texture/block folder and was named flower_paeonia.png, but it was later removed in the 17w47a snapshot for 1.13.

Chain armor
Since shortly after their introduction in Indev, and until snapshot 14w25a for release 1.8, chain armor was craftable using fire. As of that snapshot, fire can no longer exist as an inventory item, even with inventory editing, and the recipe itself was removed from the game's registry of recipes.

Chain armor may still be obtained in other ways.

Enchanted golden apple
Since their introduction in 1.3.1, and until snapshot 15w44a for release 1.9, enchanted golden apples had a crafting recipe: an apple surrounded by 8 gold blocks. Also, in Bedrock Edition, the recipe was removed in 1.2 build 1. In Legacy Console Edition the Enchanted golden apples are still craftable.

Enchanted golden apples may still be obtained in other ways.

Horse Armor
In the 13w16a snapshot of 1.6.1 a crafting recipe for horse armor was added. In snapshot 13w18a, the crafting recipe was removed.

Leather horse armor was added to the Pocket Edition just over three years later, and had a still usable but different crafting recipe.

Horse armor may still be obtained in other ways.

Brick pyramid


Brick pyramids were large and extremely rare structures that generated randomly in Infdev worlds in Infdev (February 27, 2010) onwards. These pyramids were completely solid; they had no interior rooms. These pyramids generated directly on top of the terrain instead of being a complete pyramid with the bottom underground (such as desert temples). Caves are also capable of generating inside these (only in Infdev (March 25, 2010). Brick Pyramids were removed in Infdev (March 27, 2010).

Indev House
The Indev House was a structure available in Indev versions. It was spawned in when the player first started a world.

When the player started a world in the original Indev version, the house would spawn in as a wooden plank house.

When the player started a world in version Indev 0.31 (January 24, 2010) to the beginning of Indev, a mossy cobblestone house with torches would spawn in and the player would have flint and steel in their hotbar.

These two houses had the floor made out of stone.

Obsidian wall
Obsidian walls were used in Infdev to mark the positions of the cardinal directions. This created two intersecting planes extending just above the surface of the solid material that surrounds them. This has long since been removed, as it was only found in Infdev (February 27, 2010).

Far Lands


The Far Lands was the area that formed the "edge" of the "infinite" map in Java Edition versions prior to Beta 1.8. They initiate about 12,550,820 blocks from the center of the world (0; 0) and have two kinds: Edge Far Lands (The Loop) and Corner Far Lands (The Stack), both feature extremely strange terrain. They are known to have several impacts to the gameplay, including floating-point precision errors and huge framerate/tickrate drops due to excessive coordinates, and the farther from the world center, the worse the effects, until the game freezes and crashes. Also, beyond X/Z 32,000,000, the chunks are just fake chunks, causing the player to fall through the terrain.

When mods like "The Cubic Chunks" Mod came out, a new set of Far Lands called the Sky Far Lands were discovered. When the height limit is removed completely, the Far Lands continue to generate upward till they eventually collide with the Sky Far Lands 25,101,640 blocks upward or to the Void Far Lands 25,101,640 blocks below the world.

In Beta 1.7.2 (and probably as far back as Alpha 1.2.0), there exist another set of Far Lands called the Farther Lands, which is found very recently after the discovery of the Far Lands, and generate 1,004,065,600 or so blocks away from the world center. This set combines with the previous Far Lands to create an even more strange mixture. In these sets of Far Lands, the terrain is very smooth and hardly changes its shape. This is especially noticeable in the Corner Farther Lands.

The Far Lands were fixed in Beta 1.8.

Trees
Some types of trees can no longer be grown with saplings, and no longer generate naturally in new terrain. They were often the result of the fact that new log and leaves types had not yet been added; new trees subsequently "borrowed" logs and leaves from other trees. For example: acacia trees, when they were first added, used jungle logs and oak leaves.

Glass Pillars
Glass pillars were added in Beta 1.9 Prerelease 3. They were used to mark the location of strongholds, as the eye of ender was not yet added. They were removed in Beta 1.9 Prerelease 4, due to the addition of the eye of ender.

Isometric screenshot
In the Indev versions of the game, you can take a screenshot of the map from an isometric perspective using F7. When the game captures an isometric image it will save the current location of all mobs and show any and all alterations to the map the player has made that would be visible from the perspective of the sun (at sunrise). The player will not be visible unless the player was in third person view before taking the Isometric screenshot.

The Isometric screenshot will save to your local user folder as "mc_map_####.png" where #### represents the number of the screenshot ranging from 0000 to 9999.

There are some limitations that existed with the screenshots:
 * Can only capture the player's model when in 3rd person mode.
 * Due to a glitch the screenshot will only render blocks that are in the player's FOV, and everything else will either be black or show blocks under the ground.

Indev map shape
The map shape is the general dimensions the level generator uses to create maps. Added in Indev 0.31, it alters the length, width, and height of the map. There are three kinds of shapes:


 * Square is a map of equal length and width, with a default height of 64.
 * Long is 2x the length and 1/2 the width of the specified map size.
 * Deep is 4x height and 1/2 the width and length of the specified map size.

A small, square map is 128x128 blocks wide, a normal square map is 256x256 blocks wide, and a huge square map is 512x512 blocks. All square and long maps are 64 blocks tall.

Indev map theme
A map theme (comparable to biomes) was the general style that the level generator used to create maps. Added in Indev 0.31 (January 7, 2010), it dramatically affects Indev mode's game mechanics. The Paradise and Woods themes were added in the Indev (February 14, 2010, 2). Themes became non-functional on Infdev (February 27, 2010), and they were later removed at a point between then and March 27, 2010.

There were four map themes:


 * Normal features sporadic trees, clouds and equal length of day and night. Ores can be found and lava is generated near bedrock.
 * Hell features less lighting allowing for mob spawning at all times, lava instead of water, dirt instead of grass and grass instead of sand. Mushrooms are abundant on the surface. Farming works at a much slower rate (one plant stage per day cycle). This was later replaced with The Nether.
 * Paradise features larger beaches and plentiful flora, the time is always set to "Noon" and hostile Mobs will only spawn underground. Farming works at a much faster rate (from planting to harvestable in 30–45 minutes).
 * Woods features constant overcast during the day that reduces light and higher tree density. Additionally, mushrooms are spotty throughout the overground areas.

Indev map type
The map type was the general format the level generator used to create maps. Added in 0.31, it dramatically affected Indev mode in the availability of water, sand, and gravel. Each map type was bordered by a grass or water flatland which stretched on for several thousand blocks. There were four map types:


 * Island is the default map type featuring minor hills and water as the border.
 * Floating contains multiple floating islands. Falling from these islands results in death as the surface is covered in solid water blocks. Floating gravel and sand is common, while water is rare.
 * Flat is similar to superflat today - it features flat grass with flowers and trees.
 * Inland features a slightly hilly landscape, which is essentially the Island map type with grassy flatland at its borders. Sand and gravel are common.

Winter mode


Winter mode was a randomly occurring map type for Minecraft Alpha. It was added in Alpha v1.0.4 and was the first "biome" other than the generic theme to appear in Minecraft, although not a true biome as it made the entire world snowy. It was removed in Alpha v1.2.0. Four different types of snowflakes fell constantly, creating snow tiles on any solid block that was directly exposed to the sky. When a map was generated, all exposed water blocks would be frozen into ice. Also, animals would not spawn as much as in the normal world. It is possible to convert worlds generated before Alpha v1.2.0 into Winter mode by using a NBT editor.

Pre-Beta 1.8 biomes
In Beta 1.8, biomes received a major overhaul, removing and changing many biomes. Prior to these changes, there were 13 biome types which were much smaller and less distinct.

Customized world type
Customized was a world type that gave control over many settings that affected terrain generation, such as ores, sea level, biomes, structures, and many variables that govern the random shape of the terrain. It was introduced in snapshot 14w17a for 1.8, and was removed in snapshot 18w06a for 1.13.

Beast Boy, Black Steve, Steve and Rana
Beast Boy, Black Steve, Steve and Rana were human mobs originally in-game as a test during the Indev phase. They were made by "Dock", Minecraft's past artist, and were removed from the game when Dock left the development team in early 2010. These mobs had no animation and glided around in the same pose. Upon death, all of them except Rana could drop 0–2, 0–2 s, 0–2 (this item has since been renamed "gunpowder") and 0–1. Beast Boy, Black Steve, Steve had HP. Rana had HP. Beast Boy is a DC superhero and member of the Teen Titans, and Rana is an original character of Dock. "Rana" means frog in Latin. When hurt, these mobs make The Player's hurt noise.

If you look closely at the Indev versions with these mobs, you will notice that Rana is never in any of the same versions as Beast Boy, Black Steve, and Steve. They are always in separate versions.

Human


Humans were hostile mobs with the default skin. In Classic, humans could be spawned by pressing .They did not have a punching animation like the player; they only ran into the player like a zombie would.

In classic, humans would just move around the map aimlessly, walking in slightly imperfect circles, flailing their arms and heads, and jumping occasionally. They could not move or destroy blocks, and were not affected by liquids. Changing a player's skin would not change the skin of the human mob.

Pigman texture


Minecraft user Miclee came up with the idea for pigmen. He was given the Bacon Cape as a reward, but when Notch was asked for personal capes by other users, the Bacon Cape was taken away from Miclee to prevent further commotion.

Notch mentioned in April 25, 2011 that he might add pigmen as villages' townspeople, although in the Beta 1.9 pre-releases, a different villager mob was introduced.

In 1.6.2, the texture file was removed.

Fluff.png
In Infdev, a texture called "Fluff.png" was added. It was used as a texture for clouds in Infdev, but was later removed in early alpha.

waterterrain.png
In Infdev, a file similar to terrain, referred to as "waterterrain.png" could be found, it is unknown when this file had been added, and unknown when it was removed. It appeared to be some sort of arrow system, and it is possible this was used to test water animation.

Door Details
In the Infdev terrain file there could be found two door textures that looked exactly the same except the hinges and the handle were on the opposite sides, but in today's Minecraft only one of the texture is used, and is flipped, when the handles and hinges are on the other sides. The alternate door was overwritten with the iron door texture in Alpha v1.0.1.

Door Entity
In the Infdev "item" folder (where signs, arrows, and minecarts could be found at the time), a file named "door.png" could also be found. It was most likely going to be used for the door animation Notch had been wanting to add.

Brick Block Variations
At some point in Classic, there were 4 similar brick textures added with slight differences, hinting it might have been planned to add variations in textures.

Steve Villager Hybrid
After villagers were added, a strange file could be found in the mobs folder (outside of the villager folder) called "villager.png". It appeared to be some sort of Steve villager hybrid. This file was removed in 1.5 during the texture pack reform.

Steve's hair on 2nd layer of char.png
Char.png can be found on 0.27 SURVIVAL TEST's texture files and Steve's hair is on the 2nd layer rather than the 1st. It is unknown why this switch occurred. This was possibly a failed hair test.

Another failed skin attempt on char.png
Char_2.png can be found on Indev (February 12, 2010, 1)'s texture files. This was possibly another failed attempt of testing skins in Indev, there are two gold pixels on the top right of Steve's head for unknown reasons and another layer of hair.

"chunkinfo" command
From 1.8 (14w30a) to 1.13 (17w45a), the file  contained translation strings for a   command, which never existed in game. The following keys existed:

commands.chunkinfo.usage=/chunkinfo [  ] commands.chunkinfo.location=Chunk location: (%s, %s, %s) commands.chunkinfo.noChunk=No chunk found at chunk position %s, %s, %s commands.chunkinfo.notEmpty=Chunk is not empty. commands.chunkinfo.empty=Chunk is empty. commands.chunkinfo.notCompiled=Chunk is not compiled. commands.chunkinfo.compiled=Chunk is compiled. commands.chunkinfo.hasNoRenderableLayers=Chunk has no renderable layers. commands.chunkinfo.hasLayers=Chunk has layers: %s commands.chunkinfo.isEmpty=Chunk has empty layers: %s commands.chunkinfo.vertices=%s layer's buffer contains %s vertices commands.chunkinfo.data=First 64 vertices are: %s

It is unknown if this command was used by Mojang for development or was simply a dropped feature.

Footstep particle
The footstep particle was introduced, but never used in the game. It was removed in snapshot 17w47a, as part of the The Flattening.

Gear


On January 25, 2010, Notch posted a video of the gears being placed onto the wall of a cliff.

In Indev on January 26, 2010, the code for gears was added. It could only be obtained by inventory editing and was initially invisible in the inventory, at some point this was changed to the animated version as seen when placed in the world. When edited into the game, gears could be placed anywhere, but would only display on a side of any solid block. Placing them in a space where more than one side are next to each other would cause a gear to appear on all of the sides. Placed gears were almost impossible to destroy; any mining directed at a gear phased through to the block behind it, much like water. If the block a gear was on was destroyed, the gear was not removed, but oddly, was invisible. The gear still existed in the map and would show up again if a solid block was replaced. Gears could therefore only be removed using a liquid to flow on them. A gear's sprite consisted of two parts; the center rod and the animated gear.

In early Alpha, gears were removed. They had a data value of 55, which was replaced by redstone in Alpha v1.0.1.

Play Tutorial Level button
An unclickable Play Tutorial Level button was added during Indev. It could be found on the main screen. However, there was no tutorial level in the games code. It was finally removed during the transition from Alpha to Beta stage.

calm4.ogg


calm4.ogg was a music file (alongside the other tracks) that was beta-tested and created by Notch himself. The song is 3:13.

It consists of an up-beat synth, battle-like tune. At 1:36 in the song, you can hear Notch saying "Mojang Specifications" in slow-motion.

The track was released around. As such, players who had the game while the song was still in it will continue to hear it being played, as the game will play any song in the  folder. In Alpha v1.1.2 this track was omitted from the downloaded game files.

With the introduction of the 1.6.1 launcher, playing older versions with the track Calm4.ogg will not allow the track to be heard, since music is downloaded separately from the .jar files.

Player stats
In an early Indev version, the player could open the inventory screen and view their name and three stats: "ATK", "DEF," and "SPD". These only existed for a very brief period of time - when asked, Notch stated he could not remember exactly why they were implemented and subsequently removed, and he assumed they were placeholders for "vague plans".

Version Number Displayed During Gameplay
Starting with 0.0.9a, all versions from then until release candidate RC2, text was displayed in the top left corner of the screen, which told what version the player was on. Versions between Beta 1.6.4 and Beta 1.7.3 did not have this text. From 0.0.9a to the last Indev 0.31 release (Indev 0.31 (February 5, 2010)), only the version number was displayed. But after Indev switched from being 0.31 to being called Minecraft Indev (Indev (February 6, 2010)), the word "Minecraft" was shown before the version number. In the Alpha development stage, the text read Minecraft Alpha v#.#.#(_#). In the Beta development stage, the text read Minecraft Beta #.#(_#). This feature was only partially removed, for, among other things, the version number can now be shown by pressing the while playing the game (thus displaying the version number as a part of the debug screen). It never appeared on the menu screen until after Beta 1.0, which continues to the present day.

Unlicensed Copy Message
In the Beta stage of Minecraft's development, a message reading "Minecraft Beta #.#.# (_0#) Unlicensed Copy :( (Or logged in from another location). Purchase at minecraft.net," was shown. This message can only be seen in versions between Beta 1.6 Test Build 3 and Beta 1.7.3, as proved by a bytecode editor. The bytecode for the message was removed in Beta 1.8.

Loading Screen
From Infdev (June 29, 2010) to Alpha v1.0.3, a screen that read "loading..." in the bottom left corner could be seen when launching the game. This was replaced in Alpha v1.0.4 with the Mojang logo screen.

Achievements
Achievements were available between Beta 1.5 and 1.12 (17w06a). They were ultimately replaced by advancements, though editions other than the Java Edition still have achievements instead.

Texture pack
Texture packs were added in Alpha v1.2.2, and were replaced with Resource packs in 1.6.1 (13w24a).

3D Anaglyph
3D Anaglyph is an option in video settings that applies an red-cyan stereoscopic effect, and when wearing 3D glasses, can actually see different parts of the game in varying depths, making the world "pop out". In the 1.13 snapshot 17w43a, 3D Anaglyph was removed for unknown reasons.

Void fog


In Beta 1.8, black void fog and the  particle were introduced. As the player descended below y=17 in The Overworld, the void fog and particles would start to appear. As the player traveled deeper, the fog at the edge of the render distance would become closer until the player reached bedrock, where visibility was reduced to just a few blocks, beyond which was complete darkness. The gray void particles appeared at and under layer 16, as well as in the void.

The void fog was removed in snapshot 14w34c, the main reason being to improve perfomance. The  particle was also removed from the void, but stayed in the game until snapshot 17w47a when it was removed as part of The Flattening.

Minecart changes
In snapshot 14w11a during the development of 1.8, the physics of minecarts were changed. Their collision and position handling was improved, and they could go faster and farther, derail at corners if going too fast and refuse to go uphill. However, these changes were reverted in 14w17a after the developers decided that the behavior was too buggy.

Dispensing command blocks
From 1.8 snapshot 14w07a, dispensers had the ability to place a command block that it contained, when activated. This feature was removed as of version 1.8.6 to solve a security issue.

Mobs running from creepers
In 1.8, mobs ran away from creepers that were about to explode. In 1.8.1-pre1, this feature was removed because every mob that had the ability to run from a creeper was looking for an exploding creeper every tick, degrading performance.

Splashes
When a splash is removed, the line it occupied in splashes.txt is deleted, meaning the line number of all subsequent splashes lowers by one. (Note: the file containing splashes in Bedrock Edition is splashes.json.)

Super Secret Settings
The "Super Secret Settings", added in 1.7.2 snapshot 13w38a, were removed in 1.9 snapshot 15w31a for an internal rewrite. It was a button under the options menu that, when pressed, would blare a random game sound with a lower pitch, and activate a shader.

Native Twitch.tv integration
Native Twitch.tv integration, added in 1.7.4 snapshot 13w47a, was removed in 1.9 snapshot 15w31a. Twitch chat was integrated into the game.

entity.hanging.place and entity.hanging.pop
and were two sound effects added in 15w49a and removed in the next snapshot, 15w49b.

Old conduit particle
The Conduit was added in the 18w15a snapshot with particles, but those particles were changed in the next snapshot 18w16a.

Tags
The  and   was added in 1.13 snapshots 18w07a and 18w07b respectively and removed in 18w10c. Before the removal, these tags functions follows: