Soul Sand

Soul Sand (aka Slow sand, Mud, Hell mud or Nethermud) is a brown-grey dirt-type block, found in The Nether. This material has looks somewhat similar to a Dirt block, but it has some unique features. It slows the movement of any player or mob, and players sink slightly into the block while walking on it. This effect is much greater when the Soul Sand block is placed in water and could be useful for making drowning traps more effective against mobs. The slowing effect can also be used to fight large amounts of mobs at once, especially using a bow.

[[File:Oneway.jpg|200px|thumb|left|A one-way passage. Players cannot pass through the side with the soul sand.

After the 1.3_01 Beta update was released, players could no longer build these doors.]]

When placed on the ground in front of a two-block high ceiling, soul sand prevents players from going through it from the front, making it useful for making one-way passages or invisible barriers. This affects mobs too as they have to jump to get out of the slowing effects of the block and thus unable to get through the door. However, it is possible to move through the opposite side of the one-way door by jumping over the soul sand and squeezing into the one way door. Since the soul sand causes you to sink into the block slightly, it causes the player/mob to not be able to enter through the door, but if you do not sink into the soul sand, it is like jumping over an empty space. It is also possible for a mob to jump over this, as well. But that is unlikely, since a mob usually only jumps when there is a brick one level higher than the mob. A good way to overcome this problem is to simply expand the soul sand so it covers a larger area, rather than one brick.

Because minecart tracks can be laid on Soul Sand like most other block materials, this quirk can be exploited to create one-way gates for minecarts to pass through. This is one of the few ways to allow minecart tracks to go directly inside a secure area without risking wandering mobs getting in.

When jumping into a one-way entrance from a block that is not soul sand, the player (or mob) can get through. This can be fixed by removing the block behind the soul sand, having three, instead of one, block of soul sand behind the door or building up walls on both sides. The image shown with the one-way entrance can be passed using this bug.

A player (or mob) can also get through when riding a Minecart

A player cannot walk from a block of soul sand to a step without jumping.

This block also suppresses the impact from Boats when colliding to it at the angle of approximately 6° to 174°. This makes it an effective building material when creating a dock.

While placed directly over an ice block, this block's slow effect is greatly increased. This affects both mobs and players.

This block will also prevent water currents from transporting items over it. An example is where used in a cannon to stop water from moving the TNT.

It is commonly mistaken that the best tool for harvesting soul sand is to be a shovel because harvesting it makes the same sound as dirt, gravel and sand. However, shovels make no effect in speeding up the process. Swords can harvest it slightly faster, but this costs two uses of the sword instead of one.

Trivia

 * The texture resembles a collage of faces. These faces look like those of Creepers.
 * The first appearance of this block was on Notch's blog.
 * There is currently a bug where falling off this block directly into lava or water will make the player move slower in said lava/water until you are back on normal land.
 * When first released, Sneaking on a soul sand block would not prevent the player from falling from the block. This bug was fixed in the 1.2.1 Alpha patch.
 * Soulsand is 15/16 the height of a normal block.
 * Soulsand no longer can work as a 1 way door as of 1.3_01