Cobweb

Cobwebs are blocks that slow down movement.

Obtaining
Cobwebs can be obtained by clipping them with shears. One will also drop itself if broken with a sword enchanted with Silk Touch. A cobweb will drop one piece of string if broken with a non-Silk Touch sword or if water touches or flows over it or a piston pushes it. It will drop nothing when broken using anything else.

Natural generation
Cobwebs generate naturally in stronghold libraries, igloo basements, abandoned mineshafts and woodland mansion spider spawner rooms. Cobwebs also generate in zombie villages.

Usage
Mobs can spawn inside of cobwebs, in which case they will not catch fire if they are caught in a cobweb. They also diffuse sky light.

Blocks can be placed on cobwebs. Paintings and signs can be placed on their sides, or on top in the case of signs.

Redstone circuits


Cobwebs can be used as a delaying mechanism in a redstone circuit, for example to delay an item falling on a pressure plate or into a hopper.

Effects
All mobs that move through cobwebs will slow down, with the exceptions of spiders and cave spiders. Mobs falling through cobwebs will take 13 seconds to move down 1 block. They will partially stop blast damage if a player and the TNT/creeper/etc. are both caught in the cobweb. The slowing effect of the cobweb will increase if it is placed on ice.

A cobweb affects the player's movement abilities, as well. While in contact with it, the player will move at a speed of about 15% of the normal walking speed. Additionally, jumping will vibrate the player akin to jumping in a 2-block-high space. A cobweb also limits the rate at which a player can break blocks. Like water, falling into a cobweb will prevent a player from taking fall damage, meaning a fatal fall can be mitigated with cobwebs. Attacking while falling through a cobweb counts as a critical hit, the same as when falling after a jump.

Items thrown into a cobweb are slowed and will fall through it after a maximum of about 24 seconds depending on where it enters. They will not merge with other items of the same type thrown on the ground.

Cobwebs have different effects on moving entities. A falling block that falls or is shot into a cobweb will slow down, then drop as an item after about 4 seconds. A shot arrow will pass through cobwebs without being slowed.

A minecart with no players in it takes about 9 seconds to fall through a cobweb if a rail is placed directly under the cobweb, however if there is air between the cobweb and the rail, the minecart takes about 34 seconds to fall. Every extra cobweb added will give an additional 25 seconds of falling time. Players are unaffected by cobwebs when in a minecart unless they come into direct contact.