Fence

Fences are wooden wall blocks. They count as one and a half blocks tall for player/mob collision, and one block tall for all other purposes. This prevents players and mobs from jumping over them, while using only one actual block space.

Obtaining
Fences are broken most quickly with an axe.

Natural Occurrence
Currently only the oak fence spawns naturally:


 * Fences form the uprights for the supports in Abandoned Mine Shafts, where they are plentiful.
 * They are also found in NPC Villages, where they appear in tables, lampposts, and even enclosures on roofs or behind buildings.
 * Fences occur in library rooms of Strongholds as railings and chandeliers. In the latter case, there are many Torches attached to them.
 * Fences appear on the "patios" and in the front window of Witch Huts

Usage
While fences appear to be a single block tall, they are actually 1.5 blocks tall, meaning most mobs cannot jump over them. Because of this, they can be used as a barrier against mobs. They can also be used as a form of window, since the player can see through the gaps in the fence.

A fence occupies the center space of blocks and automatically connects to any solid block that is placed next to it. Since their hitbox is smaller than a single block, it will allow a mob in the block to breathe even when submerged.

Fences can be used to hitch mobs with a lead.

Fences can also be used to fuel a furnace, although the player would have been better off burning the wooden planks used to create them.

Original fence stacking


When first implemented, the game prevented blocks from being placed above the fence but allowed the fence to be placed on a location when there is a block above it. This loophole was soon commonly exploited to allow fences to be stacked, mainly for aesthetic purposes.

The stacking process was done by creating a wall of blocks one layer shorter than the intended height of the fence and working down. Removing blocks from underneath the fence did not cause it to collapse like cacti and doors, so the lower layers of the wall could be replaced by fences easily, one-by-one. These rules were not applied underwater so they could be stacked just like any other block when submerged.

Before the official release of Minecraft, fence corners did not need to be complete in order to be sealed. A corner where two directions meet at a right angle could be created without the actual corner piece. This would create two separate fences which terminate next to each other without actually touching. While there is a visible gap, players and mobs will still be unable to pass through. This feature could be used to create lengths of diagonal fences, which will appear as nothing but posts, yet will still prevent anything from passing. However, in 1.0.0, the fence's collision box was fit around the fence itself (except for the 1.5 height), thus requiring the corner fence.

Trivia

 * If a carpet is placed on top of a fence, a player can jump onto the carpet, while mobs cannot (and won't even try). This is safer than a gate that might be left open, but it also can't be opened to mobs short of breaking it.
 * If you try to use an item with a right-click function while looking at a fence, the item will not perform its function but will instead appear to be attempting to mine the fence. The fence will never break from this "mining".
 * Getting hit by someone else (or shooting yourself with a knockback enchanted bow while sprinting forwards) while in midair can cause the knockback to propel you over the fence (this works with other blocks that are 1.5 blocks tall.)