Fence

Fences are wooden wall blocks added in the Seecret Friday update 8, version 1.0.17 Alpha. 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.

A fence occupies the center space of blocks and automatically connects to any solid block that is placed next to it. Fences are broken most quickly with an axe.

Fences also have a wide use of enclosing animals, such as pigs, chickens, cows, and sheep.

Since the 13w16a snapshot, fence posts can be used to hitch mobs with a Leash.

Crafting

 * Three (3) blocks (logs) of wood will make eight (8) fence sections with no leftover sticks. Similarly, 24 logs will make a stack of fences.

Occurrence

 * 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.

Uses
A fence's primary use is for enclosing an area. Functionally, the fence serves to keep mobs and players either inside or outside. A wide area can be made monster-resistant by enclosing it in fences and lighting the inside portion heavily. This stops any monsters from spawning within the fence, and stops most monsters which spawned outside the fence from coming in; the exception is spiders, which can climb over it. In addition, while skeletons are unable to cross a fence, they can shoot over it; also, if there is not a roof, Endermen can still teleport in.

Fences can also be used as railings, especially on the edges of balconies, bridges, or floating platforms. Since fences cannot be jumped over, this keeps players and mobs from falling off while still allowing them to easily see past the fence. If there is water at some distance, they can easily be fished over, by aiming above the horizon level.

Fences can replace glass for windows, as mobs cannot see through them. Unlike glass, fences can be moved around trivially, and are easily renewable.

Fences are excellent for building underwater bases. They use 3/4 as much wood as wooden plank walls, provide outside visibility, and create a breathing space on the outside, which simplifies construction immensely. Fence ceilings also do not "drip" water. Leaving an outside wall corner open creates a waterproof door you can use, as long as both the wall ends in question are made of fence.

Single fences can also be used as freestanding diving bells; place a soft block such as sand, put the fencepost on top, dig out the block and you have an air bubble at head height. Optionally, embed a Jack 'o' Lantern in the ground underneath for visibility.

Fences can be used for an effective water elevator, with a 2x2 shaft have the water in front and the fence posts stacked behind. This also acts as a source of air underwater, as fences are not a full solid block.

By surrounding a platform with floor-level fences and putting a two-block-high ceiling above, you can make a platform that is impossible to walk off of yet provides an unobstructed view (or field of fire). Ideally, this platform should be made for top-half slabs, since that way the fences will not attach to the platform.

If short of buckets, a single fence can be used to cap a leaking water or lava source. This leaves the capped fluid still visible, preventing a forgetful player (or, in SMP, another player) from later mistaking the cap for a stray block and mining it. It also allows capped lava to still provide illumination. However, since lava burns fences, lava springs can only be capped temporarily unless you use cobblestone wall or nether brick fence instead.

Fences can be made into a bridge by making a 3-5 wide set of Fences in front of a ledge or shore, with more fences for railings, and pressure plates in the center to walk on.

Because fences are 1.5 blocks high, they can be used with other blocks to create shallow stairs (the kind you can sprint up). They have the advantage of allowing a view through the stairs, in case of a monster lurking underneath.

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.

Fencing tips

 * To craft one stack of fences you need 24 logs. This produces three stacks of sticks, which can be made into one stack of fences.
 * The following does not account for gates, or extra fences needed for blocking jump routes (see below):
 * To enclose an area of L&times;W in size (L being length and W being width), you will need enough fences for the entire perimeter P, which will be double the sum of length and width, give or take 4 for the corners. If L and W do not include the fences, this will be P = 2L + 2W + 4.  If they do, then P = 2L + 2W - 4.  A classic 9&times;9 farmland plot will take 40 fences to surround.
 * To fence a length of minecart track, you will need double the number of fences as you placed rails. (If you used 2 stacks of rails, you will need 4 stacks of fences.)  This doesn't depend on how far from the rails your fences are, nor are diagonal runs any different.
 * Watch out for nearby blocks outside the fence, from which monsters could jump onto the fence and then over. If you're not sure about a spot, try the jump yourself.
 * Any block next to, or one space away from, the fence, is an obvious hazard. Remove the blocks, replace them with slabs, stairs,  etc, or make the fence higher.
 * For similar reasons, any time your fence goes downhill by one block, make the downhill side two-high for at least two blocks.
 * A less obvious problem: If you build a two-high fence next to 1-high blocks, a monster (or you) can step from those blocks, up a half-block to the lower row of fence (where it joins the blocks), then jump up one block up to the top of the fence.
 * If you are roofing over only part of an fenced enclosure, or your railway is going through a shallow tunnel, you will need to fence off the overhanging roof, to keep monsters from jumping down. (Also, you may need to light or fence off the roof itself.)
 * Trying to build a fence around a lava pit is not a good idea, as the fence will catch fire if placed on the block directly adjacent to the lava. Fences can also be set afire by lava several blocks below ground level.
 * Keep in mind that wooden fences will not attach themselves to most transparent blocks, with the exception of other wooden fences and fence gates. Thus they will not attach to other sorts of fence (nether brick fences, iron bars, cobblestone walls, glass panes), stairs, single slabs, or doors.  Likewise, they will not attach to glass, ice, pumpkins/jack-o-lanterns, chests or anvils.  However, the gaps produced can be useful:  e.g., the gap between a fence and a door is too narrow for even cave spiders to pass, but the player can attack through it.
 * To make sure that a complex fence system is secure, wait for nightfall inside the fence, look for a zombie outside the fence, and try leading it around your perimeter. If it starts heading for a spot other than just the point closest to you, it means that a path to you does exist and he's spotted it.  (Watch out for other mobs trying to join the fun, and keep your bow handy.)
 * Mobs cannot path through the gap between two diagonal fences. However, other mobs can push them through such a gap, so your animal pens still need corner pieces.

History


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.