World border

The world border is the edge of the current Minecraft World. The default center is at 0,0 , with a width and length of 60 million (60000000) blocks from both ends. However, with commands, it can be modified to become smaller, have its center shifted, and more.

The world border appears as animated, diagonal, narrow stripes. When the border is not moving, the stripes are translucent aqua. If the border is expanding, the stripes appear green, and if the border is contracting, the lines appear red.

Effects
While most entities cannot move through the world border, shot arrows, thrown snowballs, thrown eggs, and thrown ender pearls can still pass through the border. The world border always behaves in full block increments, even if it is set to a partial block. The world border's dimensions and location are the same across all three dimensions, but it's effects stop happening at around Y=1E33, even though it stops displaying below Y=1 and above Y=256.

If a player is on the wrong side of the world border, they will normally take damage unless in creative mode. While players cannot move through the world border, they can reach the other side of the world border through other means, including:
 * Letting the world border pass them as it is shrinking
 * Throwing an ender pearl through the world border
 * Mounting a minecart, boat, horse, or pig
 * Dismounting anything at the north or west edge of the border
 * Using commands such as.
 * Sleeping next to the world border

Players normally cannot place and destroy blocks (other than lily pads ) nor interact with objects outside the world border; though players can place blocks outside the world border by placing the block against a torch that is inside the world border, or using commands. Most blocks still function outside the world border, such as water and lava which will still flow through it, and most redstone which will still function. Exceptions include falling blocks, which will drop as a resource, and pistons or hoppers, which will simply not function. Explosions also work normally outside of the border, allowing them to still alter terrain, and light is unaffected.

Commands

 * Set
 * Sets the border to a square region with the specified size in blocks as the width and length. Optionally, a timeInSeconds may be specified such that the border grows or shrinks from the previous width to that being set over the specified time in seconds. If timeInSeconds is not specified, the world border changes immediately. To reset the world border size, set sizeInBlocks to 60000000 (sixty million). The border will still grow or shrink and the animation will display even if the game is paused.
 * Sets the border to a square region with the specified size in blocks as the width and length. Optionally, a timeInSeconds may be specified such that the border grows or shrinks from the previous width to that being set over the specified time in seconds. If timeInSeconds is not specified, the world border changes immediately. To reset the world border size, set sizeInBlocks to 60000000 (sixty million). The border will still grow or shrink and the animation will display even if the game is paused.


 * Center
 * Sets the center of the area inside the world border to the specified  and  coordinates. Tilde (~) can be used as a relative coordinate. To reset the world border center, set both  and  to 0 (zero).
 * Sets the center of the area inside the world border to the specified  and  coordinates. Tilde (~) can be used as a relative coordinate. To reset the world border center, set both  and  to 0 (zero).


 * Add
 * Adds or subtracts sizeInBlocks to/from the current world border width and length. sizeInBlocks may be a positive or negative number. Optionally, a timeInSeconds may be specified such that the border grows or shrinks from the current width to that being set over the specified time in seconds.
 * Adds or subtracts sizeInBlocks to/from the current world border width and length. sizeInBlocks may be a positive or negative number. Optionally, a timeInSeconds may be specified such that the border grows or shrinks from the current width to that being set over the specified time in seconds.


 * Damage
 * Sets the amount of blocks a player may safely be outside the world border before taking damage. The default is 5 blocks.
 * Sets the amount of blocks a player may safely be outside the world border before taking damage. The default is 5 blocks.


 * Sets the amount of damage a player takes when outside the world border plus the world border buffer. The default is 0.2 damage per second per block.
 * Sets the amount of damage a player takes when outside the world border plus the world border buffer. The default is 0.2 damage per second per block.


 * Warning
 * Causes the screen to be tinted red when a contracting world border will reach the player within the specified time. The default is 15 seconds. The tint will not display if the user is using fast graphics.
 * Causes the screen to be tinted red when a contracting world border will reach the player within the specified time. The default is 15 seconds. The tint will not display if the user is using fast graphics.


 * Causes the screen to be tinted red when the player is within the specified number of blocks from the world border. The default is 5 blocks. The tint will not display if the user is using fast graphics.
 * Causes the screen to be tinted red when the player is within the specified number of blocks from the world border. The default is 5 blocks. The tint will not display if the user is using fast graphics.


 * Get
 * Returns the current width of the world border.
 * Returns the current width of the world border.

History
See World boundary for all the different effects of the world boundary prior to the introduction of the world border.

Trivia

 * The "shimmery" texture was made by Ryan Holtz.
 * The reason the world border is at X/Z ±29,999,984 is that Dinnerbone put it 1 chunk short of that edge to prevent falling through the world.
 * If a dispenser or dropper is placed so its "face" is right up against the edge of the border, items, projectiles, TNT, etc. can be fired from the dispenser/dropper outside of the edge of the border.


 * If a mob is spawned from a dispenser with a spawn egg inside, the mob can be killed, but cannot move and is not affected by gravity. The same applies for dispensed items;they will float in midair. If an item is dropped from the player inventory, the item will fall until it hits the ground.


 * There is a single buildable layer outside the world border; you can place a block outside of the border by building off the hitbox of a block on the inside.


 * Liquids can flow through the border and will continue flowing until they reach their flow limit. Liquids can also be placed on the outside of the border, but they do not flow. Liquids placed via a dispenser will flow as normal. Through a dispenser, placing water and then lava, or vice versa, will result in the flow abruptly ending, presumably because the obsidian that would normally spawn won't spawn.