Anvil

"Anvils!. Your sword can now be a "Dragon's Tooth" if you want, or you could just repair it a little."

- The Pretty Scary Update Promo Poster

Anvils are blocks that use the item repair interface to repair and rename items, and combine enchantments. Anvils use a complex experience and material cost system, which checks for how tools are positioned, and how many times they are repaired. For full details, see anvil mechanics.

Obtaining
An anvil can be mined using any pickaxe. If mined without a pickaxe, it will drop nothing.

Usage
Anvils can be used to repair tools and armor, enchant items with enchanted books, and rename items and blocks. All of their functions cost experience levels (earned by performing certain actions), and material costs.

Anvils are damaged by using it for repairing (also by falling, see below) and will eventually be destroyed by such use. With each normal use anvils have a 12% chance of being damaged. The first two times an anvil is damaged, its texture will change, and (if picked up) its tool tip will identify it as "slightly damaged" the first time, or "very damaged" the second. If a "very damaged" anvil is again damaged, it will disappear. If it was being used, the GUI will close and the forged item will be dropped on the ground as the anvil disappears. On average, an anvil will survive for 24 uses; pro-rating the 31 iron ingots used to make it, gives an average cost of 1.292 iron ingots per use.

Anvils are affected by gravity similar to sand, gravel, and dragon eggs: If the block under them is removed, or if they are placed atop air, they will fall. A placed anvil cannot be pushed or pulled by pistons, but a falling anvil (one in entity form) can. Falling anvils can do considerable amounts of damage to mobs or players, so they can be used in traps. An anvil has a chance to be damaged by the fall, equal to (5 + distance&times;5)%.

Repairing and renaming
Anvils have two modes to repair items with durability:
 * A player can combine two similar items in the crafting grid (swords for example), the target will keep its enchantments, and may gain new ones from the sacrificed item.
 * Or a player can use materials respective to the item (iron ingots for iron items with durability, diamonds for diamond items with durability). One material can only repair 25% of the target's maximum durability.

In addition, the player can rename any item - not just items with durability - using an anvil.

How to repair


Place the target item on the left slot. On the right, place either a matching item (the sacrifice), or one or more pieces of the item's raw material. The anvil will then tell you how many levels this repair will cost. Also, the result slot will show the item as it would be when repaired, including tooltips showing its enchantments and in + mode, its durability. To actually repair, remove the result item from the result slot and put it in your inventory, or throw it on the ground. (Naturally, you can't do this unless you have enough levels, or are in creative mode.) Both input items will vanish when you take the result item.

Repairing with materials works for the most part, but not with all items: As a rule of thumb, it works for items with their material in the default name, like iron pickaxe, so it can be done with swords, pickaxes, armor, etc., but not with bows and shears. As a special case, chain armor can be repaired with iron ingots. The repair does not need to be complete; one material will only repair 25% of the item's maximum durability.

Repairing with a matching item works for any item with durability including bows, shears and so on. The items must match in type; you cannot combine a golden pickaxe with an iron one. When sacrificing an item for repair, the sacrifice's remaining durability will be added to the target, along with a bonus of 12%.

Note that in both cases the resulting durability will be limited to the item's maximum, and there is no discount for "over-repair": You pay one level per unit of material used, or two levels for the sacrifice, regardless of the resulting durability, even if it would exceed 100%.

As a subset of repairing one item with another, the anvil can transfer enchantments from the sacrifice to the target. Two Sharpness II swords can be combined to make a Sharpness III sword, or a pickaxe with Efficiency can be combined with one that has Unbreaking. This can produce enchantments and combinations that could not be made by using an enchanting table. But even so, some enchantments cannot be combined if it is similar, or contradicting, in context of what it does (such as Sharpness and Smite, Protection and Projectile Protection, and Fortune and Silk Touch). If the target is damaged, you will pay for the repair as well as the transfer.

Transferring high-level enchantments is more expensive, and renaming an item has an additional surcharge. To boot, repeatedly repairing an item gives a cumulative penalty. The anvil has a limit of 39 levels, beyond which it will refuse to repair altogether. This limit is not present in creative mode. In some cases it may be possible to do things piece-wise (rename, repair, then transfer enchantments). For full details of the anvil's costs and restrictions, see the Anvil mechanics page.

Renaming
Any item or stack of items can be renamed at a cost of one level plus any prior-work penalty. If only renaming, the maximum total cost is 39 levels. Renamed tools and renamed mobs from renamed spawn eggs will show in death messages. Renamed mobs will show their name when your cursor is on them. Renamed command blocks will use their name instead of "[@]". This feature is also used, in two different ways, to produce a named monster: Firstly, it is the only way to assign the desired name for a name tag. Secondly, if a spawn egg is available (from creative mode or provided from an adventure map), any name given to the spawn egg will be kept by the mob it produces. If a renamed block is placed on the ground (or anywhere in the world), and then mined, it will lose its given name and will go back to its original one. The maximum length for renaming is 30 characters.

Enchanted books
Enchanted books themselves can be combined to create higher tiered books. Which are used as stated below.

Enchanted books are used to enchant an item with an anvil, with the book acting as the sacrifice. The regular enchanting rules still apply, but with significant discount to the cost. In creative mode any item can be enchanted this way (for example: even a Silk Touch stick), but even then, incompatible enchantments will not be combined.

Falling anvils
When there are air blocks below anvils, they will fall. Anvils will make a metallic clanging sound when they land.

When anvils land on a non-solid block, they destroy the non-solid block rather than dropping as an item, unlike Gravel or Sand. When an anvil is dropped on pressure plates, boats, cobwebs, slabs, signs, cakes, lily pads, opened fence gates, or closed trapdoors that do not have a block beneath them, the anvil will drop itself as an item. When dropped on a mob head, the mob head will become the item form.

Falling anvils, when they fall on a player or mob, will damage them. Damage amount depends on fall distance: per block fallen after the first (e.g., an anvil that falls 4 blocks will deal  damage). The damage is capped at, no matter how far the anvil falls. Wearing a helmet will reduce the damage by 25%, but this costs durability on said helmet. When a player dies by an anvil falling on them, the chat will display this message: "Player was squashed by a falling anvil." However if a player is merely touched by an anvil entity, or falling anvil, no damage will result until the falling anvil becomes a solid anvil-block in the airspace where the player is located. Falling anvils can be manipulated by TNT cannons, and will pass right through a mob or player, and will not damage them. In addition, if the player jumps at the correct time, the player will not be in the airspace where the anvil is, negating player damage; however, this is extremely difficult.

Trivia

 * If a block is renamed it will not keep its name after being placed.
 * It takes a total of 31 iron ingots to craft an anvil; more than a whole set of iron armor (24 ingots).
 * The falling ability of the anvil is a reference to the common cartoon trope.
 * The anvil has the same blast resistance as obsidian and the enchantment table.
 * If you rename a material, such as diamonds, it will not stack with unnamed or differently-named items.
 * An anvil will last about 25 uses on average.
 * Armor reduces the amount of damage caused by falling anvils.
 * The high blast resistance and transparency of the block makes for a good blast-proof window.
 * If a falling anvil lands on a pressure plate, it will damage any mob standing on the pressure plate, and drop as an item.
 * For unenchanted items, "unit repair" can easily cost more material than just crafting a new item or combining damaged items. The exception is armor, where you can use less material at the cost of experience levels.
 * If placed on top of exploding TNT blocks, the explosion won't affect the surrounding area.
 * This is because the Anvil falls into the space the TNT entity is occupying, and since the TNT's explosion power is not high enough to destroy the anvil, no blocks are destroyed.
 * Anvils are also commonly used as a guillotine because of its ability to kill mobs/players as a controlled entity.
 * No action sounds are given while stepping on or jumping on an anvil.
 * If an anvil is placed on top of a chest, you are still able to open the chest.
 * If two anvils are placed in a corner fashion like so |_ (the lines are the anvils) you are able to walk through the anvils if you are at the right angle.
 * Renaming a mob spawn egg "Dinnerbone" or "Grumm" will cause the mob to spawn upside-down.
 * Renaming a sheep spawn egg "jeb_" will cause the sheep to periodically change colors, however when sheared the sheep drops the color of wool it originally was.
 * Although anvils are made of iron, which requires a stone pickaxe to break, anvils only require a wooden pickaxe to be broken.
 * If an anvil falls on top of any kind of rail, torches, redstone, repeaters... the block will be replaced by the anvil and will not drop itself.
 * Depending on which of the 2 slots an item is placed in, the level amount for combining enchantments can differ. For example if you put a power 3 bow in slot 1 and Unbreaking 3 in slot 2 it may cost 8 levels. If they are reversed it may cost only 5 levels.
 * In villages, Blacksmiths still have double stone slabs instead of anvils even-though the stone slabs were replacements for an anvil.
 * Judging by the weight of iron and the volume of an anvil, an anvil from Minecraft in real life would weigh 6312 pounds, or 3.16 tons.