Enchanting table mechanics

This article is about the mechanics of enchanting with enchanting tables.

Nearby bookshelves raise the experience cost, which increases the value of the offered enchantments. The maximum number of active bookshelves is 15, and further bookshelves are ignored.

In order to have an effect, the bookshelves must be placed exactly two blocks from the enchanting table along one horizontal axis, up to two blocks along the other, and on the same height as the table or one block higher. Additionally, the bookshelf must not be blocked, the exact definition of which differs between the Java and Bedrock editions.

The 2-high space between the bookshelf and table must be air (even a torch, snow cover or carpet blocks the effect), where "between" is as shown in the following diagrams (the blank spaces are air, and the do not matter):

Like this from the top:		or
and like this from the side:		or

The space between the bookshelf and table at the height of the bookshelf must be a block in the tag #enchantment_power_transmitter like air, snow and short grass. For corner bookshelves, the space between is 1 block diagonal from the enchanting table; for all other bookshelves, the gap must be to the side of the enchanting table. This is illustrated in the following diagrams (the blank spaces are air, and the do not matter):

Like this from the top:		or
and like this from the side:		or

The glyph particles, which fly from bookshelves, follow different rules and may appear even if the bookshelves are not enhancing the table.

There are many possible bookshelf arrangements that can reach the enchantment limit. A simple method is to surround the enchanting table with a 1-block high square of bookshelves with an empty space anywhere on the perimeter:

Another alternative that is now available is to build a 'library corner' where each bookshelf is two blocks high, as in the plan below. This arrangement gives space for 16 shelves, which is one more than needed, so if the corner bookshelf column cannot be seen, removing one of the two bookshelves in that does not have any effect, either technically or visually.

With a data pack, it's possible to replace the bookshelf with a block in the tag #enchantment_power_provider.

For an item to be enchantable, it must fulfill these conditions:

• It is enchantable, meaning in Java Edition it has the components enchantable and enchantments.​^{[more information needed]}
• It has no enchantments, meaning in Java Edition the component enchantments must be empty.​^{[more information needed]}

If the item meets the conditions but has no available enchantments, it will be possible to select the slot at the enchanting table, but nothing will happen.

When an item is placed in an enchanting table, the experience cost of each enchantment slot is selected depending on the slot and the number of nearby bookshelves, which is capped at 15.

For each slot, a base experience cost is calculated as:

${\displaystyle xpBase\leftarrow 1+\text{randInt}\left(7\right)+\lfloor \frac{\min (15,bookshelves)}{2}\rfloor +\text{randInt}(\min (15,bookshelves))}$

where ${\displaystyle \text{randInt}}$ generates a random integer in range ${\displaystyle 0}$ to ${\displaystyle n}$ (both included).

The final experience cost is then calculated depending on the slot:

Top slot: ${\displaystyle xpCost\leftarrow \lfloor \max (1,\frac{xpBase}{3})\rfloor }$

Middle slot: ${\displaystyle xpCost\leftarrow \lfloor \frac{2\cdot xpBase}{3}\rfloor +1}$

Bottom slot: ${\displaystyle xpCost\leftarrow \lfloor \max (xpBase,2\cdot bookshelves)\rfloor }$

Bookshelves	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
Experience cost of top slot	1–2	1–3	1–3	1–4	1–4	1–5	1–5	1–6	1–6	1–7	2–7	2–8	2–8	2–9	2–9	2–10
Experience cost of middle slot	1–6	1–7	2–8	2–9	3–10	3–11	3–12	3–13	4–14	4–15	5–16	5–17	5–18	5–19	6–20	6–21
Experience cost of bottom slot	1–8	2–9	4–11	6–12	8–14	10–15	12–17	14–18	16–20	18–21	20–23	22–24	24–26	26–27	28–29	30

This section describes how enchantments for an item are selected for a given experience cost.

This process is used by various mechanics:

• When enchanting with an enchanting table.
• In Java Edition when generating items with the item modifier enchant_with_levels, which is used in villager trade definitions for traded equipments and loot tables for generated loot and fishing.
• In Bedrock Edition when generating traded equipments, generated loot, and fishing.
• In Java Edition when generating items with the enchantment providers enchantments_by_cost or enchantments_by_cost_with_difficulty, which is used for gearing mobs.
• In Bedrock Edition when gearing mobs.

For each slot, the enchantment cost, which is not shown in game, is calculated depending on the item's enchantability and the experience cost:

${\displaystyle eCost\leftarrow \text{round}((xpCost+1+\text{randInt}\left(\lfloor \frac{enchantability}{4}\rfloor \right)+\text{randInt}\left(\lfloor \frac{enchantability}{4}\rfloor \right))\cdot (1+\text{randTri}\left(0.15\right)))}$

where ${\displaystyle \text{randInt}\left(n\right)}$ generates a random integer in range ${\displaystyle 0}$ to ${\displaystyle n}$ (both included)

and ${\displaystyle \text{randTri}\left(n\right)}$ generates a random number in range ${\displaystyle -n}$ (included) to ${\displaystyle n}$ (excluded) with triangular distribution:

${\displaystyle \text{randTri}\left(n\right)\mapsto (\text{randFloat}\left(\right)+\text{randFloat}\left(\right)-1)\cdot n}$

where ${\displaystyle \text{randFloat}\left(\right)}$ generates a random number in range ${\displaystyle 0}$ (included) to ${\displaystyle 1}$ (excluded).

In Java Edition, an item's enchantability is stored in the minecraft:enchantable item component.

Item	Enchantability	${\displaystyle \lfloor \frac{enchantability}{4}\rfloor }$
Golden Armor	25	6
Golden Weapons and Tools	22	5
Leather Armor Mace Netherite Armor Netherite Weapons and Tools Wooden Weapons and Tools	15	3
Iron Weapons and Tools	14	3
Copper Weapons and Tools	13	3
Chainmail Armor	12	3
Diamond Armor Diamond Weapons and Tools	10	2
Iron Armor Turtle Shell	9	2
Copper Armor	8	2
Stone Weapons and Tools	5	1
All other enchantable items Book Bow Crossbow Fishing Rod Trident	1	0

In Java Edition, the initial candidates are:

• the enchanting table's list of enchantments are stored in the tag #in_enchanting_table.

• the item modifier enchant_with_levels can overwrite that list of enchantments with its field options, which default is used by the tags #on_random_loot, and #on_traded_equipment.

• enchantment providers use the field enchantments, which default to the tag #on_mob_spawn_equipment.

In vanilla, this means that all non-treasure enchantments are initially candidates, and that for generated loot and fishing, Curse of Binding, Curse of Vanishing, Frost Walker, and Mending are also initial candidates.

If the item to enchant is not a book, all enchantments to which the item is not a primary item are removed.

Finally, the level for each enchantment is determined. The enchantment's highest level for which the enchantment cost falls within its cost range is the candidate, and if the cost is not within any of its ranges, the enchantment is removed.

In Java Edition, enchantments, including which other enchantments they're exclusive with, what items are primary to them, and the cost ranges of their levels are defined in enchantment definition. Books being primary to all enchantments is hardcoded.

The selection uses repetition, in which it selects one of the candidate enchantments and has a chance to repeat and add additional enchantments. The change of the enchantment cost in this final stage does not retroactively change the set of candidate.

1. A random candidate is selected based on weights, meaning the chance of a candidate being selected is its weight divided by the total weight of the current candidates.
2. The selected candidate and incompatible ones are removed from the set of candidates, and if no candidates remain, the selection ends.
3. If a chance of ${\displaystyle \frac{eCost+1}{50}}$ is fails, the enchantment selection ends.
4. The enchantment cost (${\displaystyle eCost}$) is divided by two and rounded down, and the process returns to step 1.

Finally after the loop, if the item is a book, an enchanting table is used, and multiple enchantments were selected, a random one is removed.

If the item being enchanted is a book, it will be turned into an enchanted book and in Java Edition the enchantments are stored in the stored_enchantments component.

In Java Edition, for all other items, the enchantments are stored in the enchantments component.

The enchantments that enchanting tables offer are determined using the enchanting seed that is stored under XpSeed in each player's data. After enchanting an item, the player's seed is regenerated, resulting in different enchantments.

This means enchanting tables with the same number of nearby bookshelves will offer the same enchantments for all items with the same enchantability and the same possible enchantments (same item-type or one of pickaxes, shovels or hoes) until an item is enchanted.

When joining a world for the first time, the seed is initialized to 0, however when joining a world with an already present enchanting seed of 0, it will be regenerated.^[1]

This meaning leaving and rejoining a world for the first time gives new enchantments without enchanting an item, and the first enchantment before ever leaving a world will always give the same enchantment for the same item-bookshelves-combination, such as Looting III and Unbreaking III for a Netherite Sword with 15 bookshelves.

The given cost-ranges are the effective ranges.^[2]

Item	Enchantment	Compatibility	Weight	Level I cost	Level II cost	Level III cost	Level IV cost	Level V cost
Helmet	Aqua Affinity		2	1–41
	Respiration		2	10–19	20–29	30–60
	Thorns‌[BE only]		1	10–29	30–49	50–100
	Unbreaking		5	5–12	13–20	21–71
	Blast Protection	Incompatible with each other	2	5–12	13–20	21–28	29–37
	Fire Protection		5	10–17	18–25	26–33	34–42
	Projectile Protection		5	3–8	9–14	15–20	21–27
	Protection		10	5–12	13–20	21–28	29–37
Chestplate	Thorns		1	10–29	30–49	50–100
	Unbreaking		5	5–12	13–20	21–71
	Blast Protection	Incompatible with each other	2	5–12	13–20	21–28	29–37
	Fire Protection		5	10–17	18–25	26–33	34–42
	Projectile Protection		5	3–8	9–14	15–20	21–27
	Protection		10	5–12	13–20	21–28	29–37
Leggings	Thorns‌[BE only]		1	10–29	30–49	50–100
	Unbreaking		5	5–12	13–20	21–71
	Blast Protection	Incompatible with each other	2	5–12	13–20	21–28	29–37
	Fire Protection		5	10–17	18–25	26–33	34–42
	Projectile Protection		5	3–8	9–14	15–20	21–27
	Protection		10	5–12	13–20	21–28	29–37
Boots	Feather Falling		5	5–10	11–16	17–22	23–29
	Thorns‌[BE only]		1	10–29	30–49	50–100
	Unbreaking		5	5–12	13–20	21–71
	Blast Protection	Incompatible with each other	2	5–12	13–20	21–28	29–37
	Fire Protection		5	10–17	18–25	26–33	34–42
	Projectile Protection		5	3–8	9–14	15–20	21–27
	Protection		10	5–12	13–20	21–28	29–37
	Depth Strider	Incompatible with Frost Walker	2	10–19	20–29	30–45
Sword	Fire Aspect		2	10–19	20–80
	Knockback		5	5–24	25–75
	Looting		2	15–23	24–32	33–83
	Sweeping Edge‌[JE only]		2	5–13	14–22	23–38
	Unbreaking		5	5–12	13–20	21–71
	Bane of Arthropods	Incompatible with each other	5	5–12	13–20	21–28	29–36	37–57
	Sharpness		10	1–11	12–22	23–33	34–44	45–65
	Smite		5	5–12	13–20	21–28	29–36	37–57
Spear	Fire Aspect		2	10–19	20–80
	Knockback		5	5–24	25–75
	Looting		2	15–23	24–32	33–83
	Lunge		5	5–12	13–20	21–41
	Unbreaking		5	5–12	13–20	21–71
	Bane of Arthropods	Incompatible with each other	5	5–12	13–20	21–28	29–36	37–57
	Sharpness		10	1–11	12–22	23–33	34–44	45–65
	Smite		5	5–12	13–20	21–28	29–36	37–57
Axe	Cleaving‌[JE Combat Tests only]		2	5–24	25–44	45–65
	Efficiency		10	1–10	11–20	21–30	31–40	41–91
	Unbreaking		5	5–12	13–20	21–71
	Fortune	Incompatible with each other	2	15–23	24–32	33–83
	Silk Touch		1	15–65
	Bane of Arthropods‌[BE only]	Incompatible with each other	5	5–12	13–20	21–28	29–36	37–57
	Sharpness‌[BE only]		10	1–11	12–22	23–33	34–44	45–65
	Smite‌[BE only]		5	5–12	13–20	21–28	29–36	37–57
Pickaxe Shovel Hoe	Efficiency		10	1–10	11–20	21–30	31–40	41–91
	Unbreaking		5	5–12	13–20	21–71
	Fortune	Incompatible with each other	2	15–23	24–32	33–83
	Silk Touch		1	15–65
Bow	Flame		2	20–50
	Power		10	1–10	11–20	21–30	31–40	41–56
	Punch		2	12–31	32–57
	Unbreaking		5	5–12	13–20	21–71
	Infinity	Incompatible with Mending	1	20–50
Crossbow	Quick Charge		5	12–31	32–50
	Unbreaking		5	5–12	13–20	21–71
	Multishot	Incompatible with each other	2	20–50
	Piercing		10	1–10	11–20	21–30	31–50
Fishing Rod	Luck of the Sea		2	15–23	24–32	33–83
	Lure		2	15–23	24–32	33–83
	Unbreaking		5	5–12	13–20	21–71
Trident	Impaling		2	1–8	9–16	17–24	25–32	33–53
	Unbreaking		5	5–12	13–20	21–71
	Channeling	Incompatible with Riptide	1	25–50
	Loyalty		5	12–18	19–25	26–50
	Riptide	Incompatible with Channeling and Loyalty	2	17–23	24–30	31–50
Mace	Fire Aspect‌[BE only]		2	10–19	20–80
	Unbreaking		5	5–12	13–20	21–71
	Breach	Incompatible with each other	2	15–23	24–32	33–41	42–92
	Density		5	5–12	13–20	21–28	29–36	37–57
	Bane of Arthropods‌[BE only]		5	5–12	13–20	21–28	29–36	37–57
	Smite‌[BE only]		5	5–12	13–20	21–28	29–36	37–57
Book	Aqua Affinity		2	1–41
	Efficiency		10	1–10	11–20	21–30	31–40	41–91
	Feather Falling		5	5–10	11–16	17–22	23–29
	Fire Aspect		2	10–19	20–80
	Flame		2	20–50
	Impaling		2	1–8	9–16	17–24	25–32	33–53
	Knockback		5	5–24	25–75
	Looting		2	15–23	24–32	33–83
	Luck of the Sea		2	15–23	24–32	33–83
	Lunge		5	5–12	13–20	21–41
	Lure		2	15–23	24–32	33–83
	Power		10	1–10	11–20	21–30	31–40	41–56
	Punch		2	12–31	32–57
	Quick Charge		5	12–31	32–50
	Respiration		2	10–19	20–29	30–60
	Sweeping Edge‌[JE only]		2	5–13	14–22	23–38
	Thorns		1	10–29	30–49	50–100
	Unbreaking		5	5–12	13–20	21–71
	Bane of Arthropods	Incompatible with each other	5	5–12	13–20	21–28	29–36	37–57
	Breach		2	15–23	24–32	33–41	42–92
	Cleaving‌[JE Combat Tests only]		2	5–24	25–44	45–65
	Density		5	5–12	13–20	21–28	29–36	37–57
	Sharpness		10	1–11	12–22	23–33	34–44	45–65
	Smite		5	5–12	13–20	21–28	29–36	37–57
	Blast Protection	Incompatible with each other	2	5–12	13–20	21–28	29–37
	Fire Protection		5	10–17	18–25	26–33	34–42
	Projectile Protection		5	3–8	9–14	15–20	21–27
	Protection		10	5–12	13–20	21–28	29–37
	Channeling	Incompatible with Riptide	1	25–50
	Loyalty		5	12–18	19–25	26–50
	Riptide	Incompatible with Channeling and Loyalty	2	17–23	24–30	31–50
	Depth Strider	Incompatible with Frost Walker	2	10–19	20–29	30–45
	Fortune	Incompatible with each other	2	15–23	24–32	33–83
	Silk Touch		1	15–65
	Infinity	Incompatible with Mending	1	20–50
	Multishot	Incompatible with each other	2	20–50
	Piercing		10	1–10	11–20	21–30	31–50

Java Edition
1.18.2			22w07a				Bookshelf detection method changed. Previously, both the block at the level of the enchanting table and the layer above needed to be air, or the enchanting table was blocked. Additionally, bookshelves 2 across 1 over changed from being blocked by the corner block to being blocked by the edge block.

• https://github.com/SeeYou-Man/Minecraft-Enchantment-Probabilities – A GitHub project to simulate the probability to get specific enchantments in 1.21.
• https://web.archive.org/web/20181019012113/http://minecraftenchantmentcalculator.com/rev6/ (archived) – Tests enchantments by simulating probability of getting specific enchantments on a tool based on level and (optionally) the "clue" shown
• https://minecraft.tools/en/enchant.php – Provides some ability to test enchantments, although its interface is significantly less verbose on the specifics
• https://github.com/Earthcomputer/EnchantmentCracker – Cracks the XP seed and lets you choose the exact enchantments you want, though the process is highly tedious and error-prone. Deprecated in favor of clientcommands