diff --git a/index.js b/index.js
index e91fb33..d214f62 100644
--- a/index.js
+++ b/index.js
@@ -95,6 +95,52 @@ function provider (registry, { Biome, version }) {
     return 0
   }
 
+  // Block tags (registry.tags, minecraft-data 1.13+) describe which tools mine a block since 1.17. When present they
+  // replace the single-material speed lookup: a block can be in several mineable/* tags, and the sword and shears
+  // rules below are the vanilla ToolMaterial/ShearsItem constants, which are not in any data file.
+  const blockTags = registry.tags?.['minecraft:block']
+  const tagSets = {}
+  function inTag (tag, blockName) {
+    if (!tagSets[tag]) tagSets[tag] = new Set(blockTags?.[`minecraft:${tag}`] ?? [])
+    return tagSets[tag].has(`minecraft:${blockName}`)
+  }
+  const hasToolTags = Boolean(blockTags?.['minecraft:mineable/pickaxe'])
+  const TOOL_TYPES = ['pickaxe', 'axe', 'shovel', 'hoe']
+
+  function tagBreakingSpeed (block, heldItemType) {
+    const item = registry.items[heldItemType]
+    if (!item) return 1
+    const name = block.name
+    if (item.name === 'shears') {
+      if (name === 'cobweb' || inTag('leaves', name)) return 15
+      if (inTag('wool', name)) return 5
+      if (name === 'vine' || name === 'glow_lichen') return 2
+      return 1
+    }
+    if (item.name.endsWith('_sword')) {
+      if (name === 'cobweb') return 15
+      // bamboo breaks instantly with a sword: BambooStalkBlock/BambooSaplingBlock.getDestroyProgress up to 1.21.4, the
+      // sword_instantly_mines tag from 1.21.5
+      const instantly = blockTags['minecraft:sword_instantly_mines'] ? inTag('sword_instantly_mines', name) : (name === 'bamboo' || name === 'bamboo_sapling')
+      if (instantly) return Infinity
+      // 1.20+: SwordItem.getDestroySpeed is 1.5 for the sword_efficient tag.
+      if (blockTags['minecraft:sword_efficient']) return inTag('sword_efficient', name) ? 1.5 : 1
+      // 1.17 to 1.19 have no sword_efficient tag: getDestroySpeed returns 1.5 for the leaves tag and the PLANT,
+      // REPLACEABLE_PLANT, VEGETABLE (gourd) and VINE materials, 1 otherwise. These are ToolMaterial constants, so
+      // encode them here rather than trusting the material table, whose composite sword speeds do not survive
+      // regeneration (e.g. leaves' sword speed drops from 1.5 to 1 when the tags are rebuilt).
+      if (inTag('leaves', name)) return 1.5
+      const materials = (block.material ?? '').split(';')
+      if (materials.some(m => m === 'plant' || m === 'gourd' || m === 'vine_or_glow_lichen')) return 1.5
+      return 1
+    }
+    for (const type of TOOL_TYPES) {
+      const speed = registry.materials[`mineable/${type}`]?.[heldItemType]
+      if (speed && inTag(`mineable/${type}`, name)) return speed
+    }
+    return 1
+  }
+
   function getMiningFatigueMultiplier (effectLevel) {
     switch (effectLevel) {
       case 0: return 1.0
@@ -306,14 +352,17 @@ function provider (registry, { Biome, version }) {
     digTime (heldItemType, creative, inWater, notOnGround, enchantments = [], effects = {}) {
       if (creative) return 0
 
-      const materialToolMultipliers = registry.materials[this.material]
-      const isBestTool = heldItemType && materialToolMultipliers && materialToolMultipliers[heldItemType]
-
       // Compute breaking speed multiplier
       let blockBreakingSpeed = 1
 
-      if (isBestTool) {
-        blockBreakingSpeed = materialToolMultipliers[heldItemType]
+      if (heldItemType && hasToolTags) {
+        blockBreakingSpeed = tagBreakingSpeed(this, heldItemType)
+        if (blockBreakingSpeed === Infinity) return 0
+      } else {
+        const materialToolMultipliers = registry.materials[this.material]
+        if (heldItemType && materialToolMultipliers && materialToolMultipliers[heldItemType]) {
+          blockBreakingSpeed = materialToolMultipliers[heldItemType]
+        }
       }
 
       // Efficiency is applied if tools speed multiplier is more than 1.0
diff --git a/test/basic.test.js b/test/basic.test.js
index 8c16554..13d805a 100644
--- a/test/basic.test.js
+++ b/test/basic.test.js
@@ -2,6 +2,92 @@
 
 const expect = require('expect').default
 
+// Block tags decide which tools mine a block from 1.17 on (minecraft-data tags.json, exposed as registry.tags).
+// The fixture is the subset of vanilla 26.1 tags these cases need, in the tags.json shape.
+describe('Dig time from block tags', () => {
+  const registry = require('prismarine-registry')('26.1')
+  registry.tags = {
+    'minecraft:block': {
+      'minecraft:leaves': ['minecraft:oak_leaves'],
+      'minecraft:mineable/axe': ['minecraft:melon', 'minecraft:oak_log'],
+      'minecraft:mineable/hoe': ['minecraft:oak_leaves'],
+      'minecraft:mineable/pickaxe': ['minecraft:iron_ore', 'minecraft:obsidian', 'minecraft:stone'],
+      'minecraft:sword_efficient': ['minecraft:melon'],
+      'minecraft:sword_instantly_mines': ['minecraft:bamboo'],
+      'minecraft:wool': ['minecraft:white_wool']
+    }
+  }
+  const Block = require('prismarine-block')(registry)
+  const block = name => Block.fromStateId(registry.blocksByName[name].defaultState, 0)
+  const item = name => registry.itemsByName[name].id
+  const dig = (blockName, itemName, enchantments = []) => block(blockName).digTime(itemName ? item(itemName) : null, false, false, false, enchantments)
+
+  it('uses the pickaxe tier speed for a tier-gated ore', () => {
+    expect(dig('iron_ore', 'diamond_pickaxe')).toBe(600)
+    expect(dig('obsidian', 'diamond_pickaxe')).toBe(9400)
+  })
+  it('applies efficiency on top of the tag speed', () => {
+    expect(dig('iron_ore', 'diamond_pickaxe', [{ name: 'efficiency', lvl: 5 }])).toBe(150)
+  })
+  it('keeps the harvest penalty for a tool below the required tier', () => {
+    expect(dig('iron_ore', 'wooden_pickaxe')).toBe(7500)
+    expect(dig('stone', null)).toBe(7500)
+  })
+  it('uses the vanilla sword rules', () => {
+    expect(dig('melon', 'diamond_sword')).toBe(1000)
+    expect(dig('melon', 'diamond_axe')).toBe(200)
+    expect(dig('bamboo', 'diamond_sword')).toBe(0)
+  })
+  it('uses the vanilla shears rules', () => {
+    expect(dig('oak_leaves', 'shears')).toBe(0)
+    expect(dig('white_wool', 'shears')).toBe(250)
+  })
+  it('ignores tools that do not apply to the block', () => {
+    expect(dig('oak_log', 'diamond_pickaxe')).toBe(dig('oak_log', null))
+  })
+})
+
+describe('Dig time from block tags before the sword tags (1.17 to 1.19)', () => {
+  const registry = require('prismarine-registry')('1.19.4')
+  registry.tags = {
+    'minecraft:block': {
+      'minecraft:leaves': ['minecraft:oak_leaves'],
+      'minecraft:mineable/axe': ['minecraft:bamboo', 'minecraft:melon'],
+      'minecraft:mineable/hoe': ['minecraft:oak_leaves'],
+      'minecraft:mineable/pickaxe': ['minecraft:stone']
+    }
+  }
+  const Block = require('prismarine-block')(registry)
+  const block = name => Block.fromStateId(registry.blocksByName[name].defaultState, 0)
+  const dig = (blockName, itemName) => block(blockName).digTime(registry.itemsByName[itemName].id, false, false, false)
+
+  it('applies the pre-1.20 sword rule from the leaves tag and plant materials', () => {
+    // SwordItem.getDestroySpeed is 1.5 for the leaves tag and the PLANT/VEGETABLE/VINE materials. This comes from the
+    // tag and material names, not the material table's composite sword speeds, which drop to 1 when tags are regenerated.
+    expect(dig('oak_leaves', 'diamond_sword')).toBe(200) // leaves tag -> 1.5
+    expect(dig('melon', 'diamond_sword')).toBe(1000) // gourd (VEGETABLE) material -> 1.5
+    expect(dig('vine', 'diamond_sword')).toBe(200) // vine material -> 1.5
+    expect(dig('stone', 'diamond_sword')).toBe(7500) // no sword rule -> 1
+  })
+  it('mines bamboo instantly with a sword', () => {
+    expect(dig('bamboo', 'diamond_sword')).toBe(0)
+    expect(dig('bamboo', 'diamond_axe')).toBe(200)
+  })
+  it('still takes the tool tiers from the mineable tags', () => {
+    expect(dig('oak_leaves', 'diamond_hoe')).toBe(0)
+    expect(dig('stone', 'diamond_pickaxe')).toBe(300)
+  })
+})
+
+describe('Dig time without block tags (before 1.17)', () => {
+  const registry = require('prismarine-registry')('1.16.4')
+  const Block = require('prismarine-block')(registry)
+  it('mines stone with an iron pickaxe from materials', () => {
+    const stone = Block.fromStateId(registry.blocksByName.stone.defaultState, 0)
+    expect(stone.digTime(registry.itemsByName.iron_pickaxe.id, false, false, false)).toBe(400)
+  })
+})
+
 // https://minecraft.gamepedia.com/Breaking#Blocks_by_hardness
 describe('Dig time', () => {
   describe('1.20.5', () => {