Our group was talking about fiddling with the attunement rules, so I finally broke down and did a quick-and-dirty analysis of the magic items in the DMG:
- 329 total magic items (includes splitting out the +1/+2/+3 versions of items)
- 50 are consumable, leaving 279 permanent items
- 167 of those 279 require attunement, or 60%
• 37 of 79 are uncommon, or 47%
• 57 of 95 are rare, or 60%
• 41 of 62 are very rare, or 66%
• 32 of 42 are legendary, or 76%
As expected, the more powerful an item, the more likely it requires attunement.
- Of those 167 that require attunement, they are split into the following categories
• 7 of 16 armor
• 19 of 22 rings
• 9 of 11 rods
• 4 of 8 shields
• 13 of 13 staves
• 12 of 15 wands
• 23 of 36 weapons
• 80 of 164 wonderous
• Items usable only by spellcasters have a higher percentage of attunable items (rods/staves/wands = 34 of 39 or 87% vs weapons/armor = 34 of 60 or 57%)
• Wonderous items, most of which are usable by any class, come in at 49%
- The most common boosts in attunable items (not including the complicated and obvious ones, like Holy Avenger, Robe of the Archmagi, etc):
• Provides ability bonus or high static ability (e.g., Amulet of Health, Ioun stone, Belt of Giant Strength, etc)
• Allows casting (by any class) of one or more spells or abilities that mirror spells (e.g., Ring of Invisibility, Eyes of Charming, Boots of Levitation, etc)
• Provides spellcaster with ability to cast spells without expending spell slots or extra spell slots (e.g., Staff of Power, Crystal Ball, Wand of Fireballs, and Ring of Spell Storing, Pearl of Power, Tome of the Stilled Tongue, etc)
• Provides damage resistance or immunity to any class (e.g., Ring of Warmth, Frost Brand, Brooch of Shielding, etc)
• Armor that provides damage resistance or immunity (e.g., Dragonscale armor, Armor of Resistance)
• Allows use of an item without requiring proficiency (e.g., Animated Shield, Dancing Sword, etc)
• Provides movement bonus or alternate move mode (e.g., Boots of Speed, Cloak of Arachnida, Ring of Free action, etc)
• Extra bonus to AC without regard to class, or disadvantage on being attacked (e.g., Ring of Protection, Cloak of Displacement, Ioun Stone, etc)
• Bonus to saving throws without regard to class (e.g., Mantle of Spell Resistance, Necklace of Adaptation, Ring of Spell Turning)
• Does extra damage without requiring a precondition (e.g., Vorpal Weapon, Bracers of Archery, Oathbow, etc)
• Provides Advantage specifically on Stealth or Perception checks, or Initiative (e.g., Cloak of the Bat, Eyes of the Eagle, Weapon of Warning, etc)
So if an item provides a non class-specific boost (like extra damage, bonus to saving throw, ability increase, damage resistance, move bonus, AC bonus, Advantage on Stealth/Perception), it should require attunement. If an item provides a spellcaster with the ability to cast spells without spell slots, it should require attunement. Armor that provides damage resistance requires attunement.
- Items that don’t require attunement follow these guidelines:
o Weapons have specific requirements (Giant or Dragon Slayer, Vicious Weapon, Mace of Smiting, etc)
o Armor has no extra combat effect (Dwarven Plate, Elven Chain, etc)
o Rods and Wands are usable by any class (Immovable Rod, Wand of Magic Detection, etc)
o Wonderous items are utilitarian and without combat effect, disappear after use, or are usable by any class (Bag of Holding, Deck of Many Things, Manuals, Carpet of Flying, Boots of Elvenkind)