Activating some magic items requires a user to do something special, such as holding the item and uttering a command word. The description of each item category or individual item details how an item is activated. Certain items use the following rules for their activation.
If an item requires an action to activate, that action isn’t a function of the Use an Object action, so a feature such as the rogue’s Fast Hands can’t be used to activate the item.
Command Word
It Must Be Spoken
A command word is a word or phrase that must be spoken for an item to work. A magic item that requires a command word can't be activated in an area where sound is prevented, as in the area of the silence spell.
Consumables
One-Time Magic Items
Some items are used up when they are activated. A potion or an elixir must be swallowed, or an oil applied to the body. The writing vanishes from a scroll when it is read. Once used, a consumable item loses its magic.
Spells
Casting from an item
Some magic items allow the user to cast a spell from the item. The spell is cast at the lowest possible spell and caster level, doesn't expend any of the user's spell slots, and requires no components, unless the item's description says otherwise.
Time and Concentration
The spell uses its normal casting time, range, and duration, and the user of the item must concentrate if the spell requires concentration.
Potions
Many items, such as potions, bypass the casting of a spell and confer the spell's effects, with their usual duration.
Exceptions
Certain items make exceptions to these rules, changing the casting time, duration, or other parts of a spell.
Some Require Your Spellcasting Ability
A magic item, such as certain staffs, may require you to use your own spellcasting ability when you cast a spell from the item.
Some Require Your Spellcasting Ability
A magic item, such as certain staffs, may require you to use your own spellcasting ability when you cast a spell from the item. If you have more than one spellcasting ability, you choose which one to use with the item. If you don't have a spellcasting ability -- perhaps you're a rogue with the Use Magic Device feature -- your spellcasting ability modifier is +0 for the item, and your proficiency bonus does apply.
Charges
Activating Properties
Some magic items have charges that must be expended to activate their properties.
Identify
The number of charges an item has remaining is revealed when an identify spell is cast on it, as well as when a creature attunes to it. Additionally, when an item regains charges, the creature attuned to it learns how many charges it regained.
