System Reference Document 5.2.1
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castinG in arMor
You must have training with any armor you are wear -
ing to cast spells while wearing it. You are otherwise 
too hampered by the armor for spellcasting.
Spells
Gaining Spells
Before you can cast a spell, you must have the spell 
prepared in your mind or have access to the spell 
from a magic item, such as a Spell Scroll . Your fea-
tures specify which spells you have access to, if any; 
whether you always have certain spells prepared; 
and whether you can change the list of spells you 
have prepared.
Preparing Spells
If you have a list of level 1+ spells you prepare, your 
spellcasting feature specifies when you can change 
the list and the number of spells you can change, as 
summarized in the Spell Preparation by Class table.
Spell Preparation by Class
Class Change When You 
…
Number of Spells
Bard Gain a level One
Cleric Finish a Long Rest Any
Druid Finish a Long Rest Any
Paladin Finish a Long Rest One
Ranger Finish a Long Rest One
Sorcerer Gain a level One
Warlock Gain a level One
Wizard Finish a Long Rest Any
Most spellcasting monsters don’t change their lists 
of prepared spells, but the GM is free to alter them.
Always-Prepared Spells
Certain features might give you a spell that you 
always have prepared. If you also have a list of pre -
pared spells that you can change, a spell that you 
always have prepared doesn’t count against the 
number of spells on that list.
Casting Spells
Each spell description has a series of entries that 
provide the details needed to cast the spell. The fol -
lowing sections explain each of those entries, which 
follow a spell’s name.
Spell Level
Every spell has a level from 0 to 9, which is indi -
cated in a spell’s description. A spell’s level is an 
indicator of how powerful it is. Cantrips—simple 
spells that can be cast almost by rote—are level 0. 
The rules for each spellcasting class say when its 
members gain access to spells of certain levels.
Spell Slots
Spellcasting is taxing, so a spellcaster can cast only 
a limited number of level 1+ spells before resting. 
Spell slots are the main way a spellcaster’s magical 
potential is represented. Each spellcasting class 
gives its members a limited number of spell slots of 
certain spell levels. For example, a level 3 Wizard 
has four level 1 spell slots and two level 2 slots.
 When you cast a spell, you expend a slot of that 
spell’s level or higher, effectively “filling” a slot with 
the spell. Imagine a spell slot is a groove of a certain 
size—small for a level 1 slot and larger for a high -
er-level spell. A level 1 spell fits into a slot of any 
size, but a level 2 spell fits only into a slot that’s at 
least level 2. So when a level 3 Wizard casts Magic 
Missile, a level 1 spell, that Wizard spends one of 
four level 1 slots and has three remaining.
 Finishing a Long Rest restores any expended spell 
slots.
Casting without Slots
There are several ways to cast a spell without 
expending a spell slot:
Cantrips.  A cantrip is cast without a spell slot.
Rituals . Certain spells have the Ritual tag in the 
Casting Time entry. Such a spell can be cast fol -
lowing the normal rules for spellcasting, or it can 
be cast as a Ritual. The Ritual version of a spell 
takes 10 minutes longer to cast than normal, but it 
doesn’t expend a spell slot. To cast a spell as a Rit -
ual, a spellcaster must have it prepared.
Special Abilities. Some characters and monsters 
have special abilities that allow them to cast spe -
cific spells without a spell slot. This casting is usu -
ally limited in another way, such as being able to 
cast the spell a limited number of times per day.
Magic Items.  Spell Scrolls and some other magic 
items contain spells that can be cast without a 
spell slot. The description of such an item speci -
fies how many times a spell can be cast from it.
Using a Higher-Level Spell Slot
When a spellcaster casts a spell using a slot that is 
of a higher level than the spell, the spell takes on 
the higher level for that casting. For instance, if a 
Wizard casts Magic Missile  using a level 2 slot, that 
Magic Missile is level 2. Effectively, the spell expands 
to fill the slot it is put into.