Last Updated on January 22, 2023
New players just getting the hang of DnD often find themselves confused by DnD’s spell casting mechanics. I know I was.
Sometimes called a “Vancian magic system”, DnD limits the use of magic by spell casters with its famous “spell slot” mechanic.
The term “Vancian magic” comes from the magic system of science-fiction and fantasy author Jack Vance. Vancian magic has a few distinct hallmarks.
Spells are always discrete effects that do just what they say in the spell description and no more or no less. You can’t fine-tune a spell that throws a fireball to instead create a ray, for example.
Spells also require some level of preparation. After spells have been prepared, they can be cast a limited number of times. Once a magic-user is out of spells, they can’t do any more magic until they reprepare.
Magic users are therefore like a gun; they must be loaded with ammunition ahead of time, the kind of effects they can have are limited to the kinds of ammunition they are loaded with, and once they’re out of ammo there’s no more magic to be had.
This kind of magic system has formed the basis of DnD magic since the 1st edition, and its basic approach is still present in DnD 5e.
DnD 5e spell slots represent the limited number of discrete spells a magic-user can use. This sounds simple, but different magic-using classes have a variety of approaches to spell slots, and DnD has several peculiarities that are important to truly mastering the use of magic.
This system can be unintuitive for the uninitiated.
If you’re confused by spell slots, or are looking for a good way to explain them to those who are confused, this guide will present a clear explanation of how spell slots work across the many spellcasting classes of DnD 5e, including multiclassing, and provide some advice on how to use spell casting tactically in your game so that you never waste a spell.
How Spell Slots Work
If you play a magic-user in DnD 5e then as one of your class abilities you will receive some number of spell slots. Spell slots will be of a certain kind (level 1-9), and a certain number, and these will be determined by your class. Your character will use spell slots to cast spells.
The basic rules PDF from Wizard’s website provides a brief explanation:
“Regardless of how many spells a caster knows or prepares, he or she can cast only a limited number of spells before resting. Manipulating the fabric of magic and channeling its energy into even a simple spell is physically and mentally taxing, and higher-level spells are even more so.
Thus, each spellcasting class’s description includes a table showing how many spell slots of each spell level a character can use at each character level. For example, the 3rd-level wizard Umara has four 1st-level spell slots and two 2nd-level slots.
When a character casts a spell, he or she expends a slot of that spell’s level or higher, effectively “filling” a slot with the spell. You can think of a spell slot as a groove of a certain size—small for a 1st-level slot, larger for a spell of higher level.
A 1st-level spell fits into a slot of any size, but a 9th-level spell fits only in a 9th-level slot. So when Umara casts magic missile, a 1st-level spell, she spends one of her four 1st-level slots and has three remaining.
To put all this more simply, you need a spell slot of X level to cast a spell of X level. If thinking of it as a groove helps, then go for it.
For me, the analogy never helped as much as just thinking of spell slots as an additional component necessary for casting a spell, just like a verbal or somatic component.
If you want to cast the 1st level spell Charm Person then you’ll need to be able to perform its verbal and somatic components and have access to a 1st level spell slot.
When you expend a spell slot for any reason you can no longer use it until you recover it (usually after a long rest).
It’s important to note that when the rules talk about the levels of spells or spell slots that these are unconnected from character levels. Spell slots can only be between level 1 and 9, and a 5th level character won’t have 5th level spell slots.
When talking about spell and spell slots levels are often referred to. A spell slot, or spell,
Spells at Higher Levels
While you can’t cast a spell with a spell slot of a level lower than the spell, you can cast one with a spell slot of a higher level. The basic rules provide some info about this as well:
When a spellcaster casts a spell using a slot that is of a higher level than the spell, the spell assumes the higher level for that casting. For instance, if Umara casts magic missile using one of her 2nd-level slots, that magic missile is 2nd level. Effectively, the spell expands to fill the slot it is put into. Some spells, such as magic missile and cure wounds, have more powerful effects when cast at a higher level, as detailed in a spell’s description.”
Essentially, your higher-level spell slots can be used to cast any spell of a level equal or lower than their level. Thus, your 3rd level spell slot will be more versatile than your 2nd, and when you reach higher levels, your 9th level spell slot can be used to cast any spell you know.
In addition to cantrips and certain special abilities like racial feats or Warlock invocations, there exists a third way to cast spells without having to expend a spell slot.
Some spells have the ritual tag, which will be noted in their spell description. These spells can be cast without expending a spell slot if your class (Bard, Cleric, Druid, Sorcerer, and Wizard) can cast ritual spells or if you have taken the Ritual Caster feat.
Any spells cast using ritual casting have 10 minutes added to their casting time and cannot be cast at a higher level.
You can still cast a spell with the ritual tag with a spell slot, as normal.
Recovering Spell Slots
With a limited number of spell slots you may be anxious to know how to recover your spell slots once you use them up. According to the basic rules,
“Finishing a long rest restores any expended spell slots (see chapter 8 for the rules on resting). Some characters and monsters have special abilities that let them cast spells without using spell slots.”
A long rest is 8 hours.
Additionally, if you are a Wizard you have a class feature called Arcane Recovery. This lets you recover a number of spell slots on a short rest, as long as those spell slots have a combined level that is equal to or less than half your Wizard level rounded up, and as long as none of those spell slots are of 6th level or higher.
If you are a Sorcerer, you can create additional spell slots through the use of Sorcery points. These spell slots can’t be higher than 6th level. The following chart shows the cost of each spell slot.
|Level of Spell Slot||Number of Sorcery Points Required|
Lastly, as a Warlock you can recover all your spell slots on a short rest in addition to a long rest, though you will have fewer spell slots than other classes.
Spell Slots and Multiclassing
If you decide to multiclass this can make figuring out how many spell slots you have rather complicated. A single class, or multiclassing into a class without magic (like the Barbarian), means that to figure out how many spell slots you have you need only consult your class table.
If you multiclass however you must figure out your effective caster level and consult a chart (included below), to determine how many spell slots you have.
To calculate your effective caster level, add up all the levels you have in Bard, Cleric, Druid, Sorcerer, and Wizard classes.
Then add half of the levels (rounded down) you have in Artificer, Paladin, and Ranger. Lastly, add one third of the levels (rounded down) you have in the Eldritch Knight Fighter subclass and the Arcane Trickster Rogue subclass.
Therefore a 5th level Wizard, 5th level Cleric, 4th level Paladin, and 3rd level Eldritch Knight Fighter would have an effective caster level of 13, despite being a 17th level character.
Because of the way effective caster level is calculated the classes above are known as full casters, half casters, and one-third casters respectively.
While multiclassing can sometimes give you higher level spell slots than the level of spells you know, this does not confer an advantage.
If you have a 5th level spell slot, but because you have multiclassed and do not know any 5th level spells, you can only use that spell slot to cast the lower level spells you do know.
In addition, the spells you can learn are always calculated assuming that you are single classed. A 10th level character that only has 5 levels in Wizard can only know spells that 5th level Wizard who is single classed (and therefore a 5th level character) would know.
You therefore cannot use access to higher-level spell slots to gain access to higher-level spells for a particular class before you normally could.
How to Use Spell Slots Tactically
With a limited number of spell slots, it’s important to make every spell count.
At lower levels, you’ll often be faced with decisions.
Should you cast Sleep on the remaining goblins or save it for later in the dungeon?
Can Fireball rescue you from this surprise room full of mimics, or could you solve the problem with a lower-level spell slot?
Using your spells tactically will depend on a lot of factors, from your DM, to the plot of your campaign. Therefore, this guide cannot tell you what the best choice is.
But I can offer some general advice.
- If you can use a spell to solve a problem, do it. It might cost a whole slot but if you can neutralize an encounter or bypass a puzzle you will be able to save your party resources that they can use later when you’re running low on spell slots.
- Try to use the lowest level spell slot you need to. Casting Fireball with a 5th level spell slot can be fun, but a 5th level Fireball only does 2d6 more damage than at 3rd level. Choosing to do an average of 7 less damage is almost always better than losing a 5th level spell slot.
- Certain spell levels are much more powerful than they normally would be. The difference in power between 2nd and 3rd level spells and 5th and 6th level spells is much greater than the difference in power between 1st and 2nd level spells and 4th and 5th level spells. 6th level spells (and higher) are particularly powerful. This is reflected in the game by the inability of Arcane Recovery or the Sorcerer’s spell points from granting the character extra 6th level spell slots per day. Essentially this means that spell slots of those levels are more valuable than others, and it is especially wise to only use 6th level spell slots and higher to cast 6th level (and above) spells. Don’t use your 9th level spell slot to cast Fireball, for example.
- Lastly, don’t hoard your spell slots. While it may seem tempting to save them until the perfect moment, that moment won’t come if you get knocked out or your entire party goes down. If it’ll save you or give you an edge in a risky fight, use the spell slot even if it’s an inefficient use of the spell. Cast Shield as many times as you need to to keep yourself alive, your party will thank you when you’re still alive to Counterspell a Slow later.
Common Questions About Spell Slots In 5e
Spell slots can be complicated and trying to figure out how many spell slots you have as a multiclassed character can get downright messy. But spell slots are a vital part of DnD.
Without a way to limit the number of spells a user can cast in a day Wizards and other full casters would become wildly more powerful than any other class.
With an unlimited number of Fireballs to throw at enemies it would hardly be worth playing anything else!
Spell slots have been around since the beginning of DnD and they are baked into the core mechanics of the system.
Whether you’re just trying to figure out the basic rules or you’re trying to make the best use out of your single 6th level spell slot, understanding DnD’s take on the Vancian magic system will be integral to your spell-slinging adventures.
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Growing up I spent most of my time reading, so when I first started playing RPGs in middle school and got a copy of DnD 3.5’s rules I loved their collaborative take on storytelling. These days I like to use RPGs to develop my creative problem-solving skills as well.