Secret Lesson 73

Casting Time, the Magic Action, Bonus Action Spells, Reaction Spells, Longer Casting Times, and Rituals

In Lessons 71 and 72, we answered two fundamental questions:

WHICH SPELLS CAN I CAST?

and:

WHAT RESOURCE POWERS THEM?

Now we answer the third:

WHEN CAN I CAST THEM?

This is the point where spellcasting connects directly to:

ACTION ECONOMY

A spell might require:

AN ACTION

A BONUS ACTION

A REACTION

1 MINUTE

10 MINUTES

1 HOUR

or even:

LONGER

The spell's:

CASTING TIME

tells you exactly what is required.

And SRD 5.2.1 introduces one particularly important restriction:

ON A TURN, YOU CAN EXPEND ONLY ONE SPELL SLOT TO CAST A SPELL

 

Understanding that rule correctly is essential.

It does not mean:

ONE SPELL PER TURN

It means:

ONE SPELL SLOT EXPENDED TO CAST A SPELL PER TURN

That difference changes everything.

PART ONE — WHAT IS CASTING TIME?

Every spell contains a:

CASTING TIME

entry.

That entry tells you:

HOW LONG CASTING THE SPELL TAKES

Most spells require:

THE MAGIC ACTION

But some require:

A BONUS ACTION

A REACTION

or:

ONE MINUTE OR MORE

 

EXAMPLES

Fire Bolt:

ACTION

Misty Step:

BONUS ACTION

Shield:

REACTION

Create Undead:

1 MINUTE

Control Weather:

10 MINUTES

 

These are:

DIFFERENT CASTING PROCEDURES

PART TWO — MOST SPELLS USE THE MAGIC ACTION

If a spell's Casting Time is:

ACTION

you cast it using:

THE MAGIC ACTION

The Rules Glossary defines the Magic action as the action used to:

CAST A SPELL WITH A CASTING TIME OF AN ACTION

or:

USE A FEATURE OR MAGIC ITEM THAT REQUIRES A MAGIC ACTION

 

IMPORTANT

The action is specifically called:

MAGIC

It is one of the game's named actions.

Other named actions include:

ATTACK

DASH

DODGE

HELP

HIDE

READY

SEARCH

STUDY

and:

UTILIZE

PART THREE — ACTION SPELL EXAMPLE

Fire Bolt is a Cantrip with:

CASTING TIME: ACTION

 

On your turn:

MAGIC ACTION

↓

CAST FIRE BOLT

You then resolve the spell's:

RANGE

COMPONENTS

TARGET

SPELL ATTACK

and:

DAMAGE

PART FOUR — MAGIC ACTION DOES NOT MEAN EVERY MAGICAL THING IS A SPELL

This distinction matters.

The Magic action can be used to:

CAST A SPELL

but also to:

USE A MAGICAL FEATURE

or:

ACTIVATE A MAGIC ITEM

when that feature or item says it requires:

A MAGIC ACTION

 

Therefore:

MAGIC ACTION ≠ AUTOMATICALLY CASTING A SPELL

EXAMPLE

A magical feature says:

"AS A MAGIC ACTION..."

Using it is:

A MAGIC ACTION

But it isn't necessarily:

CASTING A SPELL

unless the feature actually says that it is.

PART FIVE — SOME SPELLS CREATE LATER MAGIC ACTIONS

A spell can also create an effect you later operate with:

A MAGIC ACTION

This doesn't necessarily mean you are:

CASTING THE SPELL AGAIN

EXAMPLE — FLAME BLADE

Flame Blade has:

CASTING TIME: BONUS ACTION

Once active, the spell says you can later use:

A MAGIC ACTION

to make an attack with the fiery blade.

So:

Turn 1 Bonus Action:

CAST FLAME BLADE

Later Magic Action:

USE THE SPELL'S EXISTING EFFECT

That later Magic action doesn't itself mean:

CAST FLAME BLADE AGAIN

PART SIX — BONUS ACTION SPELLS

Some spells have:

CASTING TIME: BONUS ACTION

A Bonus Action is an additional action available only when:

A RULE SPECIFICALLY GIVES YOU SOMETHING TO DO AS A BONUS ACTION

You can take:

ONLY ONE BONUS ACTION ON YOUR TURN

 

IMPORTANT

You do not normally possess:

TWO BONUS ACTIONS

even if you know several Bonus Action spells.

You must choose:

WHICH ONE

to use.

PART SEVEN — BONUS ACTIONS HAPPEN ON YOUR TURN

The general Bonus Action rules say that you can take a Bonus Action:

ON YOUR TURN

and normally choose when during that turn to take it unless:

ITS TIMING IS SPECIFIED

 

So a Bonus Action spell is normally integrated into:

YOUR OWN TURN

PART EIGHT — MISTY STEP EXAMPLE

Misty Step:

LEVEL 2

Casting Time:

BONUS ACTION

Effect:

TELEPORT UP TO 30 FEET

to an unoccupied space you can see.

A typical turn might therefore be:

Movement.

Magic-related Bonus Action:

MISTY STEP

Then:

YOUR ACTION

can still potentially be used for something legal.

PART NINE — A BONUS ACTION SPELL DOESN'T USE YOUR ACTION

This is a fundamental action-economy advantage.

Suppose you cast:

MISTY STEP

with your Bonus Action.

You haven't spent:

YOUR ACTION

You can still use your Action for:

ATTACK

DASH

DODGE

MAGIC

or another legal action.

But spell-slot restrictions can affect whether another spell is legal.

That brings us to:

THE MOST IMPORTANT RULE IN THIS LESSON

PART TEN — ONE SPELL WITH A SPELL SLOT PER TURN

SRD 5.2.1 says:

ON A TURN, YOU CAN EXPEND ONLY ONE SPELL SLOT TO CAST A SPELL

 

This is the rule to memorize.

NOT

ONE SPELL PER TURN

NOT

ONLY ONE MAGIC ACTION PER TURN

NOT

YOU CAN NEVER CAST AN ACTION SPELL AND A BONUS ACTION SPELL TOGETHER

The actual restriction is specifically:

HOW MANY SPELL SLOTS YOU EXPEND TO CAST SPELLS ON THAT TURN

Maximum:

ONE

PART ELEVEN — FIRST LEGAL COMBINATION

You cast:

MISTY STEP

Bonus Action.

Misty Step uses:

A LEVEL 2 SPELL SLOT

You have now expended:

ONE SPELL SLOT

on this turn.

Can you then cast:

FIRE BOLT

with your Action?

YES

Fire Bolt is:

A CANTRIP

Cantrips expend:

NO SPELL SLOT

Therefore the total slots expended to cast spells this turn remains:

ONE

TURN

Bonus Action:

MISTY STEP — 1 SLOT

Action:

FIRE BOLT — 0 SLOTS

Total spell slots expended to cast spells:

1

Legal.

PART TWELVE — SECOND ILLEGAL COMBINATION

You cast:

MISTY STEP

Bonus Action:

ONE SPELL SLOT

Then you want to cast:

FIREBALL

with your Magic action.

Fireball would also require:

A SPELL SLOT

That would make:

TWO SPELL SLOTS

expended to cast spells on:

THE SAME TURN

Therefore:

NOT ALLOWED

under the SRD rule.

PART THIRTEEN — THE ORDER DOESN'T SOLVE THE PROBLEM

Suppose you reverse the sequence.

First:

FIREBALL

using a Spell Slot.

Then:

MISTY STEP

using a Spell Slot.

Still:

TWO SLOTS ON THE SAME TURN

So:

NOT ALLOWED

Changing the order doesn't change:

THE NUMBER OF SPELL SLOTS EXPENDED

PART FOURTEEN — BONUS ACTION CANTRIP + SLOTTED ACTION SPELL

Now consider:

SHILLELAGH

It is a:

CANTRIP

with:

CASTING TIME: BONUS ACTION

 

Cantrip:

NO SPELL SLOT

Suppose a character legitimately has both Shillelagh and an Action spell such as Fireball.

Bonus Action:

SHILLELAGH — 0 SLOTS

Magic Action:

FIREBALL — 1 SLOT

Total:

ONE SPELL SLOT

This satisfies:

THE ONE-SLOT-PER-TURN RULE

assuming every other requirement is met.

PART FIFTEEN — THE RULE CARES ABOUT SLOT EXPENDITURE

A very useful question is:

"HOW MANY SPELL SLOTS HAVE I EXPENDED TO CAST SPELLS THIS TURN?"

If the answer would become:

TWO

the second casting isn't allowed under this rule.

If the answer remains:

ZERO OR ONE

the one-slot rule itself doesn't prevent the combination.

Other rules still might.

PART SIXTEEN — A SPELL CAST FOR FREE

Suppose a feature allows you to cast a spell:

WITHOUT EXPENDING A SPELL SLOT

That casting contributes:

ZERO EXPENDED SPELL SLOTS

to this particular limit.

So the one-slot rule does not, by itself, forbid combining that slotless spell with another spell that:

DOES EXPEND ONE SLOT

provided:

ACTION ECONOMY

CASTING TIMES

TRIGGERS

and all other requirements allow it.

IMPORTANT

A spell cast without a slot remains:

A SPELL

But for this particular rule:

IT DIDN'T EXPEND A SPELL SLOT

PART SEVENTEEN — THIS RULE IS "PER TURN," NOT "PER ROUND"

This is crucial.

Combat is divided into:

ROUNDS

Each participant takes:

A TURN

A round represents about:

6 SECONDS

and contains multiple creatures' turns.

The spellcasting restriction says:

PER TURN

not:

PER ROUND

PART EIGHTEEN — WHY THAT MATTERS

Suppose on:

YOUR TURN

you cast Fireball using:

ONE SPELL SLOT

Later, during:

AN ENEMY'S TURN

the enemy hits you.

Shield has a:

REACTION

casting time triggered by certain events.

Can you potentially cast Shield using a Spell Slot?

YES

as far as the one-slot-per-turn restriction is concerned.

Why?

Fireball's slot was expended on:

YOUR TURN

Shield's slot would be expended on:

THE ENEMY'S TURN

Those are:

DIFFERENT TURNS

PART NINETEEN — ONE ROUND CAN CONTAIN MULTIPLE SLOTTED SPELLS

Because the restriction is per:

TURN

not per:

ROUND

a spellcaster can potentially expend a slot:

ON THEIR OWN TURN

and another slot:

ON ANOTHER CREATURE'S TURN

through a legal Reaction spell.

The limitation resets because:

IT IS A DIFFERENT TURN

PART TWENTY — REACTION SPELL ON YOUR OWN TURN

A Reaction can occur:

ON YOUR TURN

or:

ON SOMEONE ELSE'S TURN

 

This creates an important consequence.

Suppose you already cast a slotted spell:

ON YOUR TURN

Then something during that same turn triggers a Reaction spell that also requires:

A SPELL SLOT

Casting it would require spending:

A SECOND SLOT ON THE SAME TURN

So the one-slot rule prevents that second slotted spell.

PART TWENTY-ONE — COUNTERSPELL ON YOUR OWN TURN

Imagine:

You cast a spell using:

A SPELL SLOT

An enemy reacts to your casting.

Something then gives you the opportunity to cast:

COUNTERSPELL

as your Reaction.

Counterspell is:

LEVEL 3

and normally requires:

A SPELL SLOT

 

If this is still:

YOUR TURN

you have already expended one Spell Slot to cast a spell.

A normal slotted Counterspell would require:

A SECOND

Therefore:

YOU CAN'T EXPEND THAT SECOND SLOT TO CAST IT ON THE SAME TURN

under the SRD 5.2.1 rule.

This is a direct application of:

ONE SPELL WITH A SPELL SLOT PER TURN

PART TWENTY-TWO — COUNTERSPELL ON ANOTHER CREATURE'S TURN

Now reverse it.

An enemy casts a spell:

ON THE ENEMY'S TURN

Your Counterspell Reaction triggers.

You haven't yet expended a Spell Slot to cast a spell on:

THAT ENEMY'S TURN

You may therefore expend:

ONE SPELL SLOT

for Counterspell, assuming all of Counterspell's requirements are satisfied.

PART TWENTY-THREE — REACTIONS

A Reaction is:

AN INSTANT RESPONSE TO A TRIGGER

The trigger can occur:

ON YOUR TURN

or:

ON SOMEONE ELSE'S TURN

Once you take a Reaction:

YOU CAN'T TAKE ANOTHER REACTION

until:

THE START OF YOUR NEXT TURN

 

PART TWENTY-FOUR — REACTION SPELLS REQUIRE SPECIFIC TRIGGERS

You cannot simply decide:

"I CAST SHIELD NOW."

Reaction spells define:

WHEN

their Reaction can occur.

The spell's Casting Time entry provides:

THE TRIGGER

 

PART TWENTY-FIVE — SHIELD

Shield:

LEVEL 1 ABJURATION

Casting Time:

REACTION

The trigger is when:

YOU ARE HIT BY AN ATTACK ROLL

or:

TARGETED BY MAGIC MISSILE

 

You cannot use Shield merely because:

"I THINK SOMEONE MIGHT ATTACK ME LATER."

You need:

THE TRIGGER

PART TWENTY-SIX — HELLISH REBUKE

Hellish Rebuke:

LEVEL 1

Casting Time:

REACTION

Trigger:

YOU TAKE DAMAGE FROM A CREATURE YOU CAN SEE WITHIN 60 FEET

 

Notice the timing difference.

Shield responds to:

BEING HIT

or Magic Missile targeting.

Hellish Rebuke responds after:

TAKING DAMAGE

Different Reaction spells can therefore have:

DIFFERENT TRIGGER WINDOWS

PART TWENTY-SEVEN — COUNTERSPELL

Counterspell:

LEVEL 3

Casting Time:

REACTION

Trigger:

You see a creature within:

60 FEET

casting a spell that has:

VERBAL

SOMATIC

or:

MATERIAL

components.

Again:

READ THE TRIGGER

Don't treat "Reaction spell" as one generic timing rule.

PART TWENTY-EIGHT — YOU MAY ONLY HAVE ONE REACTION AVAILABLE

Suppose you cast:

SHIELD

as your Reaction.

Later, before the start of your next turn, someone casts a spell and you would like to use:

COUNTERSPELL

Can you?

Normally:

NO

You already used:

YOUR REACTION

You don't regain it until:

THE START OF YOUR NEXT TURN

 

PART TWENTY-NINE — REACTION ECONOMY AND SPELL SLOTS ARE SEPARATE LIMITS

A Reaction spell must pass:

TWO DIFFERENT CHECKS

First:

DO I HAVE MY REACTION?

Second:

CAN I LEGALLY EXPEND A SPELL SLOT ON THIS TURN?

EXAMPLE

You haven't used your Reaction.

But earlier on this same turn you already spent:

ONE SPELL SLOT

to cast a spell.

A triggered Reaction spell would require:

ANOTHER SLOT

The Reaction resource is available.

But:

THE SPELL-SLOT-PER-TURN RULE PREVENTS THE CASTING

These are:

DIFFERENT LIMITS

PART THIRTY — BONUS ACTION SPELL TRIGGERS

Most players think of Bonus Action spells as:

"USE WHENEVER ON MY TURN"

But some Bonus Action spells also define:

A SPECIFIC TRIGGER

The SRD explicitly warns that some Bonus Action spells work this way.

PART THIRTY-ONE — DIVINE SMITE EXAMPLE

Divine Smite:

LEVEL 1

Casting Time:

BONUS ACTION

But not just any Bonus Action.

It must be taken:

IMMEDIATELY AFTER HITTING A TARGET

with:

A MELEE WEAPON

or:

AN UNARMED STRIKE

 

So you cannot cast Divine Smite:

BEFORE YOU KNOW WHETHER THE ATTACK HIT

The trigger determines:

THE TIMING

PART THIRTY-TWO — BONUS ACTION TRIGGERS OVERRIDE FREE TIMING

General Bonus Action rule:

YOU CHOOSE WHEN DURING YOUR TURN

unless:

TIMING IS SPECIFIED

 

Divine Smite specifies:

IMMEDIATELY AFTER THE HIT

Therefore you follow:

THE SPECIFIC SPELL TIMING

PART THIRTY-THREE — BONUS ACTION COMPETITION

Suppose a Paladin has several possible Bonus Actions:

LAY ON HANDS

DIVINE SMITE

ANOTHER BONUS ACTION SPELL

You can still take only:

ONE BONUS ACTION

on that turn.

So even if several triggers and options are legal:

YOU MUST CHOOSE

PART THIRTY-FOUR — CASTING TIME OF 1 MINUTE OR MORE

Some spells are intentionally too slow to complete with:

ONE ACTION

The SRD calls these:

LONGER CASTING TIMES

Examples include spells requiring:

1 MINUTE

10 MINUTES

or:

HOURS

 

PART THIRTY-FIVE — THE LONG-CASTING PROCEDURE

While casting a spell whose Casting Time is:

1 MINUTE OR MORE

you must:

TAKE THE MAGIC ACTION ON EACH OF YOUR TURNS

and:

MAINTAIN CONCENTRATION

throughout the casting.

CORE LOOP

Turn 1:

MAGIC ACTION — CONTINUE CASTING

Turn 2:

MAGIC ACTION — CONTINUE CASTING

Turn 3:

MAGIC ACTION — CONTINUE CASTING

and so on until:

THE REQUIRED CASTING TIME IS COMPLETED

PART THIRTY-SIX — ONE MINUTE IN COMBAT

One combat round represents about:

6 SECONDS

 

Therefore one minute is approximately:

10 ROUNDS

So attempting to cast a:

1-MINUTE SPELL

during active combat is a major commitment.

This is a derived timing comparison.

PART THIRTY-SEVEN — CREATE UNDEAD EXAMPLE

Create Undead has:

CASTING TIME: 1 MINUTE

 

If attempted during structured combat, the caster must continue spending:

THE MAGIC ACTION

each turn of that casting while maintaining:

CONCENTRATION

until the casting is completed.

PART THIRTY-EIGHT — TEN-MINUTE SPELLS

Control Weather has:

CASTING TIME: 10 MINUTES

 

Ten minutes is far beyond:

A NORMAL COMBAT TURN

This is the kind of spell that usually requires:

TIME

SAFETY

or:

PROTECTION

to complete.

That is gameplay interpretation based on its actual Casting Time.

PART THIRTY-NINE — LONG CASTING REQUIRES CONCENTRATION EVEN BEFORE THE SPELL IS FINISHED

This is subtle but important.

During a long casting:

YOU MUST MAINTAIN CONCENTRATION

That concentration requirement exists while:

CASTING

even if the finished spell's Duration isn't itself:

CONCENTRATION

The casting process itself requires your focus.

PART FORTY — DAMAGE CAN THREATEN A LONG CASTING

The Concentration rules say that when you take damage while concentrating, you make:

A CONSTITUTION SAVING THROW

DC:

10

or:

HALF THE DAMAGE TAKEN, ROUNDED DOWN

whichever is higher,

to a maximum DC of:

30

 

EXAMPLE

You are casting a:

1-MINUTE SPELL

An enemy deals:

18 DAMAGE

Half:

18 ÷ 2 =

9

Compare:

9

versus:

10

Concentration save DC:

10

ANOTHER EXAMPLE

Damage:

30

Half:

15

DC:

15

PART FORTY-ONE — IF CONCENTRATION BREAKS DURING LONG CASTING

The result is:

THE SPELL FAILS

But:

YOU DON'T EXPEND A SPELL SLOT

To attempt the spell again:

START OVER

 

EXAMPLE

You have spent:

8 ROUNDS

casting a 1-minute spell.

Concentration breaks before completion.

Result:

NO SPELL

Spell Slot:

NOT EXPENDED

Progress:

LOST

To cast again:

BEGIN FROM THE START

PART FORTY-TWO — LONG CASTING COMPETES WITH OTHER CONCENTRATION

The Concentration rule says you lose Concentration on one effect when you begin:

ANOTHER EFFECT REQUIRING CONCENTRATION

 

A long casting itself requires:

CONCENTRATION

Therefore you cannot normally maintain:

ANOTHER CONCENTRATION EFFECT

at the same time as that long casting.

EXAMPLE

You are concentrating on:

HEX

Then you begin a 1-minute spell.

The longer casting requires:

CONCENTRATION

You cannot continue maintaining both.

PART FORTY-THREE — INCAPACITATED ENDS CONCENTRATION

The Concentration rules also say concentration ends if:

YOU HAVE THE INCAPACITATED CONDITION

or:

YOU DIE

 

Therefore either event can ruin:

A LONG CASTING

because the casting depends on maintaining:

CONCENTRATION

PART FORTY-FOUR — LONGER CASTING OCCUPIES YOUR ACTION EACH TURN

Because you must take:

THE MAGIC ACTION

each turn, you aren't free to take a different normal Action on those turns while continuing the casting.

You still may have:

MOVEMENT

A BONUS ACTION

or:

A REACTION

if another rule permits them and nothing about the situation prevents them.

But your Action is committed to:

MAGIC

each turn of the long casting.

IMPORTANT

Any other activity must still respect:

CONCENTRATION

SPELL-CASTING LIMITS

and:

THE SPECIFIC RULES INVOLVED

PART FORTY-FIVE — RITUAL CASTING

Certain spells have:

THE RITUAL TAG

Such a spell can be cast:

NORMALLY

or:

AS A RITUAL

 

NORMAL VERSION

Use:

NORMAL CASTING TIME

and, if appropriate:

EXPEND A SPELL SLOT

RITUAL VERSION

Takes:

10 MINUTES LONGER

and:

EXPENDS NO SPELL SLOT

PART FORTY-SIX — GENERAL RITUAL REQUIREMENT

Under the general rule, to cast a spell as a Ritual:

YOU MUST HAVE THE SPELL PREPARED

 

Specific features can change this.

WIZARD EXCEPTION

As learned in Lesson 71, Wizard:

RITUAL ADEPT

can allow an eligible Ritual spell in the Wizard's Spellbook to be cast as a Ritual without having it normally prepared.

That is:

A SPECIFIC CLASS EXCEPTION

PART FORTY-SEVEN — RITUALS SAVE SPELL SLOTS

This is their primary resource advantage.

Normal:

SPEND A SPELL SLOT

Ritual:

SPEND NO SPELL SLOT

The cost is:

TIME

PART FORTY-EIGHT — RITUALS TAKE EXACTLY 10 MINUTES LONGER

The rule is not:

"RITUALS ALWAYS TAKE 10 MINUTES"

It is:

NORMAL CASTING TIME + 10 MINUTES

 

EXAMPLE

Normal spell:

CASTING TIME 1 MINUTE

Ritual version:

1 + 10 =

11 MINUTES

PART FORTY-NINE — RITUALS CANNOT BE UPCAST

The Rules Glossary makes an important consequence explicit.

Because the Ritual version:

DOESN'T EXPEND A SPELL SLOT

it:

CAN'T BE CAST AT A HIGHER LEVEL

 

EXAMPLE

Suppose a level 1 Ritual spell has a stronger effect when using:

A LEVEL 3 SLOT

If you cast it as:

A RITUAL

there is:

NO SPELL SLOT

Therefore you can't choose:

"LEVEL 3 RITUAL"

through the normal higher-slot procedure.

PART FIFTY — RITUAL CASTING IS ALSO A LONG CASTING

Because a Ritual takes:

AT LEAST 10 MINUTES LONGER

it falls under:

LONGER CASTING TIMES

During the Ritual casting, you therefore must:

TAKE THE MAGIC ACTION ON EACH TURN

and:

MAINTAIN CONCENTRATION

 

PART FIFTY-ONE — RITUALS CAN BE INTERRUPTED

If your Concentration breaks while casting the Ritual:

THE SPELL FAILS

You have spent:

NO SPELL SLOT

because Rituals expend none anyway.

To try again:

START OVER

PART FIFTY-TWO — RITUALS ARE GENERALLY BAD EMERGENCY COMBAT OPTIONS

This isn't a new rule.

It follows from:

THE CASTING TIME

Adding ten minutes means a Ritual usually requires far more time than:

A NORMAL COMBAT ROUND

So Rituals are often most useful during:

EXPLORATION

TRAVEL

INVESTIGATION

PREPARATION

or other situations where:

TIME IS AVAILABLE

PART FIFTY-THREE — RITUAL VERSUS NORMAL CASTING

Imagine a Ritual-tagged spell normally has:

CASTING TIME: ACTION

You urgently need it:

NOW

Normal casting:

MAGIC ACTION

and expend the appropriate Spell Slot.

If there is no urgency:

Cast as:

RITUAL

Time:

10 MINUTES LONGER

Slot:

NONE

That is a tactical choice between:

TIME

and:

MAGICAL RESOURCES

PART FIFTY-FOUR — READYING A SPELL

There is another timing mechanic worth connecting here:

READY

You can take the Ready action to prepare an action in response to:

A TRIGGER

For a spell to be Readied, it must have:

CASTING TIME: ACTION

 

PART FIFTY-FIVE — YOU CAST THE READIED SPELL NOW

This is extremely important.

When you Ready a spell:

YOU CAST IT AS NORMAL ON YOUR TURN

including expending any resources used to cast it.

Then you:

HOLD ITS ENERGY

until your chosen trigger occurs.

 

IT IS NOT

"Wait until later and then begin casting."

You already:

CAST THE SPELL

during your Ready action.

PART FIFTY-SIX — RELEASING THE READIED SPELL

When the trigger occurs, you use:

YOUR REACTION

to release:

THE HELD SPELL

If the trigger never occurs, or you choose not to respond:

THE HELD MAGIC CAN BE LOST

according to the Ready timing.

PART FIFTY-SEVEN — READYING A SPELL REQUIRES CONCENTRATION

Holding the spell's energy requires:

CONCENTRATION

You can maintain it until:

THE START OF YOUR NEXT TURN

 

If Concentration breaks:

THE SPELL DISSIPATES

without taking effect.

PART FIFTY-EIGHT — THE SPELL SLOT WAS ALREADY EXPENDED

This is an important difference from interrupted:

LONGER CASTING TIMES

When you Ready a spell:

YOU CAST IT AS NORMAL FIRST

and expend the resources at that time.

So if Concentration breaks while you're holding the Readied spell:

THE SPELL DISSIPATES

The resource has already been used.

COMPARE

LONG CASTING INTERRUPTED

Spell fails.

SLOT NOT EXPENDED

READIED SPELL LOSES CONCENTRATION

Spell was already cast.

RESOURCE ALREADY EXPENDED

These are:

DIFFERENT RULES

PART FIFTY-NINE — READY + ONE-SLOT-PER-TURN

Suppose on your turn you already cast:

MISTY STEP

using a Spell Slot.

Can you then Ready:

A LEVEL 1 ACTION SPELL

that would expend another Spell Slot?

NO

Readying the spell requires you to:

CAST IT NOW

That would expend:

A SECOND SPELL SLOT

on:

THE SAME TURN

The one-slot-per-turn rule prevents it.

PART SIXTY — READYING A CANTRIP

Suppose instead you cast:

NO SLOTTED ACTION SPELL

and want to Ready:

FIRE BOLT

Fire Bolt is:

AN ACTION CANTRIP

It uses:

NO SPELL SLOT

It therefore qualifies as an Action spell for Ready, and the one-slot restriction doesn't create a problem.

You still need:

CONCENTRATION

to hold the Readied spell.

And releasing it still requires:

YOUR REACTION

PART SIXTY-ONE — READYING A BONUS ACTION SPELL

Can you Ready:

MISTY STEP

using the Ready spell rule?

NO

The Ready rule specifically says the spell must have:

A CASTING TIME OF AN ACTION

Misty Step has:

BONUS ACTION

So it doesn't qualify for:

READYING AS A SPELL

under that rule.

PART SIXTY-TWO — READYING A REACTION SPELL

Likewise:

SHIELD

has:

CASTING TIME: REACTION

It doesn't qualify for the Ready-spell procedure requiring:

CASTING TIME: ACTION

Shield already has:

ITS OWN TRIGGER

PART SIXTY-THREE — TURN VERSUS ROUND: COMPLETE EXAMPLE

Initiative:

WIZARD

ORC

CULTIST

WIZARD'S TURN

Wizard casts:

FIREBALL

using one Spell Slot.

Slot spells this turn:

1

Cannot also cast:

MISTY STEP WITH ANOTHER SLOT

on that same turn.

ORC'S TURN

Orc attacks Wizard and hits.

Wizard still has Reaction.

Shield's trigger occurs.

This is:

ORC'S TURN

not the Wizard's.

Wizard can potentially expend:

ONE SPELL SLOT

to cast Shield.

CULTIST'S TURN

Cultist begins casting a spell.

Can Wizard now cast:

COUNTERSPELL?

Even though it is a new creature's turn for the one-slot rule, the Wizard already used:

THEIR REACTION

for Shield.

Reaction doesn't return until:

START OF THE WIZARD'S NEXT TURN

Therefore:

NO REACTION AVAILABLE

The limiting rule here is:

REACTION ECONOMY

not:

SPELL-SLOT-PER-TURN

PART SIXTY-FOUR — TWO DIFFERENT LIMITERS

This example teaches one of the most important spellcasting habits.

Before casting a Reaction or Bonus Action spell, ask:

DO I HAVE THE REQUIRED ACTION RESOURCE?

and:

CAN I LEGALLY EXPEND THE SPELL SLOT ON THIS TURN?

You often need to satisfy:

BOTH

PART SIXTY-FIVE — SPELLS CAN HAVE DIFFERENT CASTING TIMES FROM THEIR LATER EFFECTS

Do not confuse:

CASTING TIME

with actions the spell allows:

AFTER CASTING

EXAMPLE — FLAME BLADE

Cast:

BONUS ACTION

Later attack with blade:

MAGIC ACTION

EXAMPLE — HEX

Cast:

BONUS ACTION

If the target drops to 0 HP before the spell ends, the spell lets you use:

A BONUS ACTION ON A LATER TURN

to curse another creature.

That later Bonus Action is:

PART OF THE EXISTING SPELL'S EFFECT

It isn't necessarily a new casting of Hex.

PART SIXTY-SIX — DURATION IS NOT CASTING TIME

Another important distinction:

CASTING TIME

answers:

HOW LONG DOES IT TAKE TO CAST?

DURATION

answers:

HOW LONG DOES THE SPELL'S EFFECT LAST?

EXAMPLE

Shield:

Casting Time:

REACTION

Duration:

1 ROUND

 

Those are completely different entries.

ANOTHER EXAMPLE

Hex:

Casting Time:

BONUS ACTION

Duration:

CONCENTRATION, UP TO 1 HOUR

 

Fast to cast:

BONUS ACTION

Potentially long-lasting:

1 HOUR

Don't confuse the two.

PART SIXTY-SEVEN — CASTING TIME IS NOT ACTIVATION TIME AFTERWARD

A spell may create an effect that later requires:

AN ACTION

BONUS ACTION

REACTION

or:

MAGIC ACTION

That doesn't change the spell's original:

CASTING TIME

PART SIXTY-EIGHT — AT THE TABLE: ACTION SPELL

You want to cast:

FIRE BOLT

Check:

Casting Time:

ACTION

Procedure:

TAKE MAGIC ACTION

Slot:

NONE — CANTRIP

Resolve:

SPELL ATTACK AND EFFECT

PART SIXTY-NINE — AT THE TABLE: BONUS ACTION SPELL

You want:

MISTY STEP

Check:

Casting Time:

BONUS ACTION

Do you have:

YOUR BONUS ACTION?

Yes.

Have you already expended a Spell Slot to cast a spell:

THIS TURN?

If yes:

YOU CAN'T EXPEND ANOTHER ONE

for Misty Step.

If no:

CAST IT

Spend:

LEVEL 2+ SLOT

as allowed.

PART SEVENTY — AT THE TABLE: REACTION SPELL

Enemy does something.

Before announcing a Reaction spell:

CHECK THE TRIGGER

If trigger matches:

CHECK REACTION AVAILABLE

Then:

CHECK ONE-SLOT-PER-TURN RULE

Then:

CAST

PART SEVENTY-ONE — AT THE TABLE: LONG SPELL

Spell says:

1 MINUTE

On each turn:

MAGIC ACTION

Maintain:

CONCENTRATION

If damaged:

CONCENTRATION SAVE IF REQUIRED

If Concentration breaks:

SPELL FAILS

NO SLOT EXPENDED

and:

START OVER

PART SEVENTY-TWO — AT THE TABLE: RITUAL

Spell has:

RITUAL TAG

Under general rule:

HAVE IT PREPARED

Choose:

RITUAL VERSION

Add:

10 MINUTES

Spell Slot:

NONE

Higher-level casting:

NOT AVAILABLE THROUGH RITUAL

During casting:

MAGIC ACTION EACH TURN

CONCENTRATION

COMMON BEGINNER MISTAKES

MISTAKE 1 — THINKING EVERY SPELL USES THE MAGIC ACTION

No.

Some use:

BONUS ACTION

REACTION

or:

LONGER CASTING TIME

MISTAKE 2 — THINKING "ACTION" MEANS ATTACK ACTION

A spell with Casting Time:

ACTION

normally uses:

MAGIC ACTION

MISTAKE 3 — THINKING EVERY MAGIC ACTION CASTS A SPELL

Magic actions can also activate:

FEATURES

or:

MAGIC ITEMS

MISTAKE 4 — THINKING A BONUS ACTION SPELL CONSUMES YOUR NORMAL ACTION

It doesn't.

It consumes:

YOUR BONUS ACTION

MISTAKE 5 — THINKING YOU HAVE A BONUS ACTION EVERY TURN WHETHER OR NOT A RULE GIVES YOU ONE

You can take one only if a rule gives you:

A BONUS ACTION OPTION

MISTAKE 6 — TRYING TO USE TWO BONUS ACTIONS

Maximum:

ONE BONUS ACTION PER TURN

MISTAKE 7 — THINKING THE RULE IS "ONE SPELL PER TURN"

It isn't.

It is:

ONE SPELL SLOT EXPENDED TO CAST A SPELL PER TURN

MISTAKE 8 — FORBIDDING MISTY STEP + FIRE BOLT

Misty Step:

ONE SLOT

Fire Bolt:

ZERO SLOTS

Total:

ONE

Legal under this rule.

MISTAKE 9 — ALLOWING MISTY STEP + FIREBALL WITH BOTH USING SLOTS

That would expend:

TWO SPELL SLOTS

on one turn.

Not allowed.

MISTAKE 10 — APPLYING OLD BONUS-ACTION SPELL LOGIC INSTEAD OF THE SRD 5.2.1 RULE

Use the actual SRD 5.2.1 wording:

ONE SPELL SLOT PER TURN

Do not silently import different wording from earlier rulesets.

MISTAKE 11 — THINKING THE LIMIT IS ONE SLOT PER ROUND

It says:

TURN

MISTAKE 12 — THINKING A FIREBALL ON YOUR TURN PREVENTS SHIELD ON AN ENEMY'S TURN

Those are:

DIFFERENT TURNS

The one-slot rule can allow both.

MISTAKE 13 — TRYING TO SPEND A SECOND SPELL SLOT ON A REACTION DURING YOUR OWN TURN

If you already spent one to cast a spell on that same turn:

NO SECOND SLOT

MISTAKE 14 — CASTING SHIELD WITHOUT ITS TRIGGER

Shield requires:

ITS SPECIFIC REACTION TRIGGER

MISTAKE 15 — CASTING HELLISH REBUKE BEFORE TAKING DAMAGE

Its trigger specifically follows:

TAKING DAMAGE

from the qualifying creature.

MISTAKE 16 — CASTING COUNTERSPELL WHEN ITS TRIGGER ISN'T MET

Counterspell defines:

WHAT YOU MUST SEE

HOW FAR AWAY

and:

WHAT KIND OF SPELL CASTING

triggers it.

MISTAKE 17 — USING TWO REACTION SPELLS BEFORE YOUR NEXT TURN

You normally get:

ONE REACTION

until:

THE START OF YOUR NEXT TURN

MISTAKE 18 — THINKING EVERY BONUS ACTION SPELL CAN BE CAST AT ANY MOMENT ON YOUR TURN

Some specify:

A TRIGGER

MISTAKE 19 — CASTING DIVINE SMITE BEFORE YOU HIT

Its Casting Time specifies:

IMMEDIATELY AFTER THE HIT

MISTAKE 20 — THINKING A 1-MINUTE SPELL TAKES ONE ACTION

It requires:

REPEATED MAGIC ACTIONS

over the full Casting Time.

MISTAKE 21 — FORGETTING CONCENTRATION DURING LONGER CASTING

A casting of:

1 MINUTE OR MORE

requires:

CONCENTRATION

while casting.

MISTAKE 22 — THINKING THE SPELL SLOT IS LOST WHEN LONG CASTING IS INTERRUPTED BY BROKEN CONCENTRATION

The rule says:

NO SPELL SLOT IS EXPENDED

MISTAKE 23 — CONTINUING FROM WHERE YOU LEFT OFF

If Concentration breaks:

START OVER

MISTAKE 24 — TRYING TO MAINTAIN ANOTHER CONCENTRATION EFFECT DURING THE LONG CASTING

The long casting itself requires:

CONCENTRATION

MISTAKE 25 — THINKING A RITUAL ALWAYS TAKES EXACTLY 10 MINUTES

It takes:

10 MINUTES LONGER THAN NORMAL

MISTAKE 26 — SPENDING A SPELL SLOT ON THE RITUAL VERSION

Ritual:

NO SPELL SLOT

MISTAKE 27 — UPCASTING A RITUAL

Because no slot is spent:

THE RITUAL VERSION CAN'T BE CAST AT A HIGHER LEVEL

MISTAKE 28 — CASTING ANY SPELL AS A RITUAL

It must have:

THE RITUAL TAG

MISTAKE 29 — IGNORING THE GENERAL PREPARED-SPELL REQUIREMENT FOR RITUALS

Under the general rule:

HAVE IT PREPARED

Specific features may override this.

MISTAKE 30 — FORGETTING THAT RITUALS USE THE LONGER-CASTING RULES

They require:

MAGIC ACTIONS THROUGHOUT

and:

CONCENTRATION

MISTAKE 31 — THINKING READYING A SPELL MEANS YOU CAST IT LATER

No.

You:

CAST IT NOW

and:

RELEASE IT LATER

MISTAKE 32 — FORGETTING TO EXPEND THE RESOURCE WHEN READYING A SLOTTED SPELL

The spell is cast:

WHEN YOU READY IT

MISTAKE 33 — THINKING A LOST READIED SPELL REFUNDS THE SLOT

The slot was already:

EXPENDED

MISTAKE 34 — READYING A BONUS ACTION SPELL

The Ready spell rule requires:

CASTING TIME: ACTION

MISTAKE 35 — READYING A REACTION SPELL

Again:

CASTING TIME: ACTION

is required.

MISTAKE 36 — FORGETTING CONCENTRATION WHILE HOLDING A READIED SPELL

Holding it requires:

CONCENTRATION

QUICK RECAP

CASTING TIME

Tells you:

HOW LONG OR WHAT ACTION RESOURCE

is required to cast a spell.

ACTION SPELL

Use:

MAGIC ACTION

MAGIC ACTION

Can:

CAST AN ACTION SPELL

ACTIVATE A FEATURE

or:

ACTIVATE A MAGIC ITEM

when the relevant rule requires it.

BONUS ACTION SPELL

Uses:

BONUS ACTION

You have at most:

ONE BONUS ACTION PER TURN

Some Bonus Action spells have:

SPECIFIC TRIGGERS

REACTION SPELL

Uses:

REACTION

Requires:

ITS SPECIFIC TRIGGER

Reaction can occur:

ON YOUR TURN

or:

ANOTHER CREATURE'S TURN

After using it:

NO MORE REACTION

until:

START OF YOUR NEXT TURN

ONE SPELL WITH A SPELL SLOT PER TURN

On a turn:

YOU CAN EXPEND ONLY ONE SPELL SLOT TO CAST A SPELL

 

LEGAL

Misty Step with slot:

BONUS ACTION

Fire Bolt Cantrip:

MAGIC ACTION

Slots spent:

ONE

NOT LEGAL

Misty Step with slot:

BONUS ACTION

Fireball with slot:

MAGIC ACTION

Slots required:

TWO ON THE SAME TURN

DIFFERENT TURN

Slotted Action spell:

YOUR TURN

Slotted Reaction spell:

ENEMY TURN

Can be possible because:

DIFFERENT TURNS

LONGER CASTING

Casting Time:

1 MINUTE OR MORE

Each turn:

MAGIC ACTION

Must maintain:

CONCENTRATION

If Concentration breaks:

SPELL FAILS

NO SPELL SLOT EXPENDED

START OVER

RITUAL

Requires:

RITUAL TAG

General rule:

SPELL PREPARED

Time:

NORMAL + 10 MINUTES

Spell Slot:

NONE

Higher-level casting:

NO

READY SPELL

Must have:

CASTING TIME: ACTION

You:

CAST IT NOW

Hold with:

CONCENTRATION

Release with:

REACTION

If the held spell dissipates:

RESOURCES ALREADY USED ARE NOT REFUNDED

 

PRIME HERO CHALLENGE

A Sorcerer has:

FIRE BOLT

MISTY STEP

SHIELD

and:

COUNTERSPELL

They have all required Spell Slots available.

SCENARIO ONE

On the Sorcerer's turn:

Bonus Action:

MISTY STEP

using a level 2 Spell Slot.

Can the Sorcerer then cast:

FIRE BOLT

with the Magic action?

YES

Misty Step:

1 SLOT

Fire Bolt:

0 SLOTS

Total:

ONE SLOT

SCENARIO TWO

Instead, after Misty Step the Sorcerer wants to cast:

AN ACTION SPELL USING ANOTHER SLOT

Can they?

NO

That would require:

TWO SPELL SLOTS ON THE SAME TURN

SCENARIO THREE

Sorcerer casts a slotted Action spell on:

THEIR TURN

Later an enemy attacks during:

THE ENEMY'S TURN

and triggers Shield.

Can Shield potentially be cast?

YES

The slot restriction is:

PER TURN

The enemy's turn is:

A DIFFERENT TURN

SCENARIO FOUR

The Sorcerer casts a slotted spell on their turn.

During that same turn, an enemy's Reaction creates an opportunity for the Sorcerer to cast Counterspell.

Can the Sorcerer spend another normal Spell Slot on Counterspell?

NO

It is still:

THE SORCERER'S TURN

They already spent:

ONE SPELL SLOT TO CAST A SPELL

SCENARIO FIVE

The Sorcerer uses Shield during:

AN ENEMY'S TURN

A second enemy later acts before the Sorcerer's next turn and casts a spell.

Can the Sorcerer use Counterspell?

NO

Not because of the one-slot-per-turn rule.

The second enemy has:

A DIFFERENT TURN

The problem is:

THE SORCERER ALREADY USED THEIR REACTION

It doesn't return until:

THE START OF THE SORCERER'S NEXT TURN

RITUAL CHALLENGE

A spell has:

RITUAL

Normal Casting Time:

1 MINUTE

How long does the Ritual version take?

1 + 10 =

11 MINUTES

Spell Slot expended?

NO

Can you cast the Ritual version using a higher-level slot?

NO

because Ritual casting:

DOESN'T EXPEND A SLOT

LONG CASTING CHALLENGE

You are casting a:

1-MINUTE SPELL

After several rounds, you take:

26 DAMAGE

Concentration DC:

26 ÷ 2 =

13

Compare with minimum 10:

DC 13

You fail.

What happens?

SPELL FAILS

Spell Slot:

NOT EXPENDED

Can you resume at the same point?

NO

You must:

START OVER

READY CHALLENGE

You Ready:

FIRE BOLT

Trigger:

"WHEN THE OGRE STEPS THROUGH THE DOOR."

Fire Bolt has:

CASTING TIME: ACTION

Can it be Readied?

YES

When do you actually cast it?

ON YOUR TURN WHEN YOU TAKE THE READY ACTION

What do you do later when the trigger happens?

USE YOUR REACTION TO RELEASE IT

What must you maintain while holding it?

CONCENTRATION

LESSON 73 — KEY TAKEAWAYS

Spellcasting isn't only about:

SPELLS

and:

SPELL SLOTS

It is also about:

TIME

Every spell occupies a place in:

THE ACTION ECONOMY

The first thing to read after a spell's name and level should often be:

CASTING TIME

because that tells you whether the spell competes for:

YOUR ACTION

YOUR BONUS ACTION

YOUR REACTION

or:

MANY TURNS OF CONCENTRATION

The central SRD 5.2.1 spell-timing rule is:

ONE SPELL SLOT EXPENDED TO CAST A SPELL PER TURN

That is not the same as:

ONE SPELL PER TURN

A slotted spell plus a Cantrip can often coexist on the same turn if:

THEIR CASTING TIMES FIT

A spell cast without a slot can potentially coexist with a slotted spell for the same reason.

But:

TWO SPELLS THAT EACH REQUIRE EXPENDING A SLOT

can't both be cast on:

THE SAME TURN

Reaction spells add another layer:

CHECK THE TRIGGER

CHECK YOUR REACTION

CHECK WHICH TURN IT IS

CHECK SPELL-SLOT EXPENDITURE

Long spells transform casting into:

A MULTI-TURN PROJECT

They demand:

MAGIC ACTIONS

and:

CONCENTRATION

throughout the casting.

And Rituals offer one of the game's most important magical trades:

MORE TIME

in exchange for:

NO SPELL SLOT

Once you understand all of that, you can answer:

WHEN CAN I CAST THIS SPELL?

The next question is:

WHERE CAN I CAST IT, AND WHO OR WHAT CAN I AFFECT?

NEXT LESSON

LESSON 74 — RANGE, TARGETS, AND AREAS OF EFFECT

We will learn exactly how spells interact with:

DISTANCE

TOUCH

SELF

TARGETS

CREATURES

OBJECTS

POINTS IN SPACE

and:

AREAS OF EFFECT

including:

CONES

CUBES

CYLINDERS

EMANATIONS

LINES

and:

SPHERES

We will also cover:

POINTS OF ORIGIN

WHETHER THE ORIGIN IS INCLUDED

TOTAL COVER

MOVABLE SPELL EFFECTS

and how to determine exactly:

WHO IS INSIDE A SPELL'S AREA

before Lesson 75 moves into:

VERBAL, SOMATIC, AND MATERIAL COMPONENTS

SRD 5.2.1 ATTRIBUTION

This work includes material from the System Reference Document 5.2.1 (“SRD 5.2.1”) by Wizards of the Coast LLC, available at https://www.dndbeyond.com/srd. The SRD 5.2.1 is licensed under the Creative Commons Attribution 4.0 International License, available at https://creativecommons.org/licenses/by/4.0/legalcode.