Secret Lesson 77

Spell Duration and Concentration: Instantaneous Magic, Time-Span Effects, Maintaining Spells, Taking Damage, and Losing Concentration

In the previous lessons, we learned:

WHICH SPELLS YOU CAN CAST

WHAT SPELL SLOTS POWER THEM

WHEN YOU CAN CAST THEM

WHERE THEY CAN REACH

and:

WHAT COMPONENTS THEY REQUIRE

Now we ask:

HOW LONG DOES THE MAGIC LAST?

Some spells exist for:

A SINGLE MOMENT

Others continue for:

ONE ROUND

ONE MINUTE

TEN MINUTES

ONE HOUR

EIGHT HOURS

or even:

UNTIL DISPELLED

And many of the most powerful ongoing spells require the caster to maintain:

CONCENTRATION

Concentration creates one of the most important tactical limitations in 5E:

YOU CAN'T MAINTAIN MULTIPLE CONCENTRATION EFFECTS AT ONCE

If you choose to begin another one:

THE FIRST ENDS

And enemies can attack you specifically to try to:

BREAK YOUR CONCENTRATION

PART ONE — WHAT IS SPELL DURATION?

A spell's:

DURATION

is the length of time the spell persists:

AFTER IT IS CAST

The SRD identifies three typical forms:

CONCENTRATION

INSTANTANEOUS

and:

TIME SPAN

PART TWO — THE THREE BASIC DURATION TYPES

1. INSTANTANEOUS

The magic appears:

FOR A MOMENT

and then:

DISAPPEARS

2. TIME SPAN

The spell lasts for a stated period such as:

1 ROUND

1 MINUTE

1 HOUR

8 HOURS

or another specified duration.

3. CONCENTRATION

The effect remains active only while its creator:

MAINTAINS CONCENTRATION

up to the maximum duration stated by the effect.

PART THREE — DURATION IS NOT CASTING TIME

This distinction is essential.

CASTING TIME

means:

HOW LONG IT TAKES TO CAST THE SPELL

DURATION

means:

HOW LONG THE EFFECT PERSISTS AFTER CASTING

EXAMPLE — SHIELD

Casting Time:

REACTION

Duration:

1 ROUND

It is cast:

ALMOST INSTANTLY AS A REACTION

but continues protecting you until:

THE START OF YOUR NEXT TURN

as stated by the spell.

EXAMPLE — MAGIC CIRCLE

Casting Time:

1 MINUTE

Duration:

1 HOUR

So:

ONE MINUTE TO CREATE IT

then:

ONE HOUR OF EFFECT

These are completely different measurements.

PART FOUR — INSTANTANEOUS DURATION

An:

INSTANTANEOUS

spell has magic that appears only:

FOR A MOMENT

and then disappears.

EXAMPLE — FIREBALL

Fireball:

DURATION: INSTANTANEOUS

The explosion occurs.

Creatures take damage.

Then:

THE FIREBALL SPELL ITSELF IS NO LONGER ONGOING

PART FIVE — INSTANTANEOUS DOES NOT MEAN "NO LASTING CONSEQUENCES"

This is a subtle but very important concept.

An instantaneous spell's:

MAGIC

exists only momentarily.

But what that magic causes can still matter:

AFTERWARD

FIREBALL EXAMPLE

Fireball is:

INSTANTANEOUS

but its spell description says flammable objects in the area that aren't being worn or carried:

START BURNING

The Fireball's magical duration has ended.

But the world may now contain:

BURNING OBJECTS

That is a consequence of what the instantaneous spell did.

PART SIX — FINGER OF DEATH: ANOTHER INSTANTANEOUS EXAMPLE

Finger of Death has:

DURATION: INSTANTANEOUS

Yet a Humanoid killed by it rises at the start of your next turn as:

A ZOMBIE

under the spell's rules.

Again:

INSTANTANEOUS DURATION

does not mean:

EVERYTHING CAUSED BY THE SPELL VANISHES IMMEDIATELY

PART SEVEN — HEROES' FEAST MAKES THIS EVEN CLEARER

Heroes' Feast has:

DURATION: INSTANTANEOUS

Yet creatures who consume the feast receive benefits lasting:

24 HOURS

So spell duration and duration of every later consequence are not necessarily:

THE SAME NUMBER

The spell description tells you exactly what happens.

PART EIGHT — DON'T TRY TO "BREAK CONCENTRATION" ON AN INSTANTANEOUS SPELL

Fireball requires:

NO CONCENTRATION

Once it is cast and resolved:

IT HAS ALREADY HAPPENED

You can't attack the caster afterward and somehow:

UN-EXPLODE THE FIREBALL

The Concentration system applies only when:

THE EFFECT REQUIRES CONCENTRATION

PART NINE — TIME-SPAN DURATION

A Time Span tells you how long the spell lasts in:

ROUNDS

MINUTES

HOURS

or another stated period.

Examples include:

1 ROUND

1 MINUTE

1 HOUR

8 HOURS

PART TEN — SHIELD

Shield:

DURATION: 1 ROUND

Its spell text then clarifies that its AC bonus lasts until:

THE START OF YOUR NEXT TURN

This is a short:

NON-CONCENTRATION

duration.

PART ELEVEN — LONGSTRIDER

Longstrider:

DURATION: 1 HOUR

It increases the target's Speed by:

10 FEET

until the spell ends.

No Concentration appears in the Duration entry.

Therefore:

LONGSTRIDER DOES NOT REQUIRE CONCENTRATION

PART TWELVE — MAGE ARMOR

Mage Armor:

DURATION: 8 HOURS

It gives an eligible target a base AC of:

13 + DEXTERITY MODIFIER

until the spell ends.

Again:

NO CONCENTRATION

So taking damage does not trigger:

A CONCENTRATION SAVE FOR MAGE ARMOR

PART THIRTEEN — NON-CONCENTRATION SPELLS CAN END EARLY FOR OTHER REASONS

Mage Armor normally lasts:

8 HOURS

but it ends early if:

THE TARGET DONS ARMOR

That demonstrates another major principle:

MAXIMUM OR LISTED DURATION IS NOT ALWAYS THE ONLY END CONDITION

Read:

THE SPELL DESCRIPTION

PART FOURTEEN — SHILLELAGH

Shillelagh has:

DURATION: 1 MINUTE

but ends early if:

YOU CAST IT AGAIN

or:

YOU LET GO OF THE WEAPON

Again:

SPELL-SPECIFIC END CONDITIONS

can end a spell before its listed Time Span expires.

PART FIFTEEN — MAGE HAND

Mage Hand lasts:

1 MINUTE

but vanishes early if it is ever more than:

30 FEET AWAY FROM YOU

or if:

YOU CAST THE SPELL AGAIN

Duration tells you:

THE MAXIMUM NORMAL PERIOD

The spell text can still impose:

EARLIER END CONDITIONS

PART SIXTEEN — DISMISSING A TIME-SPAN SPELL

The general spell Duration rule says that while a Time-Span spell you cast is ongoing:

YOU CAN DISMISS IT

requiring:

NO ACTION

provided you don't have:

THE INCAPACITATED CONDITION

EXAMPLE

You cast a non-Concentration spell lasting:

1 HOUR

Twenty minutes later, you decide you no longer want the spell active.

If you're not Incapacitated:

YOU CAN DISMISS IT

No Action.

No Bonus Action.

No Reaction.

PART SEVENTEEN — DISMISSAL IS NOT THE SAME AS DISPEL MAGIC

You can dismiss:

YOUR OWN ONGOING TIME-SPAN SPELL

under this general rule.

That is not the same mechanic as:

DISPEL MAGIC

which is a spell used to end eligible magical effects according to its own rules.

PART EIGHTEEN — WHAT IS CONCENTRATION?

Some spells and other effects require:

CONCENTRATION

to remain active.

If the effect's creator loses Concentration:

THE EFFECT ENDS

That is the fundamental rule.

PART NINETEEN — CONCENTRATION DURATION USES "UP TO"

A Concentration spell often says something like:

CONCENTRATION, UP TO 1 MINUTE

or:

CONCENTRATION, UP TO 1 HOUR

That means the stated time is:

A MAXIMUM

not a guarantee.

EXAMPLE — BLESS

Bless:

CONCENTRATION, UP TO 1 MINUTE

It could last:

1 ROUND

5 ROUNDS

10 ROUNDS

or less,

depending on whether Concentration continues and whether another rule ends the spell.

PART TWENTY — ONE MINUTE IS ABOUT TEN ROUNDS

A combat round is about:

6 SECONDS

Therefore:

60 seconds ÷ 6 =

ABOUT 10 ROUNDS

So:

CONCENTRATION, UP TO 1 MINUTE

can potentially cover approximately:

TEN COMBAT ROUNDS

if nothing ends the Concentration earlier.

This is a derived time conversion from the combat-round rule.

PART TWENTY-ONE — HEX

Hex begins with:

CONCENTRATION, UP TO 1 HOUR

At higher slot levels, its maximum Concentration duration can increase to:

4 HOURS

8 HOURS

or:

24 HOURS

depending on the slot used.

The spell still requires:

CONCENTRATION

during those extended durations.

PART TWENTY-TWO — SHIELD OF FAITH

Shield of Faith:

CONCENTRATION, UP TO 10 MINUTES

and provides:

+2 AC

to its target while active.

If the caster loses Concentration:

THE +2 AC ENDS

even if only ten seconds have passed.

PART TWENTY-THREE — CONCENTRATION IS A RESOURCE

A Spell Slot is:

ONE RESOURCE

Your Action economy is:

ANOTHER RESOURCE

Concentration is effectively:

ANOTHER LIMITATION

You have only one active Concentration effect at a time because starting another one:

ENDS THE FIRST

PART TWENTY-FOUR — YOU CAN DO OTHER THINGS WHILE CONCENTRATING

Concentration does not mean:

"YOU MUST SPEND YOUR ACTION EVERY TURN TO KEEP THE SPELL ACTIVE"

Once a normal Concentration spell is cast, maintaining it doesn't normally require:

AN ACTION

A BONUS ACTION

or:

A REACTION

The rules instead tell you what events:

BREAK CONCENTRATION

EXAMPLE

Cleric casts:

BLESS

Then on later turns the Cleric can:

MOVE

ATTACK

CAST OTHER NON-CONCENTRATION SPELLS

TAKE OTHER ACTIONS

while still maintaining:

BLESS

provided none of those actions starts another Concentration effect or otherwise breaks Concentration.

PART TWENTY-FIVE — CONCENTRATION DOES NOT REQUIRE STANDING STILL

The Concentration rule does not say you must remain:

MOTIONLESS

You can:

MOVE

while concentrating.

You can climb, run, ride, or otherwise move according to normal movement rules unless:

ANOTHER RULE

says otherwise.

PART TWENTY-SIX — CONCENTRATION DOES NOT PREVENT ATTACKING

You can maintain a Concentration spell and:

MAKE WEAPON ATTACKS

or:

MAKE SPELL ATTACKS

with other spells that don't require Concentration.

The key is:

DON'T START ANOTHER CONCENTRATION EFFECT

PART TWENTY-SEVEN — CONCENTRATION DOES NOT PREVENT CASTING OTHER SPELLS

This is another huge beginner misunderstanding.

While concentrating on:

BLESS

you may cast:

CURE WOUNDS

because Cure Wounds does not require Concentration.

You may cast:

FIRE BOLT

because Fire Bolt does not require Concentration.

But if you begin casting another spell that:

DOES REQUIRE CONCENTRATION

Bless ends.

PART TWENTY-EIGHT — THE THREE GENERAL WAYS CONCENTRATION BREAKS

The Rules Glossary lists three factors:

1. ANOTHER CONCENTRATION EFFECT

2. DAMAGE

3. INCAPACITATED OR DEAD

We will study each.

PART TWENTY-NINE — BREAKER ONE: ANOTHER CONCENTRATION EFFECT

You lose Concentration on the current effect:

THE MOMENT

you:

START CASTING ANOTHER SPELL THAT REQUIRES CONCENTRATION

or:

ACTIVATE ANOTHER EFFECT THAT REQUIRES CONCENTRATION

IMPORTANT WORD

START

You do not wait until:

THE SECOND SPELL IS FINISHED

Your old Concentration ends:

WHEN YOU START THE NEW CONCENTRATION EFFECT

PART THIRTY — BLESS TO SHIELD OF FAITH

Cleric is concentrating on:

BLESS

Then begins casting:

SHIELD OF FAITH

Shield of Faith requires:

CONCENTRATION

Result:

BLESS ENDS IMMEDIATELY

The Cleric's Concentration shifts to:

SHIELD OF FAITH

if the new spell is successfully established.

PART THIRTY-ONE — YOU DON'T GET A CONCENTRATION SAVE TO KEEP THE OLD ONE

This is not:

A CONSTITUTION SAVE

There is no roll.

Starting another Concentration effect:

AUTOMATICALLY ENDS THE FIRST

PART THIRTY-TWO — YOU CAN'T CHOOSE TO CONCENTRATE ON TWO

The player cannot say:

"I'M REALLY FOCUSED, SO I'LL MAINTAIN BLESS AND SHIELD OF FAITH."

Under the normal rules:

NO

The limit comes from the Concentration rule itself.

PART THIRTY-THREE — IT APPLIES TO NON-SPELL CONCENTRATION EFFECTS TOO

The rule isn't limited to:

SPELL + SPELL

It says you also lose Concentration when you activate:

ANOTHER EFFECT THAT REQUIRES CONCENTRATION

So:

SPELL CONCENTRATION

and:

FEATURE CONCENTRATION

share the same limitation when those effects use the Concentration rule.

PART THIRTY-FOUR — LONGER CASTING TIMES ALSO REQUIRE CONCENTRATION

Recall Lesson 73.

If a spell's Casting Time is:

1 MINUTE OR MORE

you must maintain:

CONCENTRATION

while casting it.

Therefore, if you're already concentrating on Bless and begin a:

1-MINUTE SPELL

that casting requires Concentration.

Your Bless therefore ends when the new Concentration requirement begins.

PART THIRTY-FIVE — RITUALS CAN ALSO BREAK EXISTING CONCENTRATION

A Ritual takes:

10 MINUTES LONGER

than normal.

That gives it a Casting Time of at least:

10 MINUTES

beyond the original time.

Long Casting rules therefore require:

CONCENTRATION DURING THE RITUAL CASTING

So beginning the Ritual can end:

YOUR EXISTING CONCENTRATION EFFECT

PART THIRTY-SIX — BREAKER TWO: DAMAGE

When a creature maintaining Concentration takes damage:

MAKE A CONSTITUTION SAVING THROW

to maintain Concentration.

This is commonly called:

A CONCENTRATION SAVE

But mechanically it is:

A CONSTITUTION SAVING THROW

PART THIRTY-SEVEN — CONCENTRATION SAVE DC

The DC is:

10

or:

HALF THE DAMAGE TAKEN, ROUNDED DOWN

whichever is:

HIGHER

And the DC can never exceed:

30

Formula:

DC = MAXIMUM OF 10 OR FLOOR(DAMAGE ÷ 2), CAPPED AT 30

19

Half:

19 ÷ 2 =

9

rounded down.

DC:

10 PART THIRTY-NINE — TWENTY DAMAGE

Damage:

20

Half:

10

Compare with 10:

DC 10

PART FORTY — TWENTY-ONE DAMAGE

Damage:

21

Half:

10.5

Round down:

10

DC:

10 PART FORTY-ONE — TWENTY-TWO DAMAGE

Damage:

22

Half:

11

DC 50

COMPLETE REFERENCE TABLE

Damage Taken	Half, Rounded Down	Concentration DC
1	0	10
10	5	10
19	9	10
20	10	10
21	10	10
22	11	11
30	15	15
40	20	20
50	25	25
60	30	30
100	50	30 maximum

PART FORTY-SIX — PASS THE SAVE

If you succeed:

CONCENTRATION CONTINUES

The spell remains active, assuming nothing else ends it.

FAIL THE SAVE

If you fail:

CONCENTRATION ENDS

Therefore:

THE CONCENTRATION EFFECT ENDS

PART FORTY-SEVEN — THE DAMAGE STILL HAPPENS

Passing the Concentration save does not:

REDUCE THE DAMAGE

The save is only asking:

DID YOU MAINTAIN CONCENTRATION?

You already took the damage.

EXAMPLE

Wizard concentrating on:

INVISIBILITY

takes:

14 DAMAGE

Concentration DC:

10

Wizard succeeds.

Result:

Wizard takes:

ALL 14 DAMAGE

but:

CONCENTRATION REMAINS

unless another rule affects the spell.

PART FORTY-EIGHT — CONSTITUTION SAVE BONUSES APPLY NORMALLY

Because the Concentration check is a:

CONSTITUTION SAVING THROW

use the character's normal:

CONSTITUTION SAVE MODIFIER

That can include:

CONSTITUTION MODIFIER

PROFICIENCY BONUS

if proficient in Constitution saving throws,

and other bonuses that apply to:

SAVING THROWS

EXAMPLE

Constitution:

16

Modifier:

+3

Character is proficient in Constitution saves.

PB:

+3

Constitution Saving Throw modifier:

3 + 3 =

+6

Damage:

24

Concentration DC:

24 ÷ 2 =

12

Roll:

d20: 9

Modifier:

Total:

15

15 ≥ 12.

CONCENTRATION MAINTAINED

PART FORTY-NINE — EACH TIME DAMAGE REQUIRES THE RULE, CHECK AGAIN

The rule triggers:

IF YOU TAKE DAMAGE

So being damaged repeatedly can force:

REPEATED CONSTITUTION SAVING THROWS

EXAMPLE

You are concentrating on Bless.

Enemy A hits you:

8 DAMAGE

DC:

10

Save.

Enemy B later hits you:

12 DAMAGE

DC:

10

Save again.

Enemy C hits you:

32 DAMAGE

DC:

16

Save again.

Each damaging event can threaten:

THE SAME CONCENTRATION EFFECT

until it ends.

PART FIFTY — MULTIPLE ATTACKS CAN BE VERY DANGEROUS TO CONCENTRATION

This is gameplay application.

A giant single hit might create:

ONE HARD SAVE

Several smaller hits can create:

MULTIPLE DC 10 SAVES

Even when each individual DC is modest, repeated rolls increase the chance that:

ONE EVENTUALLY FAILS

That is one reason Concentration casters often care about:

POSITIONING

COVER

ARMOR CLASS

and:

DEFENSIVE MAGIC

PART FIFTY-ONE — TEMPORARY HIT POINTS DO NOT CREATE A SPECIAL CONCENTRATION EXCEPTION

The Concentration rule asks whether:

YOU TAKE DAMAGE

Temporary Hit Points use their normal damage rules.

Do not invent a special general rule saying:

"DAMAGE TO TEMP HP NEVER COUNTS"

unless another rule specifically says so.

Apply the actual damage and Concentration rules to the event.

PART FIFTY-TWO — BREAKER THREE: INCAPACITATED

Your Concentration ends if:

YOU HAVE THE INCAPACITATED CONDITION

No save.

No damage required.

Result:

CONCENTRATION ENDS

PART FIFTY-THREE — INCAPACITATED DOESN'T GIVE YOU A SAVE TO HOLD THE SPELL

Suppose you're concentrating on:

HEX

An effect gives you:

INCAPACITATED

Result:

HEX ENDS

You don't roll:

A CONSTITUTION SAVE

The condition itself ends Concentration.

PART FIFTY-FOUR — DEAD

Concentration also ends if:

YOU DIE

This is automatic.

PART FIFTY-FIVE — 0 HP AND DEATH ARE NOT THE SAME THING

Be careful with terminology.

The Concentration rule specifically says:

INCAPACITATED OR DEAD

It doesn't separately say:

"0 HIT POINTS"

condition in their effects.

Therefore they can also end:

CONCENTRATION

through that connection.

The precise condition rules will be studied comprehensively in Lessons 86–90.

PART FIFTY-EIGHT — YOU MAY END CONCENTRATION VOLUNTARILY

The creator of a Concentration effect can end Concentration:

AT ANY TIME

requiring:

NO ACTION

EXAMPLE

You are maintaining:

WALL OF FIRE

An ally is about to be forced through it.

You decide:

END CONCENTRATION

No Action required.

The Concentration effect ends immediately according to its rules.

PART FIFTY-NINE — YOU DON'T NEED TO WAIT FOR YOUR TURN

The rule says:

AT ANY TIME

not:

ONLY ON YOUR TURN

So voluntary ending isn't limited to:

YOUR ACTION PHASE

No Reaction is required.

PART SIXTY — ENDING CONCENTRATION DOES NOT REFUND THE SPELL SLOT

You already cast the spell.

Ending Concentration early does not:

RETURN THE SPELL SLOT

The spell has simply:

ENDED EARLY

PART SIXTY-ONE — MAXIMUM DURATION IS NOT MANDATORY

Suppose Hex can last:

UP TO 1 HOUR

You do not have to maintain it for:

THE FULL HOUR

You may voluntarily stop:

TARGET SUCCEEDS ON ITS SAVE

or:

MAXIMUM DURATION EXPIRES

Different ending mechanisms can coexist.

PART SIXTY-FOUR — CONCENTRATION AND DISTANCE

The general Concentration rule does not say:

"CONCENTRATION AUTOMATICALLY ENDS WHEN THE TARGET LEAVES THE ORIGINAL SPELL RANGE."

Whether distance matters after casting is determined by:

THE SPELL'S SPECIFIC DESCRIPTION

and the general Range rules studied in Lesson 74.

Do not invent a universal:

"MUST STAY WITHIN RANGE TO MAINTAIN CONCENTRATION"

rule.

PART SIXTY-FIVE — CONCENTRATION AND LINE OF SIGHT

Similarly, the general Concentration rule does not say:

"YOU MUST KEEP SEEING THE TARGET."

Some spells might impose their own continuing requirements.

But:

CONCENTRATION ITSELF

doesn't universally require:

LINE OF SIGHT

after the spell is already cast.

PART SIXTY-SIX — CONCENTRATION AND VERBAL/SOMATIC COMPONENTS

After you have cast the spell, maintaining Concentration does not generally require you to keep:

SPEAKING THE VERBAL COMPONENT

or:

REPEATING THE SOMATIC COMPONENT

Components are requirements for:

CASTING THE SPELL

Concentration has:

ITS OWN MAINTENANCE RULES

PART SIXTY-SEVEN — SILENCE AFTER CASTING

Suppose a Cleric casts:

BLESS

Then later enters:

MAGICAL SILENCE

Bless does not automatically end merely because:

VERBAL COMPONENTS CAN'T NOW BE SPOKEN

The Verbal component was needed when:

CASTING BLESS

Maintaining Concentration is governed by:

THE CONCENTRATION RULES

unless another rule specifically changes the situation.

PART SIXTY-EIGHT — LOSING YOUR FOCUS AFTER CASTING

Suppose a Wizard uses an Arcane Focus to cast a Concentration spell.

After casting, the focus is knocked from their hand.

Does Concentration automatically end?

NOT UNDER THE GENERAL CONCENTRATION RULE

The focus was needed to satisfy the Material component:

DURING CASTING

Concentration afterward is governed by:

ITS OWN RULES

unless the spell says otherwise.

PART SIXTY-NINE — READYING A SPELL REQUIRES CONCENTRATION

When you use:

READY

to Ready a spell, you actually cast the spell on your turn, spending any resources normally.

Then you:

HOLD ITS ENERGY

Holding that spell requires:

CONCENTRATION

and can last until:

THE START OF YOUR NEXT TURN

PART SEVENTY — READYING A SPELL BREAKS AN EXISTING CONCENTRATION EFFECT

Suppose you are concentrating on:

BLESS

Then you Ready:

FIRE BOLT

Fire Bolt itself isn't normally a Concentration spell.

But:

HOLDING A READIED SPELL REQUIRES CONCENTRATION

Therefore:

YOU CANNOT MAINTAIN BLESS AT THE SAME TIME

Your old Concentration must end when the new Concentration requirement begins.

PART SEVENTY-ONE — READIED SPELL TAKES DAMAGE

You Ready Fire Bolt.

Before the trigger occurs:

AN ENEMY HITS YOU

You are concentrating on:

HOLDING THE SPELL'S ENERGY

So the damage triggers:

A CONSTITUTION SAVING THROW

If you fail:

CONCENTRATION BREAKS

and:

THE READIED SPELL DISSIPATES WITHOUT TAKING EFFECT

PART SEVENTY-TWO — THE READIED SPELL'S RESOURCE IS ALREADY SPENT

Remember Lesson 73.

When you Ready a spell:

YOU CAST IT NOW

Therefore if the held spell dissipates:

THE SPELL SLOT IS NOT REFUNDED

The resource had already been expended during:

THE READY ACTION

PART SEVENTY-THREE — LONG CASTING IS DIFFERENT

A spell with Casting Time:

1 MINUTE OR MORE

also requires Concentration during casting.

But if that Concentration is broken before completion:

THE SPELL FAILS

and:

YOU DON'T EXPEND THE SPELL SLOT

COMPARE

READIED SPELL

Already cast.

Resource:

ALREADY EXPENDED

Lose Concentration:

SPELL DISSIPATES

LONG CASTING

Not yet completed.

Lose Concentration:

SPELL FAILS

Resource:

SPELL SLOT NOT EXPENDED

PART SEVENTY-FOUR — RITUAL CASTING AND CONCENTRATION

A Ritual takes:

10 MINUTES LONGER

than normal.

Because it therefore has a long Casting Time:

MAINTAIN CONCENTRATION DURING CASTING

according to the Longer Casting Times rule.

EXAMPLE

Wizard is concentrating on:

INVISIBILITY

Then begins casting:

A RITUAL

The Ritual's long casting requires:

CONCENTRATION

Therefore the Wizard cannot continue concentrating on:

INVISIBILITY

at the same time.

PART SEVENTY-FIVE — A SPELL MAY REMOVE ITS OWN CONCENTRATION AT HIGHER LEVEL

Specific spells can modify their own Duration.

An excellent example is:

BESTOW CURSE

At its normal level:

CONCENTRATION, UP TO 1 MINUTE

With a level 4 slot:

UP TO 10 MINUTES OF CONCENTRATION

With a level 5 or higher slot:

THE SPELL CAN STOP REQUIRING CONCENTRATION

and its duration changes according to the spell.

PART SEVENTY-SIX — BESTOW CURSE IS A PERFECT SPECIFIC-RULE EXAMPLE

Base level 3:

CONCENTRATION, UP TO 1 MINUTE

Level 4 slot:

CONCENTRATION, UP TO 10 MINUTES

Level 5–6 slot:

NO CONCENTRATION

8 HOURS

Level 7–8 slot:

NO CONCENTRATION

24 HOURS

Level 9 slot:

LASTS UNTIL DISPELLED

This demonstrates that:

Whenever you learn a spell, look at:

DURATION

and immediately ask:

INSTANTANEOUS?

Resolve it and the spell's magic is:

DONE

TIME SPAN?

Record:

WHEN IT ENDS

and check for:

EARLY-END CONDITIONS

CONCENTRATION?

Mark clearly:

CONCENTRATING

and remember:

DON'T START ANOTHER CONCENTRATION EFFECT UNLESS YOU WANT THIS ONE TO END

PART EIGHTY-ONE — AT THE TABLE: TRACKING CONCENTRATION

When you cast:

BLESS

place a visible marker on your sheet:

CONCENTRATION — BLESS

This can be:

A TOKEN

A CHECKBOX

A COIN

A DIGITAL MARKER

The method isn't a game rule.

It is a practical technique to prevent:

ACCIDENTAL DOUBLE CONCENTRATION

PART EIGHTY-TWO — WHEN DAMAGE HAPPENS

Immediately ask:

AM I CONCENTRATING?

If no:

NO CONCENTRATION SAVE

If yes:

CALCULATE THE DC

STEP 1

Take damage.

STEP 2

Divide damage by:

2

Round:

DOWN

STEP 3

Compare with:

10

Take:

THE HIGHER NUMBER

STEP 4

Cap at:

DC 30

STEP 5

Roll:

CONSTITUTION SAVING THROW

STEP 6

Success:

KEEP CONCENTRATING

Failure:

EFFECT ENDS

PART EIGHTY-THREE — COMPLETE COMBAT EXAMPLE

Cleric casts:

BLESS

Duration:

CONCENTRATION, UP TO 1 MINUTE

ROUND 1

Cleric casts Bless.

Concentration:

ACTIVE

ENEMY TURN

Goblin hits Cleric for:

7 DAMAGE

Half:

3

DC:

10

Cleric rolls:

d20: 12

Constitution Save modifier:

Total:

14

Success.

Bless:

CONTINUES

ROUND 2

Cleric casts:

CURE WOUNDS

Cure Wounds doesn't require Concentration.

Does Bless end?

NO

Bless continues.

NEXT ENEMY

Ogre hits Cleric for:

28 DAMAGE

Half:

14

DC:

14

Cleric rolls:

d20: 8

Modifier:

Total:

10

Failure.

Result:

BLESS ENDS

PART EIGHTY-FOUR — COMPLETE DOUBLE-CONCENTRATION EXAMPLE

Cleric is concentrating on:

BLESS

Then chooses to cast:

SHIELD OF FAITH

Does the Cleric roll to decide which one survives?

NO

The moment the Cleric starts casting Shield of Faith:

BLESS ENDS

Shield of Faith becomes the new Concentration effect when established.

PART EIGHTY-FIVE — COMPLETE INVISIBILITY EXAMPLE

Wizard casts:

INVISIBILITY

Duration:

CONCENTRATION, UP TO 1 HOUR

The target remains Invisible.

Wizard later takes:

6 DAMAGE

Concentration DC:

10

Wizard succeeds.

Spell continues.

Then the invisible target:

MAKES AN ATTACK ROLL

Invisibility says it ends early:

IMMEDIATELY

after that occurs.

Even though the Wizard never lost Concentration:

THE SPELL ENDS

because the spell itself provides:

AN EARLY-END CONDITION

PART EIGHTY-SIX — COMPLETE NON-CONCENTRATION EXAMPLE

Wizard casts:

MAGE ARMOR

Duration:

8 HOURS

Wizard takes:

40 DAMAGE

Does the Wizard make a Concentration save for Mage Armor?

NO

Mage Armor isn't:

A CONCENTRATION SPELL

The damage doesn't threaten it through the Concentration rule.

Later the target puts on:

ARMOR

What happens?

MAGE ARMOR ENDS EARLY

because:

THE SPELL SAYS SO

PART EIGHTY-SEVEN — CONCENTRATION AS A TACTICAL CHOICE

Suppose a Paladin can choose between:

BLESS

and:

SHIELD OF FAITH

Both require:

CONCENTRATION

The Paladin cannot maintain both normally.

So the question becomes:

WHICH EFFECT IS MORE VALUABLE RIGHT NOW?

Bless:

MULTIPLE CREATURES

and helps certain rolls.

Shield of Faith:

+2 AC

for one creature.

The rules force:

A CHOICE

That is one of Concentration's main gameplay purposes.

PART EIGHTY-EIGHT — PROTECTING CONCENTRATION

This is tactical interpretation based on the rules.

A character relying on an important Concentration spell can improve its chances of surviving by:

AVOIDING DAMAGE

IMPROVING AC

STAYING BEHIND ALLIES

USING COVER

INCREASING CONSTITUTION SAVE BONUSES

or otherwise reducing:

HOW OFTEN THEY MUST MAKE CONCENTRATION SAVES

The Concentration rule turns defense into:

SPELL MAINTENANCE

PART EIGHTY-NINE — A POWERFUL SPELL CAN BE WORTH PROTECTING

Suppose a Wizard has one spell controlling:

THREE ENEMIES

If Concentration breaks:

ALL OF THAT CONTROL MAY END

So enemies may have strong tactical reason to:

ATTACK THE CASTER

while allies may have strong reason to:

PROTECT THE CASTER

This creates dynamic battlefield decisions without requiring:

ANY ADDITIONAL RULE

COMMON BEGINNER MISTAKES

MISTAKE 1 — CONFUSING CASTING TIME AND DURATION

Casting Time:

HOW LONG TO CAST

Duration:

HOW LONG EFFECT LASTS

MISTAKE 2 — THINKING INSTANTANEOUS MEANS THE SPELL DID NOTHING LASTING

Instantaneous magic can create:

LASTING CONSEQUENCES

if the spell says so.

MISTAKE 3 — TRYING TO BREAK CONCENTRATION ON FIREBALL AFTER IT EXPLODES

Fireball is:

INSTANTANEOUS

There is no ongoing Fireball Concentration.

MISTAKE 4 — THINKING EVERY ONGOING SPELL REQUIRES CONCENTRATION

No.

Mage Armor:

8 HOURS

No Concentration.

Longstrider:

1 HOUR

No Concentration.

Mirror Image:

1 MINUTE

No Concentration.

MISTAKE 5 — MAKING CONCENTRATION SAVES FOR MAGE ARMOR

No.

It doesn't require Concentration.

MISTAKE 6 — THINKING A TIME-SPAN SPELL MUST LAST THE FULL TIME

Spell-specific rules can:

END IT EARLY

MISTAKE 7 — THINKING YOU CAN'T DISMISS YOUR OWN TIME-SPAN SPELL

The general rule allows dismissal:

NO ACTION REQUIRED

while it is ongoing, if you aren't:

INCAPACITATED

MISTAKE 8 — THINKING CONCENTRATION REQUIRES YOUR ACTION EVERY TURN

Normal ongoing Concentration:

DOES NOT

Long Casting is a different rule.

MISTAKE 9 — THINKING CONCENTRATION MEANS YOU CAN'T MOVE

You can normally:

MOVE

MISTAKE 10 — THINKING CONCENTRATION MEANS YOU CAN'T ATTACK

You can attack.

MISTAKE 11 — THINKING CONCENTRATION MEANS YOU CAN'T CAST ANY OTHER SPELL

You can cast spells that don't start:

ANOTHER CONCENTRATION EFFECT

subject to normal spellcasting rules.

MISTAKE 12 — CASTING BLESS AND SHIELD OF FAITH TOGETHER WITH ONE CASTER

Both require:

CONCENTRATION

Starting the second ends:

THE FIRST

MISTAKE 13 — THINKING YOU GET A SAVE TO MAINTAIN TWO CONCENTRATION EFFECTS

No.

The first ends:

AUTOMATICALLY

MISTAKE 14 — WAITING UNTIL THE SECOND CONCENTRATION SPELL RESOLVES BEFORE ENDING THE FIRST

The rule says:

THE MOMENT YOU START CASTING

the second Concentration spell.

MISTAKE 15 — THINKING ONLY SPELLS COMPETE FOR CONCENTRATION

Other effects that require:

CONCENTRATION

also compete.

MISTAKE 16 — FORGETTING LONG CASTINGS REQUIRE CONCENTRATION

Casting Time:

1 MINUTE OR MORE

requires:

CONCENTRATION DURING CASTING

MISTAKE 17 — FORGETTING RITUALS REQUIRE CONCENTRATION DURING THEIR LONG CASTING

They fall under:

LONGER CASTING TIMES

MISTAKE 18 — USING AN ABILITY CHECK FOR DAMAGE CONCENTRATION

It's a:

CONSTITUTION SAVING THROW

MISTAKE 19 — ALWAYS USING DC 10

DC is:

10 OR HALF DAMAGE

whichever is:

HIGHER

MISTAKE 20 — FORGETTING TO ROUND HALF DAMAGE DOWN

Damage:

21

Half:

10

not:

11

MISTAKE 21 — THINKING 20 DAMAGE CREATES DC 20

It creates:

DC 10

Half of 20:

10

MISTAKE 22 — THINKING 30 DAMAGE CREATES DC 30

Half:

15

Therefore:

DC 15

MISTAKE 23 — THINKING 100 DAMAGE CREATES DC 50

Maximum DC:

30

MISTAKE 24 — THINKING PASSING THE CONCENTRATION SAVE REDUCES DAMAGE

It doesn't.

It only maintains:

CONCENTRATION

MISTAKE 25 — MAKING ONLY ONE SAVE FOR AN ENTIRE FIGHT

Every damaging event that triggers the rule can threaten:

CONCENTRATION AGAIN

MISTAKE 26 — THINKING INCAPACITATED GIVES A CONCENTRATION SAVE

No.

Concentration:

ENDS AUTOMATICALLY

MISTAKE 27 — THINKING DEATH ALLOWS CONCENTRATION TO CONTINUE

No.

Death:

ENDS CONCENTRATION

MISTAKE 28 — FORGETTING THAT UNCONSCIOUS INCLUDES INCAPACITATED

Therefore it ends:

CONCENTRATION

through the condition rules.

MISTAKE 29 — THINKING YOU NEED AN ACTION TO VOLUNTARILY END CONCENTRATION

No action required.

MISTAKE 30 — THINKING YOU MUST WAIT UNTIL YOUR TURN TO END CONCENTRATION

The rule says:

AT ANY TIME

MISTAKE 31 — THINKING ENDING CONCENTRATION RETURNS THE SPELL SLOT

It doesn't.

MISTAKE 32 — ASSUMING CONCENTRATION CONTINUES AUTOMATICALLY UNTIL MAXIMUM DURATION

"Up to" means:

MAXIMUM

Many things can end it earlier.

MISTAKE 33 — THINKING LOSING SIGHT OF THE TARGET AUTOMATICALLY BREAKS EVERY CONCENTRATION SPELL

Not a universal Concentration rule.

Read:

THE SPECIFIC SPELL

MISTAKE 34 — THINKING THE TARGET LEAVING ORIGINAL RANGE AUTOMATICALLY ENDS EVERY CONCENTRATION SPELL

Not a universal rule.

Read:

THE SPECIFIC SPELL

MISTAKE 35 — THINKING YOU MUST KEEP SPEAKING V COMPONENTS TO MAINTAIN CONCENTRATION

Components belong to:

CASTING

Concentration uses:

ITS OWN RULES

MISTAKE 36 — THINKING YOU MUST KEEP HOLDING THE FOCUS FOREVER

Not under the general Concentration rule.

The focus was used for:

CASTING

unless the spell specifically requires something more.

MISTAKE 37 — FORGETTING READYING A SPELL REQUIRES CONCENTRATION

Holding the Readied spell:

REQUIRES CONCENTRATION

MISTAKE 38 — THINKING YOU CAN READY A SPELL WHILE MAINTAINING ANOTHER CONCENTRATION EFFECT

Normally no.

Holding the Readied spell itself requires:

CONCENTRATION

MISTAKE 39 — REFUNDING A LOST READIED SPELL SLOT

The spell was already cast when:

READIED

MISTAKE 40 — SPENDING THE SLOT WHEN A LONG CASTING FAILS FROM BROKEN CONCENTRATION

The Longer Casting rule specifically says:

NO SPELL SLOT IS EXPENDED

MISTAKE 41 — THINKING UPCASTING ALWAYS EXTENDS DURATION

Only when:

THE SPELL SAYS SO

MISTAKE 42 — THINKING EVERY HIGHER-LEVEL BESTOW CURSE STILL REQUIRES CONCENTRATION

Bestow Curse specifically removes Concentration at:

LEVEL 5+ SLOTS

under its higher-level rules.

QUICK RECAP

DURATION

How long a spell persists:

AFTER CASTING

INSTANTANEOUS

Magic appears:

FOR A MOMENT

then:

DISAPPEARS

But its consequences may:

PERSIST

TIME SPAN

Examples:

1 ROUND

1 MINUTE

1 HOUR

8 HOURS

Spell-specific rules can end it:

EARLY

DISMISSAL

An ongoing Time-Span spell you cast can generally be dismissed:

NO ACTION REQUIRED

if you are not:

INCAPACITATED

CONCENTRATION

If you lose Concentration:

EFFECT ENDS

Maximum duration might be:

UP TO 1 MINUTE

UP TO 1 HOUR

etc.

END CONCENTRATION VOLUNTARILY

ANY TIME

NO ACTION

BREAKER 1

Start:

ANOTHER CONCENTRATION SPELL

or activate another:

CONCENTRATION EFFECT

Result:

FIRST CONCENTRATION ENDS

BREAKER 2

Take:

DAMAGE

Roll:

CONSTITUTION SAVING THROW

DC:

10 OR HALF DAMAGE, ROUND DOWN

whichever is higher.

Maximum:

DC 30

BREAKER 3

Become:

INCAPACITATED

or:

DIE

Result:

CONCENTRATION ENDS AUTOMATICALLY

LONG CASTING

Casting Time:

1 MINUTE OR MORE

Requires:

MAGIC ACTION EACH TURN

and:

CONCENTRATION

If broken:

SPELL FAILS

SLOT NOT EXPENDED

START OVER

READY SPELL

Holding it requires:

CONCENTRATION

If broken:

SPELL DISSIPATES

but:

RESOURCES WERE ALREADY EXPENDED

PRIME HERO CHALLENGE

A Cleric is concentrating on:

BLESS

Duration:

UP TO 1 MINUTE

The Cleric has:

CONSTITUTION SAVE +4

SCENARIO 1

Cleric takes:

9 DAMAGE

Half:

4

Concentration DC:

10

Roll:

d20: 8

Modifier:

Total:

12

Result:

CONCENTRATION MAINTAINED

SCENARIO 2

Later the Cleric takes:

34 DAMAGE

Half:

17

DC:

17

Roll:

d20: 12

Modifier:

Total:

16

Result:

FAILURE

Bless:

ENDS

SCENARIO 3

Reset the situation.

Cleric is concentrating on Bless and has taken:

NO DAMAGE

They begin casting:

SHIELD OF FAITH

What happens to Bless?

IT ENDS IMMEDIATELY

No save is rolled.

Why?

Shield of Faith also requires:

CONCENTRATION

SCENARIO 4

Cleric is concentrating on Bless.

They cast:

CURE WOUNDS

which doesn't require Concentration.

Does Bless end?

Mage Armor:

DOESN'T REQUIRE CONCENTRATION

Later the target dons armor.

What happens?

MAGE ARMOR ENDS

because its own spell description says so.

READY CHALLENGE

Wizard is concentrating on:

INVISIBILITY

Then uses Ready to hold:

FIRE BOLT

Does Fire Bolt normally require Concentration?

NO

But does holding a Readied Fire Bolt require Concentration?

YES

Therefore what happens to Invisibility?

IT ENDS

because the Wizard begins another:

CONCENTRATION EFFECT

The Wizard takes:

18 DAMAGE

while holding the Readied spell.

Concentration DC:

10

because half of 18 is:

9

The Wizard fails.

What happens?

FIRE BOLT DISSIPATES

Does the spent resource return?

Fire Bolt is a Cantrip, so no Spell Slot was spent, but in general:

RESOURCES USED TO READY A SPELL ARE NOT REFUNDED

LONG CASTING CHALLENGE

A spell has:

CASTING TIME: 1 MINUTE

After eight rounds of casting, the caster takes:

40 DAMAGE

Concentration DC:

40 ÷ 2 =

20

The caster fails.

Result:

SPELL FAILS

Spell Slot:

NOT EXPENDED

Progress:

LOST

To try again:

START OVER

FINAL CONCENTRATION CHALLENGE

Calculate the Concentration DC for each hit:

6 damage

DC 10

19 damage

DC 10

21 damage

Half rounded down:

10

Therefore:

DC 10

22 damage

Half:

11

Therefore:

DC 11

48 damage

Half:

24

Therefore:

DC 24

80 damage

Half:

40

But maximum:

DC 30

If you can calculate those quickly at the table:

YOU UNDERSTAND THE CORE CONCENTRATION SAVE RULE

LESSON 77 — KEY TAKEAWAYS

Spell Duration answers:

HOW LONG DOES THIS MAGIC REMAIN?

But you must distinguish:

INSTANTANEOUS

TIME SPAN

and:

CONCENTRATION

Instantaneous magic exists:

ONLY MOMENTARILY

but can still cause:

LASTING CONSEQUENCES

Time-Span effects persist for their listed time unless:

THE SPELL ENDS EARLY

or:

ANOTHER RULE ENDS THEM

And your own ongoing Time-Span spell can generally be dismissed:

WITHOUT AN ACTION

if you aren't Incapacitated.

Concentration creates a much more active limitation.

The spell remains only while:

YOU MAINTAIN CONCENTRATION

You can:

MOVE

ATTACK

CAST NON-CONCENTRATION SPELLS

and:

ACT NORMALLY

But three fundamental threats remain:

START ANOTHER CONCENTRATION EFFECT

TAKE DAMAGE AND FAIL THE CONSTITUTION SAVE

or:

BECOME INCAPACITATED / DIE

The damage formula is:

DC 10 OR HALF DAMAGE, ROUND DOWN

WHICHEVER IS HIGHER

MAXIMUM DC 30

And the most important strategic rule is:

ONE CONCENTRATION EFFECT AT A TIME

This means choosing a Concentration spell isn't only choosing:

WHAT SPELL TO CAST

It is choosing:

WHAT MAGICAL EFFECT DESERVES YOUR ATTENTION RIGHT NOW

That choice is one of the central tactical decisions for advanced spellcasters.

NEXT LESSON

LESSON 78 — SPELL SAVING THROWS, SPELL ATTACKS, INVALID TARGETS, AND COMBINING MAGICAL EFFECTS

We have now covered:

SPELL ACCESS

SPELL SLOTS

CASTING TIME

RANGE

TARGETS

COMPONENTS

DURATION

and:

CONCENTRATION

The final general spellcasting lesson will explain exactly how spells:

SUCCEED OR FAIL AGAINST TARGETS

We will cover:

SPELL SAVE DC

SPELLCASTING ABILITY

SPELL ATTACK MODIFIER

RANGED SPELL ATTACKS

MELEE SPELL ATTACKS

NATURAL 20

NATURAL 1

ADVANTAGE AND DISADVANTAGE

INVALID TARGETS

and the crucial rule for:

COMBINING SPELL EFFECTS

including what happens when:

TWO CREATURES CAST THE SAME SPELL ON THE SAME TARGET

and why magical bonuses don't always:

STACK

After that, Lesson 79 begins the complete:

SPELL COMPENDIUM A–B

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.

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Secret Lesson 77

Spell Duration and Concentration: Instantaneous Magic, Time-Span Effects, Maintaining Spells, Taking Damage, and Losing Concentration

WHICH SPELLS YOU CAN CAST

WHAT SPELL SLOTS POWER THEM

WHEN YOU CAN CAST THEM

WHERE THEY CAN REACH

WHAT COMPONENTS THEY REQUIRE

HOW LONG DOES THE MAGIC LAST?

A SINGLE MOMENT

ONE ROUND

ONE MINUTE

TEN MINUTES

ONE HOUR

EIGHT HOURS

UNTIL DISPELLED

CONCENTRATION

YOU CAN'T MAINTAIN MULTIPLE CONCENTRATION EFFECTS AT ONCE

THE FIRST ENDS

BREAK YOUR CONCENTRATION

PART ONE — WHAT IS SPELL DURATION?

DURATION

AFTER IT IS CAST

CONCENTRATION

INSTANTANEOUS

TIME SPAN

PART TWO — THE THREE BASIC DURATION TYPES

1. INSTANTANEOUS

FOR A MOMENT

DISAPPEARS

2. TIME SPAN

1 ROUND

1 MINUTE

1 HOUR

8 HOURS

3. CONCENTRATION

MAINTAINS CONCENTRATION

PART THREE — DURATION IS NOT CASTING TIME

CASTING TIME

HOW LONG IT TAKES TO CAST THE SPELL

DURATION

HOW LONG THE EFFECT PERSISTS AFTER CASTING

EXAMPLE — SHIELD

REACTION

1 ROUND

ALMOST INSTANTLY AS A REACTION

THE START OF YOUR NEXT TURN

EXAMPLE — MAGIC CIRCLE

1 MINUTE

1 HOUR

ONE MINUTE TO CREATE IT

ONE HOUR OF EFFECT

PART FOUR — INSTANTANEOUS DURATION

INSTANTANEOUS

FOR A MOMENT

EXAMPLE — FIREBALL

DURATION: INSTANTANEOUS

THE FIREBALL SPELL ITSELF IS NO LONGER ONGOING

PART FIVE — INSTANTANEOUS DOES NOT MEAN "NO LASTING CONSEQUENCES"

MAGIC

AFTERWARD

FIREBALL EXAMPLE

INSTANTANEOUS

START BURNING

BURNING OBJECTS

PART SIX — FINGER OF DEATH: ANOTHER INSTANTANEOUS EXAMPLE

DURATION: INSTANTANEOUS

A ZOMBIE

INSTANTANEOUS DURATION

EVERYTHING CAUSED BY THE SPELL VANISHES IMMEDIATELY

PART SEVEN — HEROES' FEAST MAKES THIS EVEN CLEARER

DURATION: INSTANTANEOUS

24 HOURS

THE SAME NUMBER

PART EIGHT — DON'T TRY TO "BREAK CONCENTRATION" ON AN INSTANTANEOUS SPELL

NO CONCENTRATION

IT HAS ALREADY HAPPENED

UN-EXPLODE THE FIREBALL

THE EFFECT REQUIRES CONCENTRATION