D&D 5E Please help me with the “one spell cast per round” rule

krunchyfrogg · Jan 10, 2018

Please help me with the “one spell cast per round” rule

Where is this rule written?

Does it apply to all spells? Are cantrips an exception? Are bonus action spells an exception?

I’ve just had trouble with this rule and thought you guys could explain it to me.

TallIan · Jan 10, 2018

P 202 of the PHB under the bonus action heading of the casting time section.

"You can't cast another spell during the same turn, except for a cantrip with a casting time of I action."

Note that its TURN and not round so you can still cast a reaction spell, like shield, for three spells - a cantrip for your action, a levelled spell with a casting time of bonus action as a bonus action and another spell with a casting time of reaction as your reaction.

mellored · Jan 10, 2018

There is no "one spell per round" rule. You can cast greater invisibility, action surge to cast fireball, and jump off a cliff and cast feather fall all on the same turn, no problem.

There is a "bonus action spell" rule. If you cast a bonus action spell, you can only cast cantrips for your turn.

So a quicken fireball and a fire bolt, but not feather fall, no action surge greater invisibility. You can cast multiple cantrips spells though. So quicken fireball, + mage hand + action surge minor illusion.

Spells that take multiple turns are not "casting". For instance, if you cast spiritual weapon, you could only cast sacred flame as your action.
But on later turns, you could bonus-action-repeat-attack-with-spiritual-weapon, and still cast any other spell you want.
Or call lighting on turn 1, and later turns do bonus casting healing word, with not-casting-repeat-attack with call lighting on later turns.

ClaytonCross · Jan 10, 2018

mellored said:
There is no "one spell per round" rule. You can cast greater invisibility, action surge to cast fireball, and jump off a cliff and cast feather fall all on the same turn, no problem.

There is a "bonus action spell" rule. If you cast a bonus action spell, you can only cast cantrips for your turn.

So a quicken fireball and a fire bolt, but not feather fall, no action surge greater invisibility. You can cast multiple cantrips spells though. So quicken fireball, + mage hand + action surge minor illusion.

Spells that take multiple turns are not "casting". For instance, if you cast spiritual weapon, you could only cast sacred flame as your action.
But on later turns, you could bonus-action-repeat-attack-with-spiritual-weapon, and still cast any other spell you want.
Or call lighting on turn 1, and later turns do bonus casting healing word, with not-casting-repeat-attack with call lighting on later turns.

Technically You can Action: cast greater invisibility, Bonus action quicken meta magic: fire bolt, jump off a cliff and reaction cast:feather fall, then action surge cast action: fireball all on the same turn to make it look like multiple people attacking from different locations for an example of showing maximum potential of casting 4 spells on a single turn.

So Action, Action Surge Action, Reaction, Bonus action all cast spells but your bonus action can't be an a full spell unless your bonus is a cantrip.

Not much of an add, just figured it was worth a minor note. I think most of the time Warcaster/counter spell/shield/absorb elements are your normal uses of reaction to cast a spell.

So unless your a Sorcerer/Fighter multiclass you might see 3 but 2 is pretty common.

Volund · Jan 10, 2018

ClaytonCross said:
So Action, Action Surge Action, Reaction, Bonus action all cast spells but your bonus action can't be an a full spell unless your bonus is a cantrip.

Cantrips are spells. If you cast anything, including a cantrip, with your bonus action, you can't cast anything but cantrips during your turn.

For the OP, there is Sage Advice guidance on your question: http://media.wizards.com/2017/dnd/downloads/SA-Compendium.pdf

Greenstone.Walker · Jan 10, 2018

ClaytonCross said:
You can Action: cast greater invisibility, Bonus action quicken meta magic: fire bolt

If you cast a spell with a casting time of bonus action (which quickened spells are) then, "You can't cast another spell during the same turn, except for a cantrip with a casting time of 1 action." [PHB, chapter 10].

Since you have already cast a spell on this turn that isn't a cantrip (greater invisibility) then you cannot meet this requirement, so you cannot cast the quickened fire bolt.

You could use an action to cast fire bolt and a bonus action to cast a quickened greater invisibility. You still wouldn't be able to follow it up with using a second action to cast fireball.

You could cast a quickened greater invisibility (bonus action) with two castings of fire bolt (one action plus a second action from action surge).

ClaytonCross said:
reaction cast:feather fall,

Feather fall is not a cantrip with a casting time of 1 action so you can't cast it on the same turn as a quickened spell.

Note that you can cast more than one non-cantrip spell in a round. For example, you can cast two fireballs, one with an action and one with the second action provided by action surge. The cantrip limitation only applies when you have cast a spell with a casting time of 1 bonus action.

cbwjm · Jan 10, 2018

According to that sage advice compendium. A caster with action surge is able to cast a bonus action spell, a cantrip with their action then use action surge and then cast a spell that uses an action.

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UberZS · Jan 10, 2018

I also always wandered this. This helps clarify a lot of it.

ClaytonCross · Jan 10, 2018

Greenstone.Walker said:
If you cast a spell with a casting time of bonus action (which quickened spells are) then, "You can't cast another spell during the same turn, except for a cantrip with a casting time of 1 action." [PHB, chapter 10].

Since you have already cast a spell on this turn that isn't a cantrip (greater invisibility) then you cannot meet this requirement, so you cannot cast the quickened fire bolt.

You could use an action to cast fire bolt and a bonus action to cast a quickened greater invisibility. You still wouldn't be able to follow it up with using a second action to cast fireball.

You could cast a quickened greater invisibility (bonus action) with two castings of fire bolt (one action plus a second action from action surge).

Feather fall is not a cantrip with a casting time of 1 action so you can't cast it on the same turn as a quickened spell.

Note that you can cast more than one non-cantrip spell in a round. For example, you can cast two fireballs, one with an action and one with the second action provided by action surge. The cantrip limitation only applies when you have cast a spell with a casting time of 1 bonus action.

I don't think this limitation applies to reaction spells like shield for example. That said the bonus limitation is to your turn, so casting shield as a reaction on the same round during an enemies turn is not denied at all, nor would cast Feather Fall for being knocked off a ledge by a warlocks repelling blast for example. It seems to me that the reaction effect on your turn or on another s turn would supper seceded the action economy of bonus action / action the same way action surge does.

If I use Action: cast greater invisibility, Bonus action quicken meta magic: fire bolt, action surge cast action: fire bolt, and reaction cast: shield/counter spell on my enemies turn for example there is not issue. So the semantic hate is basically only against slow-fall? I tried to find a sage advice clarification but could not. I would just rule it a cleaver use of under used spell since its not the limit of casting the spell in the round that holds it back.

"B o n u s A c t io n
A spell cast with a bonus action is especially swift. You must use a bonus action on your turn to cast the spell, provided that you haven’t already taken a bonus action this turn. You can’t cast another spell during the same turn, except for a cantrip with a casting time of 1 action."

"R e a c t io n s
Some spells can be cast as reactions. These spells take a fraction of a second to bring about and are cast in response to some event. If a spell can be cast as a reaction, the spell description tells you exactly when
you can do so."

5ekyu · Jan 10, 2018

ClaytonCross said:
I don't think this limitation applies to reaction spells like shield for example. That said the bonus limitation is to your turn, so casting shield as a reaction on the same round during an enemies turn is not denied at all, nor would cast Feather Fall for being knocked off a ledge by a warlocks repelling blast for example. It seems to me that the reaction effect on your turn or on another s turn would supper seceded the action economy of bonus action / action the same way action surge does.

If I use Action: cast greater invisibility, Bonus action quicken meta magic: fire bolt, action surge cast action: fire bolt, and reaction cast: shield/counter spell on my enemies turn for example there is not issue. So the semantic hate is basically only against slow-fall? I tried to find a sage advice clarification but could not. I would just rule it a cleaver use of under used spell since its not the limit of casting the spell in the round that holds it back.

"B o n u s A c t io n
A spell cast with a bonus action is especially swift. You must use a bonus action on your turn to cast the spell, provided that you haven’t already taken a bonus action this turn. You can’t cast another spell during the same turn, except for a cantrip with a casting time of 1 action."

"R e a c t io n s
Some spells can be cast as reactions. These spells take a fraction of a second to bring about and are cast in response to some event. If a spell can be cast as a reaction, the spell description tells you exactly when
you can do so."

unless i am mistaken you can do the bonus action spell and a cantrip 1 action spell ON YOUR TURN and then could AFTER YOUR TURN cast a reaction because that is a new turn.

but you could *not* cast a bonus action spell, cast an action cantrip and then still in your turn step off a ledge and reaction cast FF because that is still on your turn. I think someone suggested this earlier.

This is similar to how you can get sneak attack for one attack on your turn and them possibly again as a reaction AFTER your turn.

The only thing special for reactions to various "once per turn" I know of comes when they occur on other folks turns and as such get around your own per turn limitations.