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From RAW, it's clear that a character can ready a spell that has a casting time of 1 action and release the spell when the trigger occurs or directly after the trigger finishes1: Provided, that the character's concentration is not broken.2

Is there any time limit (rounds, turns, etc.) on how long a character can hold a readied spell, as long as concentration is maintained?

Example 1: How long can I wait just around the corner with a readied lightning bolt having a trigger of "I release the spell when a creature (or anything) comes around the corner"?

Example 2: How long can a back row spellcaster hold a readied dimension door with a trigger of "If an enemy breaks through the front line, then I release the spell"? Which would allow the spellcaster to move and attack with a ranged weapon each turn with an escape plan. ("Normal activity, such as moving and attacking, doesn't interfere with concentration." PBR, p. 80; PHB, p. 203)

  1. Under "Adjudicating Reaction Time" in the Dungeon Master's Guide:

    Use this rule of thumb: follow whatever timing is specified in the reaction's description. For example, the opportunity attack and the shield spell are clear about the fact that they can interrupt their triggers. If a reaction has no timing specified, or the timing is unclear, the reaction occurs after its trigger finishes, as in the Ready action. [Emphasis added] (DMG, p. 252)

  2. According to the Player's Basic Rules and Player's Handbook:

    When you ready a spell, you cast it as normal but hold its energy, which you release with your reaction when the trigger occurs. To be readied, a spell must have a casting time of 1 action, and holding onto the spell's magic requires concentration. If your concentration is broken, the spell dissipates without taking effect. For example, if you are concentrating on the web spell and ready magic missile, your web spell ends, and if you take damage before you release magic missile with your reaction, your concentration might be broken. [Emphasis added] (PBR, p. 72; PHB, p. 193)

Nobody the Hobgoblin
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sadaqah
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6 Answers6

46

The recently released Player's Handbook Errata clarifies this:

Ready (p. 193). You have until the start of your next turn to use a readied action.

Mars Plastic
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Dyndrilliac
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    Is there not an argument to be made that this doesn't actually say the spell is lost? Just the action? I don't see why you wouldn't be able to "ready" the release of the spell repeatedly, so long as you continue to maintain concentration. The rule prevents you from storing up actions round after round and releasing them all at once, but as long as you spend your action each round for a new "ready" I don't see why it would waste your spell too. – zeel Apr 22 '20 at 16:42
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Before the start of your next turn.

The Ready action specifies in its description that you can only hold your action until the start of your next turn. (PHB, p. 193)

The notes about concentration and the breaking thereof are additional to this limit, not a replacement thereof — it specifies that the normal Ready-Reaction timing stays the same when it says

you cast [the spell] as normal but hold its energy, which you release with your reaction when the trigger occurs.

There are no other notes about Readying spells being different than Readying any other action, so they get no special treatment and expire like any other Readied action.

This is ripe for house ruling though. I imagine it will be a relatively common house rule, either on purpose or by accident of not noticing the limit in the first place.

It would have a significant impact on party tactics though (as your dimension door example demonstrates), and will likely be polarising between different groups or between players used to one way joining groups with DMs used to running it the other way.

Nanashi No Gombe
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SevenSidedDie
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    The sentence of the Ready action description quoted above by @sadaqah was revised in the very first errata in 2015. It now reads: "To do so, you can take the Ready action on your turn, which lets you act using your reaction before the start of your next turn." It no longer references "later in the round". You may want to update your answer accordingly. – V2Blast Aug 29 '19 at 02:41
  • @V2Blast the errata you have linked to in your comment is the version 2, 2018 errata (as evidenced by the footer of the document you linked). The 2015 Errata, linked correctly in the comment under my answer, has the text quoted in the currently accepted answer, but does not change the wording to what you have quoted. – illustro Aug 29 '19 at 13:41
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    I think that just makes a cosmetic change, but I haven’t had the time/chance to re-immerse myself in the Q, what I wrote, and the sources to make sure. I’ll try to remember to revise when I can, but if someone takes a stab at it before then I will not object! – SevenSidedDie Aug 29 '19 at 17:53
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    @SevenSidedDie: You are correct. All that changed was that the 2018 errata no longer paraphrases changes, and instead accurately quotes the revised text. (I've fixed the link in my previous comment to point to the right URL using my magic mod powers.) – V2Blast Aug 29 '19 at 18:18
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p 192 of the PH say

When you take your action on your turn, you can take one of the actions presented here ...

p 193 says

When you ready a spell, you cast it as normal but hold its energy, which you release with your reaction when the trigger occurs. To be readied, a spell must have a casting time of 1 action, and holding onto the spell’s magic requires concentration (explained in chapter 10).

So, you take ready (a spell), the trigger does not occur and your turn rolls around again. So, what can you do?

As written, the "energy" is not released so to my mind I can see several options:

  1. Its gone - too bad
  2. You could take Ready again with the same trigger
  3. ... or a different trigger; possibly including the trigger "Now!" (equivalent to 4.)
  4. You could take the "Cast a Spell" action to release the energy
  5. You could take any other action and so long as you maintain concentration the spell is sitting like a malignant toad in your brain ready to be used on some future action ("Cast a Spell" or "Ready").

Personally, I would rule any or all of 2-5 as No 1 would pretty seriously discourage the use of Ready to cast a spell and none of the others seem overpowered - essentially you have given up an action and a spell slot and concentration for some nebulous future benefit. Contrast this with Ready vis a vis any other action which only makes you give up your action.

The advantage of this is it is readily applicable in a non-combat situation, the same mechanics are in play, just implicitly rather than explicitly, so you can hold the spell until you use it or your concentration breaks (voluntarily or involuntarily); effectively taking Ready round after (implicit) round.

Dale M
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  • For non-cantrips, would you say that the spell slot is used when the spell is readied or when it's released? – SevenSidedDie Jan 18 '15 at 02:10
  • NRBH but I would say it is when the spell is cast, "readying" means pre-planning the (re)action you will take in response to the trigger - it is not the action itself. – Dale M Jan 19 '15 at 00:31
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    @SevenSidedDie I interpreted it the opposite way: "you cast it as normal but hold its energy." Casting as normal involves expending a spell slot. – detly Jul 08 '15 at 06:39
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    @detly I have reviewed the PHB and I agree with your interpretation. – Dale M Jul 08 '15 at 06:58
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Sage Advice Compendium: only until the start of your next turn

How to rule this has been clarified in the Sage Advice Compendium. Here is the entry (Version 2.7):

How does readying a spell work? Do you lose your spell slot if the trigger never occurs? A readied spell’s slot is lost if you don’t release the spell with your reaction before the start of your next turn.

This ruling confirms the conclusion given in Dyndrilliac's answer.

Thomas Markov
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Nobody the Hobgoblin
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  • Presumably 'lost' here contrasts with 'is used' rather than 'is not lost'. Otherwise, if I cast my readied spell before my next turn, I would not lose the slot! – Kirt Dec 27 '22 at 17:47
  • @Kirt Yes, the answer is in the context of the question, i.e. what happens if you readied the spell and the trigger never occurs. If the trigger occurs and you release the spell, you of course also will lose the spell slot. – Nobody the Hobgoblin Dec 27 '22 at 17:51
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The Errata on this section has changed (as of the 2018 errata) and as a result readied spells can be held for as long as desired.

The errata now reads:

Ready (p. 193). The second sentence now reads, “To do so, you can take the Ready action on your turn, which lets you act using your reaction before the start of your next turn.”

This wording no longer precludes holding a readied spell for as long as you like, as the Ready action no longer mandates that it must be used by the start of your next turn. Instead the Ready action now enables you to act using your reaction before the start of your next turn.

The specific rule for holding spells is detailed later in the Ready section:

When you ready a spell, you cast it as normal but hold its energy, which you release with your reaction when the trigger occurs. To be readied, a spell must have a casting time of 1 action, and holding onto the spell's magic requires concentration (explained in chapter 10).

So holding onto the spell now only requires concentration. Actually releasing the readied spell, requires a reaction. This reaction can be re-enabled by future use of the Ready action.

illustro
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    Readied actions only last until the "start of your next turn" so you cannot hold them indefinitely – Exempt-Medic Aug 28 '19 at 22:53
  • @Medix2 read the updated errata quote in my answer. It replaces the one in the accepted answer on this question. Thus the accepted answer on this question no longer applies. – illustro Aug 28 '19 at 22:57
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    The 2018 errata doesn't change the Ready action at all. That change was made in the very first errata in 2015. The only thing it changed was that the second sentence of the description of the Ready action originally read: "[...] take the Ready action on your turn so that you can act later in the round using your reaction." It now reads as quoted: "take the Ready action on your turn, which lets you act using your reaction before the start of your next turn." – V2Blast Aug 29 '19 at 02:37
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    In short, nothing has changed about how readied spells work as of the 2018 PHB errata. The revised wording as of the first errata is exactly what prevents any readied action from being held past the start of your next turn. – V2Blast Aug 29 '19 at 02:39
  • @V2Blast the 2015 errata specified "You have until the start of your next turn to use a readied action" as quoted in the accepted answer to this question. The 2018 Errata reverses this 2015 errata addition, it also reorders the wording of that Errata. So yes, the 2018 errata *does* change the Ready action compared to the 2015 Errata. – illustro Aug 29 '19 at 13:34
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    All that changed was that the 2018 errata no longer paraphrases changes, and instead accurately quotes the revised text. The 2018 errata doesn't change the rule at all. In fact, it quotes the exact sentence that was changed in the 2015 errata - the one I mentioned in my previous comment. The fact that there was no change here in the 2018 errata can be seen by the fact that it's not marked as "[New]", and by actually comparing newer PHBs to any PHB printed after the 2015 errata. Whether or not you think the current wording allows infinite readying (it doesn't), it wasn't changed in 2018. – V2Blast Aug 29 '19 at 18:21
  • @V2Blast the function of the 2015 errata is different to the 2018 errata. The 2015 errata's function was to provide rules clarifications (or RAI), as a result of changed text, a function now fulfilled by the Sage Advice Compendium. The 2018 errata no longer provides this rule clarification, instead it provides changes to the text of the rules as a stand-alone. The fact that the rule clarification is no longer provided is significant. – illustro Aug 30 '19 at 07:17
  • I'm also not saying it allows infinite readying. I'm saying that specifically for spells you can maintain the spells energy indefinitely (at the expense of your concentration). Actually maintaining the ability to release that held energy using your reaction requires subsequent reuse of the Ready action. – illustro Aug 30 '19 at 08:09
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The spell slot is consumed as you ready the spell. According to the official rules, you can only maintain concentration until the start of your next turn (see Sage Advice).

That said, it's probably a common house rule (which probably includes Jeremy Crawford's table) that you can maintain concentration for more than six seconds.

Personally, I'd allow it to be held indefinitely. After a considerable amount of time (e.g. during a short rest), I'd call for one or two constitution saving throws with DC 10, depending on the environment. Of course, if the character were to sleep (as in during a long rest), the character would become unconscious, and thus incapacitated, which would break concentration. If that character didn't need to sleep (i.e. the Elf's trance trait), then I'd also say that the concentration was broken during the trance.

I would allow characters to change the trigger as an action on their turn (effectively, taking the ready action again). The characters could also release the energy as an action on their subsequent turns.

Thomas Markov
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GregNash
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