Does the Sickening Radiance spell require the target to use their movement for the spell to deal damage?

Question

I just picked up the spell Sickening Radiance (XGtE, p. 164) and had a chance to try it out last session. The wording has caused some confusion and a disagreement between myself and my DM. The spell states:

When a creature moves into the spell's area for the first time on a turn or starts its turn there, that creature must succeed on a Constitution saving throw or take 4d10 radiant damage [...]

We were fighting multiple vampires. I cast Sickening Radiance on the enemy group. DM immediately rules that due to the language of the spell, they are not affected by it, since they "haven't started their turn in it" and they "didn't move into it". Okay, fair enough. They'll start their turn there, so I'm not concerned.

They start their turn within it and are dealt the damage. They then, logically, move out of the spell, but stand five feet out of it. Their turn ends, and my turn begins. I cast Eldritch Blast twice along with the Invocation Repelling Blast to push two of them 10 feet, which shoves them into the spell's effect area. The DM moves onto the next person; I gently remind him that they need to make Constitution saves for Sickening Radiance.

He refuses, stating that the language of Sickening Radiance uses "moves", not "pushed", and therefore is only triggered by the target using their movement, not just any movement into it. I obviously disagree, and argue that it just says "moves into", which they did, as a result of my Eldritch Blast.

Obviously DM fiat and all that, so if he says it doesn't work, it doesn't work. But I'm still curious about a rules based answer to this, as it seems like a very strict (and likely incorrect) reading.

Does Sickening Radiance require the target to use their movement (i.e. not be forcibly moved) for the spell to deal damage?

Answer 1

The "Opportunity Attacks" section of the PHB/basic rules states (emphasis mine):

You also don‘t provoke an opportunity attack when you teleport or when someone or something moves you without using your movement, action, or reaction.

There is linguistic precedent in the rule that the word "move" does not expressly refer to the voluntary use of one's own Speed.

In the absence of specific wording to make sickening radiance an exception to the general ruling of nearly identically worded spells, the overwhelming likelihood is that it behaves like all the other spells described in the April 2016 Sage Advice rules answers column:

Does moonbeam deal damage when you cast it? What about when its effect moves onto a creature?

The answer to both questions is no. Here’s some elaboration on that answer.

Some spells and other game features create an area of effect that does something when a creature enters that area for the first time on a turn or when a creature starts its turn in that area. The turn you cast such a spell, you’re primarily setting up hurt for your foes on later turns. Moonbeam, for example, creates a beam of light that can damage a creature who enters the beam or who starts its turn in the beam.

[...]

Reading the description of any of those spells, you might wonder whether a creature is considered to be entering the spell’s area of effect if the area is created on the creature’s space. And if the area of effect can be moved—as the beam of moonbeam can—does moving it into a creature’s space count as the creature entering the area? Our design intent for such spells is this: a creature enters the area of effect when the creature passes into it. Creating the area of effect on the creature or moving it onto the creature doesn’t count. If the creature is still in the area at the start of its turn, it is subjected to the area’s effect.

Entering such an area of effect needn’t be voluntary, unless a spell says otherwise. You can, therefore, hurl a creature into the area with a spell like thunderwave. We consider that clever play, not an imbalance, so hurl away! Keep in mind, however, that a creature is subjected to such an area of effect only the first time it enters the area on a turn. You can’t move a creature in and out of it to damage it over and over again on the same turn.

In summary, a spell like moonbeam affects a creature when the creature passes into the spell’s area of effect and when the creature starts its turn there. You’re essentially creating a hazard on the battlefield.

Answer 2

Thanks to @Szega for the link to the related question: Is the Moonbeam spell amazing, or are we doing it wrong?

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From the Sage Advice rules answers column from April 2016 (bold for emphasis added):

Reading the description of any of those spells, you might wonder whether a creature is considered to be entering the spell’s area of effect if the area is created on the creature’s space. And if the area of effect can be moved—as the beam of moonbeam can—does moving it into a creature’s space count as the creature entering the area? Our design intent for such spells is this: a creature enters the area of effect when the creature passes into it. Creating the area of effect on the creature or moving it onto the creature doesn’t count. If the creature is still in the area at the start of its turn, it is subjected to the area’s effect.

Entering such an area of effect needn’t be voluntary, unless a spell says otherwise. You can, therefore, hurl a creature into the area with a spell like thunderwave. We consider that clever play, not an imbalance, so hurl away! Keep in mind, however, that a creature is subjected to such an area of effect only the first time it enters the area on a turn. You can’t move a creature in and out of it to damage it over and over again on the same turn.

Most applicable to this question, and how it differs from moonbeam, is that the applicable answer is in the second paragraph quoted above: Yes, forcefully moving enemies into the area does cause them to be affected by the spell.

Answer 3

Spell functions like a gas, it doesn't care if you moved there voluntarily or not. That's common sense, nothing in the spell language asks whether you did it on purpose or not. And, nothing in the spell suggests you get to apply both effects twice, it states "Moves into OR starts the turn in" not AND. Big difference, meaning they made the save, failed, took damage, you pushed them back in, and tried a second save, DM ruled against it. Because it doesn't work that way.

Arguing whether or not movement has to be voluntary, with an effect that is clearly a magical AOE effect that is causing a SICKNESS is kind of crazy. Maybe if this was like, a Cursed wisdom save or something, but its constitution. So it doesnt care if you did it intentionally or not.

Answer 4

Jeremy Crawford tweeted recently, on the subject:

They have no special game meaning, other than that "moves" refers to movement. "Enter" is more open-ended.

https://twitter.com/JeremyECrawford/status/937859941892628481

This implies your DM, while personally disagree with him, is technically correct according to the Rules as the Written, or at least as the designers intended.

Answer 5

Yes, entering the spell's area only applies the effect "when a creature moves" there by itself

Your DM is right that "when a creature moves" exclusively refers to the creature moving itself using its "Movement, Action, or Reaction" which all rely on its Speed. That is, it doesn't include if a creature is hurled or pushed into the area (though it can be a nice setup for the spell effect to apply when the creature starts its turn there).

"When a creature moves" is what would also provoke Opportunity Attacks

The rules on Opportunity Attacks (PHB p. 195) defines what "when a creature moves" does and doesn't entail in D&D, emphasis mine:

You can make an opportunity attack when a hostile creature that you can see moves out of your reach. (...)

You can avoid provoking an opportunity attack by taking the Disengage action. You also don't provoke an opportunity attack when you teleport or when someone or something moves you without using your movement, action, or reaction. For example, you don't provoke an opportunity attack if an explosion hurls you out of a foe's reach or if gravity causes you to fall past an enemy.

That is, "when a creature moves" is defined such that:

1. It involves that the creature either uses its "Movement" (only on the creature's turn), "Action" (e.g. the Dash action), or "Reaction" (e.g. the Ready action, Dissonant Whispers, a Battle Master's Maneuvering Attack, a Scout's Skirmisher feature, or a Glamour Bard's Mantle of Inspiration). As a sidenote, the creature doesn't have to move willingly in the sense that the effect still applies if it uses its "Movement, Action, or Reaction" to move due to a Dominate spell, Confusion, or similar effects.
2. It doesn't include when "when someone or something moves you", such as "if an explosion hurls you".

Movement is a game term defined under Movement and Position (PHB p. 190):

On your turn, you can move a distance up to your speed. You can use as much or as little of your speed as you like on your turn, following the rules here.

Your movement can include jumping, climbing, and swimming. These different modes of movement can be combined with walking, or they can constitute your entire move. However you're moving, you deduct the distance of each part of your move from your speed until it is used up or until you are done moving.

Thus, Movement happens on your turn and uses your Speed in the form of walking, jumping, climbing, or swimming. Likewise, all of the examples I can find for using your Action or Reaction to move are also limited by your Speed (teleporting is explicitly excluded from the definition in the Opportunity Attacks section).

The section on Opportunity Attacks is the only relevant guidance from WoTC on what "when a creature moves" does and doesn't entail. Thus, the same guidelines should apply to Sickening Radiance and other instances of said wording. (Keep in mind that Disengage doesn't help you against Sickening Radiance but is specific to avoid provoking opportunity attacks.)

"Enters" is used instead if application "is more open-ended"

Are the terms "moves" and "enters" interchangeable or deliberate wording? Though only considered advice and no longer official rulings, in a tweet (thanks J. A. Streich), Jeremy Crawford clarifies that the distinction between "moves into" and "enters" is used deliberately as the two terms have different meanings, emphasis mine:

"Enters" and "moves into" mean enters and moves into, respectively, in D&D. They have no special game meaning, other than that "moves" refers to movement. "Enter" is more open-ended.

"Moves" refers to Movement which is a game term relying on a creature's speed as I account for above. On the contrary, a spell description will instead use the more general term "enters" if the spell effect is also supposed to take place when a creature is hurled or pushed into the spell's area as explained in Sage Advice 2016 regarding Moonbeam, emphasis mine:

Our design intent for such spells is this: a creature enters the area of effect when the creature passes into it. Creating the area of effect on the creature or moving it onto the creature doesn’t count. If the creature is still in the area at the start of its turn, it is subjected to the area’s effect.

Entering such an area of effect needn’t be voluntary, unless a spell says otherwise. You can, therefore, hurl a creature into the area with a spell like thunderwave. We consider that clever play, not an imbalance, so hurl away!

Sage Advice carefully outlines that this timing applies to spells such as "blade barrier, cloudkill, cloud of daggers, Evard’s black tentacles, forbiddance, moonbeam, sleet storm, and spirit guardians" - which is the complete list of spells in PHB for which the spell description uses the term "when a creature enters the area for the first time on a turn or starts its turn there". This consistency underlines that the wording is always used deliberately.

Furthermore, if the spell effects of Sickening Radiance and other spells that instead use the term "when a creature moves into the area for the first time on a turn or starts its turn there" where likewise supposed to apply when a creature is hurled into the area, they would have been included in said Sage Advice list of spells "with the same timing as moonbeam". Thus, by carefully omitting any spells that use the wording "moves into" rather than "enters", WoTC implicitly tell us that the two terms are not interchangeable but those spells should be handled differently. Apparently, WoTC thinks the section on Opportunity Attacks suffices as the only official guidelines on how to interpret the term "when a creature moves".

(The mechanic that "when a creature moves" triggers a spell effect is exclusively used for the following list of spells in PHB, XGE, and TCE: Booming Blade, Create Bonfire, Healing Spirit, Investiture of Flame, Sickening Radiance, Snare, Spike Growth, and Transmute Rock).