What is 'a fire elemental' for the purposes of a ring of fire elemental command?

Question

A similar potential ambiguity exists for the definitions of air, earth, and water elemental, but focusing on a ring of fire elemental command, how broad is the definition of 'a fire elemental'?

• Does the ring allow casting dominate monster on a CR11 efreeti?
• Does the ring allow casting dominate monster on a CR16 phoenix?
• Does the ring allow casting dominate monster on CR½ magma mephits, CR¼ steam mephits, and CR¼ smoke mephits?
• Does slaying one of the above grant the wearer the benefits of having helped 'slay a fire elemental'?
• Or is it exclusively referring to the CR5 monster with the name 'fire elemental'?

Unlike fiend (demon), fiend (devil), and fiend (yugoloth), there aren't any explicit tags that further classify the creature type Elemental, and the 4 magic rings of elemental command seem to be the only part of the game that might even care about the distinction (and mephits complicate any potential distinction).

Answer 1

The Monster Manual defines elementals

Elemental is a Monster Type (MM 6). It is defined as:

Elementals are creatures native to the elemental planes. Some creatures of this type are little more than animate masses of their respective elements, including the creatures simply called elementals. Others have biological forms infused with elemental energy. The races of genies, including djinn and efreet, form the most important civilizations on the elemental planes. Other elemental creatures include azers, invisible stalkers, and water weirds.

From this description, it is clear that the fire elemental is just one example of what a fire elemental can be. Any creature native to the Plane of Fire is a fire elemental, and would be treated as such for the purposes of the ring.

This understanding is further confirmed by two spells found in the PHB. In conjure minor elementals, we read:

You summon elementals that appear in unoccupied spaces that you can see within range. You choose one the following options for what appears:
One elemental of challenge rating 2 or lower
Two elementals of challenge rating 1 or lower
Four elementals of challenge rating 1/2 or lower
Eight elementals of challenge rating 1/4 or lower.

Note that these creatures are simply called "elementals", and that none of them can be CR5, that of the elementals. Upcasting the spell conjures more of them, but does not increase their power. The spell says that "The DM has the creatures' statistics", so it is the DM who chooses whether they are fire elementals or some other element.

Then we have the conjure elemental spell, which says (emphasis mine):

You call forth an elemental servant. Choose an area of air, earth, fire, or water that fills a 10-foot cube within range. An elemental of challenge rating 5 or lower appropriate to the area you chose appears in an unoccupied space within 10 feet of it. For example, a fire elemental emerges from a bonfire...

Here, you can specifically conjure "a fire elemental" by targeting an area of fire, but note that the elemental conjured is CR5 or lower, meaning it is possible to get the fire elemental, but also explicitly possible to get a fire elemental should the DM decide.

Further, as Nobody the Hobgoblin points out in a comment, the conjure elemental spell can be upcast, and when you do so, "the challenge rating increases by 1 for each slot level above 5th."¹. If the fire elemental was the only or the primary creature conjured by this spell, there would be no reason for this ability, whereas, for example, upcasting an air elemental to CR6 might bring you an invisible stalker, as suggested by the additional text on the DDB description of the spell.

As just mentioned, on D&D Beyond², the spell description goes, well, beyond what is written in the PHB and lists magma mephits, magmin, azer, and salamanders as examples of what you might conjure with this spell in addition to the eponymous fire elemental, further supporting that "a fire elemental" does not mean only the fire elemental.

The Moon Druid's elemental wild shape is an exception

As pointed out by @PeterCordes in a comment, Moon Druids can gain the elemental wild shape ability, which says:

At 10th level, you can expend two uses of Wild Shape at the same time to transform into an air elemental, an earth elemental, a fire elemental, or a water elemental.

Here, we uncharacteristically take "a fire elemental" to mean only the fire elemental. This is clarified by a Sage Advice Compendium ruling which says:

Does the druid’s Elemental Wild Shape limit you to the four creatures listed, or can you turn into any creature with the elemental type? The creatures listed in Elemental Wild Shape—air, earth, fire, and water elementals—are specific creatures in the Monster Manual, not creature types or subtypes. Elemental Wild Shape allows you to transform into one of those creatures.

It should be noted that Sage Advice is saying "this is how elemental wild shape works", and is not saying "this is what 'an elemental' means in rules text". The ruling here is a specific exception to the general rule established the Monster Manual.

There is no explanation given for why this particular ability is more restrictive than, say, the spells to which a Moon Druid already has access (conjure elemental, conjure minor elemental), but it may have to do with scaling the CR of the elemental form. In their wild shape, Moon Druids are permitted to assume forms "with a challenge rating as high as [their] druid level divided by 3, rounded down", and at 10th level this would be CR3 (the fire elemental is CR5). The elemental wild shape ability is separate and distinct from the wild shape ability, though, and has no CR limitation any more than it requires the druid to have previously seen the form in question. However, if elemental wild shape both permitted any elemental form and were untethered from CR, then a 10th level druid could take the shape of, for example, a legendary CR16 phoenix. Thus using the same CR scaling as for wild shape would not permit a druid to have access to the fire elemental at the level they received elemental wild shape, but having no scaling would permit them forms that are clearly over-powered for their level. I think it is likely that designers had to choose between creating a new CR scaling for just this ability, or simply restricting elemental wild shape to the eponymous elementals (which also may have aligned better with previous editions), and they chose the latter.

---

¹ It is not obvious what increasing the challenge rating of a creature of "5 or lower" does. Does it increase the maximum, the minimum, or both? That is, if I cast conjure elementals at 6th level, would I get an elemental with a CR range of 0 to 6, 1 to 5, or 1 to 6 (all inclusive)?

² Whether this table (or that included with conjure minor elemental) is "official" content is debatable, and see this comment by user10063. What is not debatable is that the PHB in both spells calls creatures of less than CR5 elementals, and in the second spell explicitly says that conjuring fire elementals of less than CR5, and probably more than CR5, is possible.

Answer 2

They're all fire elementals

The magic item description, describing all four rings, uses the term 'elementals from the linked plane':

This ring is linked to one of the four Elemental Planes. The DM chooses or randomly determines the linked plane.

While wearing this ring, you have advantage on attack rolls against elementals from the linked plane, and they have disadvantage on attack rolls against you. In addition, you have access to properties based on the linked plane.

Only afterwards, when describing the properties of a specific ring, does it use the term 'fire elemental' instead. These are completely separate properties from this first property about advantage and disadvantage on attack rolls, so technically they have completely independent semantics. But this all ultimately hinges on a sub-question:

Is 'a fire elemental' just a shorter synonym for 'elementals from the linked plane'?

The answer to this seems emphatically yes, so everything from the destructive phoenix down to the mischievous half-fire mephits would qualify as 'a fire elemental.' Because a further sub-question raised is...

How useful would the ring be if the definition were so extremely narrow?

The ring of fire elemental command is a magic ring of legendary rarity that requires attunement. If you go with the default guidelines in the DMG, legendary items appear only at the very highest tier of play, 17th level or later. It has only a 1% chance of being found when rolling on the most powerful random magic items table, Magic Item Table I, putting it among the top 25 items alongside the deck of many things and talisman of pure good.

Rarity provides a rough measure of an item's power relative to other magic items. Each rarity corresponds to character level, as shown in the Magic Item Rarity table. A character doesn't typically find a rare magic item, for example, until around 5th level.

The ring is supposed to be extremely powerful and versatile. And by the time a character reaches 17th level, slaying any fire elemental weaker than a phoenix isn't even a challenge. A ring of water elemental command should work on a water weird, a ring of earth elemental command should work on a xorn, a ring of air elemental command should be able to send an invisible stalker right back at its master.

But the D&D Beyond website disagrees?

The page for the ring of fire elemental command on dndbeyond.com turns both mentions of the term 'fire elemental' into a hyperlink to the monster page for the one and only fire elemental. That seems to debunk the whole argument, right?

But D&D Beyond has in the past also given the gelatinous cube the ability to see, before correcting their error, so they're not infallible and capable of accidentally contradicting both the letter and the spirit of the sourcebooks. The un-paywalled, individual pages for spells, monsters, and magic items are ultimately crudely derived from their original, unadulterated format in the 'Spell Descriptions,' 'Monster Stat Blocks,' and 'Magic Item Descriptions' sections of the Basic Rules. (Notably, the term 'fire elemental' is not a hyperlink to any specific monster's page in the original magic item description, but the term 'djinni' is a hyperlink in the original magic item description for the ring of djinni summoning, as are the individually identifiable monsters in an iron flask.)

Answer 3

The advantage is granted against any elemental from the Fire Plane, the spell and the slaying refer to the Fire Elemental monster.

The answer comes from the item description on DnDBeyond, which is an official source since its acquisition from Wizards of the Coast.

The description of the magic item says (emphases mine, links as in the original page):

While wearing this ring, you have advantage on attack rolls against fire elementals, and they have disadvantage on attack rolls against you. [...]

You can expend 2 of the ring's charges to cast dominate monster on a fire elemental. [...]

If you help slay a fire elemental while attuned to the ring, you gain access to the following additional properties

In the first sentence, the advantage on attack rolls is granted against fire elementals (plural) and it does not link to the Fire Elemental monster page. This means that such advantage is granted for any monster with the type Elemental and which are linked to the fire element. In particular, Magma mephits are eligible, since they are composed by earth and fire, per description.

The other sentences, regarding the spell Dominate Monster and the benefits from slaying a fire elemental, refer to the Fire Elemental monster: the item description links to the stat page of this particular monster.

This is supported by the fact that the plural of the first sentence does not link to the stat page of the Fire Elemental, as it happens for the Pipes of the Sewers when it refers to rats and giant rats.

A DM could rule otherwise

Without the web version of this item and referring only on the physical manuals, a DM had to make a call and decide how to interpret the fire elemental entries in the item's description.

Even with the confirmation via the DnDBeyond page, a DM could overrule it and decide how the item works when interacting with elementals from the Fire Plane.