Does Cartomancer's Hidden Ace require you to expend a spell slot?

Question

The new Cartomancer feat from The Book of Many Things has a feature, Hidden Ace, that says "when you finish a long rest, you can choose one spell from your class's spell list and imbue that spell into a card." After this you can "you can use a bonus action to flourish the card and cast the spell within."

It could be compared to the magic items wand of magic missiles and rod of resurrection, in that it does not mention anything about spell slots:

While holding it, you can use an action to expend 1 or more of its charges to cast the magic missile spell from it.

While you hold it, you can use an action to cast one of the following spells from it: heal (expends 1 charge) or resurrection (expends 5 charges).

It could instead be compared to feats like Fey Touched which do mention "without using a spell slot":

You learn the Misty Step spell and one 1st-level spell of your choice. [...] You can cast each of these spells without expending a spell slot.

I thought the operative difference between the wand of magic missiles and the Hidden Ace feature might be the phrase "from it." In that case, Cartomancer would not allow you to cast the spell from the imbued card, it allows you to cast the spell (by expending a spell slot). However, the ring of spell storing does not use the phrase "from it" and implies you cast the spell, while not requiring the expenditure of a spell slot when casting.

While wearing this ring, you can cast any spell stored in it.

So, does the imbued card from Cartomancer's Hidden Ace feature allow you to cast the imbued spell without expending a spell slot (as wands, rods, and rigns do), or must you expend a spell slot because it doesn't say otherwise (as other feats do)?

Answer 1

No spell slot required.

The feat reads similarly to other spell storing effects and features, albeit much more poorly written in how vague it is.

The card is a consumable magic item

The description for what happens after it is used is "The card then immediately loses its magic." When it's imbued, it's a magic item. This is similar to the artificer class features and in line with the rule for consumable magic items:

Once used, a consumable item loses its magic.

Similar magic items

Casting a spell stored in a item such as hidden ace's "bonus action to flourish the card and cast the spell within" is a mechanic used by other magic items. E.g.:

• Ring of spell storing: "While wearing this ring, you can cast any spell stored in it."
• Spell gem from Out of the Abyss: "While holding the gem, you can cast the spell from it as an action..."
• Spell scroll: "A spell scroll bears the words of a single spell, written in a mystical cipher. ...you can read the scroll and cast its spell"

Casting from magic items doesn't use spell slots (unless stated)

Some magic items allow the user to cast a spell from the item. The spell is cast at the lowest possible spell and caster level, doesn't expend any of the user's spell slots, and requires no components, unless the item's description says otherwise.

Hidden ace doesn't describe that it requires components or spell slots.

Components Problem

The hidden ace ability is different from a ring of spell storing, spell gem, and scroll in that imbuing the spell into it does not require casting the spell. This gets around having to expend or have expensive components for some spells. A simple house rule would remedy this.

Answer 2

It doesn't matter whether or not the Ace is a magic item; it doesn't cost a slot.

Hidden Ace. When you finish a long rest, you can choose one spell from your class's spell list and imbue that spell into a card. The chosen spell must have a casting time of 1 action, and it must be a level for which you have spell slots. The card remains imbued with this spell for 8 hours. While the card is imbued with the spell, you can use a bonus action to flourish the card and cast the spell within. The card then immediately loses its magic.

Emphasis mine, the Ace is a self-contained (Feat)ure. The text tells you to pick a spell from your list and imbue it in the card (an unambiguous, discrete object within your inventory); the text is not instructing you to use your Spellcasting Feature to expend a slot and cast a spell here. The card is simply imbued with the spell.

The causal effect here is that you now have a card imbued with spell X. As a self-contained (Feat)ure, every cost associated with this card is printed in the text. Like any other text that tells you to cast a spell from an object, which the card most certainly is, regardless of whether or not it's magical, the only resource you use to cast that spell is what's printed with it; in this case, your bonus action.

One could lambaste WotC for being notorious for language inconsistencies, but that's only because there's so much printed material there's bound to be a few flubs. I think, however, that the easy tell for intentions behind the RAW lack of spell slots here, is that if you were meant to expend a spell slot they could have just recycled the language for Quicken Spell, and said when you cast the imbued spell you can expend the magic in the card to cast it as a bonus action.

Instead, they gave an object with a spell "imbued" in it, that you cast with a bonus action.

Answer 3

Yes, you must expend a spell slot.

Magic items specifically do not need to include any wording about expending a spell slot because there is a blanket rule that says magic items don't expend spell slots.

Some magic items allow the user to cast a spell from the item, often by expending charges from it. The spell is cast at the lowest possible spell and caster level, doesn’t expend any of the user’s spell slots, and requires no components unless the item’s description says otherwise

—Dungeon Master's Guide, Ch. 8

Hidden Ace does not say the card becomes a magic item, and in the absence of a similar general rule covering Hidden Ace (or any specific wording saying you don't have to expend a spell slot in the feature itself), you must expend spell slots to cast the spell as described in Ch. 10 of the Player's Handbook.

When a character casts a spell, he or she expends a slot of that spell’s level or higher

Answer 4

The card is not a magic item, so you need a spell slot

Not everthing that can hold magic is a magic item. There can be many items that hold magic, and still are no magic items:

• The identify spell can identify "a magic item or some other magic-imbued object", so there can be magic imbued objects that are no magic items, or there would be no need to mention them

• A coin enchanted with perpetual flame does not become a magic item, even though it is a magically, perpetually burning coin and will detect as magical

• The freezing sphere spell creates a bead that is not even an object

• illusionary script imbues a piece of paper with a potent illusion for the duration

To be a magic item, the an object needs to be either listed in a section in the rules that say the things in that section are magic items, or the rules need to tell you explicitly it is. The object itself must be magical, not just be a container or substrate for a magical effect.

Magic items are normally crafted, not created by an ability. If a feature can create one, the feature specifically tells you so. It is this specific statement that makes them a magic item. For example, look at the Artificer, which can also imbue magic into items with a feature. It explicitly states

Artificer infusions are extraordinary processes that rapidly turn a nonmagical object into a magic item.

The card does not state it is a magic item.

The rules for magic item in the DMG (p. 135) open with

Each magic item has a rarity: common, uncommon, rare, very rare, or legendary.

While this is true for items listed in the various magic item lists, items created by class features like the Artificer's infusions do not list a rarity. However, having a rarity would be a strong indication that a magical object is meant to be a magic item. The card also does not provide a rarity.

In summary, a magic items would need to either say it is one (explicitly or by being listed in a magic item section in the rules), or it would at least need to have a rarity to imply it is one. As the card does neither, it is not a magic item.

Because it is not a magic item (and with that, also not a consumable magic item), the rules for magic items that say no spell slots are expended when casting the spell do not apply here. You still have to expend the spell slot, as you are casting the spell.

The effect of Hidden Ace allows you to cast a one action spell as a bonus action, for one third of a feat pick, which is powerful enough in and of itself.