Can a sorcerer cast two leveled spells per turn if one of them is from activating a magic item?

Question

I'm running the Out of the Abyss campaign for my players, and I've hit an edge case for the Sorcerer with Quickened Spell metamagic. The character has a Spell Gem (from Out of the Abyss: you stuff a spell into it, and then spend an action later to have the Gem cast the spell at the Gem's level and save DC).

Can a sorcerer cast two leveled spells in a turn, if they use both Quickened Spell and a Spell Gem? Does this generalize to a sorcerer casting two spells in a turn as long as one of them is from activating an item?

Quickened Spell: When you cast a spell that has a casting time of 1 action, you can spend 2 sorcery points to change the casting time to 1 bonus action for this casting.

Spell Gem: While holding the gem, you can cast the spell from it as an action if you know the spell or if the spell is on your class’s spell list. Doing so doesn’t require any components and doesn’t require attunement.

(I GM by having a small number of hard/deadly encounters rather than a larger number of smaller encounters – because it makes each encounter have significant stakes, and because Out of the Abyss doesn't restrict resting terribly much in the first half of the campaign. So if the sorcerer can go nova with two leveled spells per round for 2-3 rounds, that does a lot of damage without really restricting his ability to cast spells at the next encounter.)

Answer 1

You can't cast a levelled spell from it if you already cast a bonus action spell

Spell Gem:

While holding the gem, you can cast the spell from it as an action if you know the spell or if the spell is on your class's spell list.

It does not use your spell DC, but you are still the caster.

Generally

It would depend on the wording, but all items I have seen so far makes you clearly the caster.

Answer 2

If you cast a spell with a casting time of 1 bonus action then:

You can’t cast another spell during the same turn, except for a cantrip with a casting time of 1 action.

Note the prohibition only applies if you use your bonus action to cast a spell. If you only use actions (noting there are ways to get more than one e.g. The Fighter's Action Surge) or reactions (unlikely but you could dive off a cliff to use Feather Fall or provoke an Opportunity Attack and use Shield) then as many of those as you can cast can be of any level.

However, if you use a spell with a casting time of 1 bonus action you can only cast 1 cantrip (even if the bonus action spell is itself a cantrip or not) no matter how many actions/reactions you have.

The Sorcerer's Quickened Spell metamagic changes the casting time of a 1 action spell to 1 bonus action, triggering the limitation.

The gem requires that "you cast the spell" - a lot of magic items are explicit that it is you who are casting - and so the limitation applies even if this is the source.

Answer 3

I'm very glad I found this question, as I have the same question, but with a different context. I am also running Out of the Abyss, and have a Sorcerer with a Spell Gem. My Sorcerer, on the other hand, did not take Quickened Spell, but does now have Haste:

Haste: Choose a willing creature that you can see within range. Until the spell ends, the target’s speed is doubled, it gains a +2 bonus to AC, it has advantage on Dexterity saving throws, and it gains an additional action on each of its turns. That action can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action.

I believe that using a Spell Gem is exactly that: Us[ing] an Object, not Cast[ing] a Spell (action type). As this is an action, not a bonus action, I believe that her non-Haste action is free to be Cast a Spell, thus achieving two leveled spell castings in one turn, for as many turns as she is Hasted and has loaded Spell Gems (which is one, in this case).

This answer is effectively a concurrence with all of the existing answers, and extends them by adding in another special case.

Answer 4

They shouldn't be able to. If the Sorcerer is using the gem, and it counts as an action, then they would only have a bonus action left on their turn. Vice versa should apply to all of their known spells. The only case in which they could use both, if the gem use counted as a bonus or free action.