I'm fairly sure WoTC would issue a similar official ruling for Unicorn Spirit + goodberry than it did for it with Discipline of Life.
A Sage Advice answer for this would go a long way to clear this up. If the intent was for there to be a "healing" class of spells and for Unicorn Spirit to trigger whenever one is cast I can't think of a way to rewrite the feature that doesn't introduce further ambiguity.
The way I see it there are three possible interpretations for how Unicorn Spirit triggers:
1) A spell is cast and it restores hit points simultaneously. Unicorn Spirits triggers immediately.
2) A spell is cast and it can restore hit points, either at the same time or in the future. Unicorn Spirits triggers when the spell is cast.
3) A spell was cast and it restores hit points. Unicorn Spirits triggers when the hit points are restored.
Interpretation 1 arises from reading "cast" and "restores" as being in the present tense.
Interpretation 3 arises from reading "cast" in the past tense and "restores" in the present tense. The conjugation of "cast" is the same in the second person present and second person past. Presumably the writers were using the same tense throughout the clause but not necessarily.
Interpretation 2 I personally don't see being supported by the text of the feature, but it is a popular interpretation. In order to support this interpretation there would need to be an auxiliary verb like "can" or "will" to transition into the future tense and then use the future tense conjugation "restore". However, rewriting the feature this way would introduce a lot of ambiguity about how to determine what spells qualify as others have previously mentioned.
Another solution would be to introduce a new school of magic. For example, if a school of magic called "Restoration" was added, then the feature could be rewritten to say: ". . . if you cast a restoration spell using a spell slot that can restore hit points to any creature inside or outside the aura, each creature of your choice in the aura also regains hit points equal to your druid level." This way any potential ambiguity about what spells count is resolved by the school of magic. Most direct healing spells are Evocation, but Goodberry is Transmutation, and spells like Revivify are Necromancy.
As for using the spells description to decide what counts I think that is a great approach for tables that like interpretation 2. This approach resolves a lot of the ambiguity and should avoid any surprise rulings. The comparison to summons though breaks down with more recently written spells as they include the creatures statistics in the spell description, like Summon Beast.
As for using the spells description to decide what counts I think that is a great approach for tables that like interpretation 2. This approach resolves a lot of the ambiguity and should avoid any surprise rulings. The comparison to summons though breaks down with more recently written spells as they include the creatures statistics in the spell description, like Summon Beast.
I think with the new self contained summon creatures its fine treating a creature designed to heal as part of a healing spell. I cant think of a specific example at the moment where any of the new self contained summons have the option of healing. (as a secondary point this also gives a way to solve other issues such as "can affect more than one creature" or "single target" or ending sanctuary.)
A Sage Advice answer for this would go a long way to clear this up. If the intent was for there to be a "healing" class of spells and for Unicorn Spirit to trigger whenever one is cast I can't think of a way to rewrite the feature that doesn't introduce further ambiguity.
The way I see it there are three possible interpretations for how Unicorn Spirit triggers:
1) A spell is cast and it restores hit points simultaneously. Unicorn Spirits triggers immediately.
2) A spell is cast and it can restore hit points, either at the same time or in the future. Unicorn Spirits triggers when the spell is cast.
3) A spell was cast and it restores hit points. Unicorn Spirits triggers when the hit points are restored.
Interpretation 1 arises from reading "cast" and "restores" as being in the present tense.
Interpretation 3 arises from reading "cast" in the past tense and "restores" in the present tense. The conjugation of "cast" is the same in the second person present and second person past. Presumably the writers were using the same tense throughout the clause but not necessarily.
Interpretation 2 I personally don't see being supported by the text of the feature, but it is a popular interpretation. In order to support this interpretation there would need to be an auxiliary verb like "can" or "will" to transition into the future tense and then use the future tense conjugation "restore". However, rewriting the feature this way would introduce a lot of ambiguity about how to determine what spells qualify as others have previously mentioned.
Another solution would be to introduce a new school of magic. For example, if a school of magic called "Restoration" was added, then the feature could be rewritten to say: ". . . if you cast a restoration spell using a spell slot that can restore hit points to any creature inside or outside the aura, each creature of your choice in the aura also regains hit points equal to your druid level." This way any potential ambiguity about what spells count is resolved by the school of magic. Most direct healing spells are Evocation, but Goodberry is Transmutation, and spells like Revivify are Necromancy.
As for using the spells description to decide what counts I think that is a great approach for tables that like interpretation 2. This approach resolves a lot of the ambiguity and should avoid any surprise rulings. The comparison to summons though breaks down with more recently written spells as they include the creatures statistics in the spell description, like Summon Beast.
I think with the new self contained summon creatures its fine treating a creature designed to heal as part of a healing spell. I cant think of a specific example at the moment where any of the new self contained summons have the option of healing. (as a secondary point this also gives a way to solve other issues such as "can affect more than one creature" or "single target" or ending sanctuary.)