Is the additional damage dealt by Elemental Bane dealt by Elemental Bane?

Question

The first time each turn the affected target takes damage of the chosen type, the target takes an extra 2d6 damage of that type.

Would this damage be considered to by made by the Elemental Bane spell and its caster?

For a scenario where this might matter, consider the Awakened Spellbook ability from the Order of Scribe:

you can temporarily replace its damage type with a type that appears in another spell in your spellbook

So if the additional damage is considered to be damage dealt from Elemental Bane, you could change its type. As a result, Elemental Bane could trigger from a fire hit but deal piercing damage (inspired by this question).

This is just an example of why this would matter and there might be other features interacting with the source of damage eg the Pyromancer Sorcerer's Fiery Soul that ignores resistance for fire damage.

Answer 1

Yes, it is

The extra damage is part of the spell's effect, as given in the spell description. P. 202 PHB:

Each spell description in chapter 11 begins with a block of information, including the spell’s name, level, school of magic, casting time, range, components, and duration. The rest of a spell entry describes the spell’s effect.

By default, damage a spell deals is from the spell. The spell effect would need to say that the attack or the source deals the extra damage, for the damage to count as part of the attack or source instead. For example, compare this to the text of Searing Smite which says:

The next time you hit a creature with a melee weapon attack during the spell’s duration, your weapon flares with white-hot intensity, and the attack deals an extra 1d6 fire damage to the target and causes the target to ignite in flames.

In the case of Searing Smite, the effect tells you the attack deals the extra damage. For Elemental Bane, there is no such language, and thus the damage is dealt by the spell itself, not the trigger.