The first benefit of the Spell Sniper feat says (PHB, p. 170; emphasis mine):
- When you cast a spell that requires you to make an attack roll, the spell’s range is doubled.
Spells: Spiritual Weapon, Bigby's Hand, Mordenkainen's Sword
Which of these spells have their range increased by Spell Sniper, and which ones do not?
Spiritual Weapon says:
When you cast the spell, you can make a melee spell attack [...]
There is the option to make an attack or not, so going by the wording of Spell Sniper, it shouldn't be affected by Spell Sniper because you are not "required to make an attack roll".
Bigby's Hand (Player's Handbook, p. 218) also includes the phrase
you can [...] cause one of the following effects with it.
Beyond that, it also has multiple options that don't include a spell attack at all, so Bigby's Hand shouldn't be affected by Spell Sniper either; even if the wording of "you can make an attack" doesn't do it, the extra options that don't include attacks should still exclude this from Spell Sniper.
Mordenkainen's Sword is the spell that I was looking at that made me ask this question. Unlike the other two, it says:
When the sword appears, you make a melee spell attack against a target of your choice within 5 feet of the sword.
So based off the wording, you have to make an attack against a close enough target. Is that enough to satisfy the requirement of Spell Sniper? I would think that no, it is not intended to be affected by Spell Sniper in any way. The casting range is tied to summoning the sword, the attack is made after being summoned "When the sword appears." and so is not part of the casting itself. A great comparison is Green-Flame Blade where the attack is made "As part of the action used to cast this spell..."
Damaging a target requires an attack roll (as opposed to a saving throw or an automatic hit) so Spell Sniper applies.
For the same reason as Spiritual Weapon.
If the feat were to apply, it should only apply to the Clenched Fist action (the other options do not involve attack rolls) but allowing extra range only for one option of the four available might be unworkable (for example, ruling that you have to bring the hand back within 120ft to use the other options). A GM might rule that the extra range applies to all of the options for ease of play. On the other hand, the spell already has 120 ft range, do you really need any more?
I might rule no on those spells, based on the melee spell attack requirement. When we use the word "sniper" we generally mean soldiers with rifles and crossbows, not clubs and knives. I think the feat should only apply to spells that require a ranged spell attack. That is just my ruling, however, the rules in the book are clear - "When you cast a spell that requires you to make an attack roll," applies to both melee and ranged attacks.
