Fralex
Explorer
Eldritch blast can only target creatures, which can seem a little weird since the description makes it sound like a destructive beam of magical force that damages whatever it hits. I don't foresee any significant game balance problems with allowing the spell to work on inanimate objects, but if you're looking for an in-world justification for the way it works, here's an interpretation I came up with:
Eldritch blast is more like a short-lived curse than a weaponized burst of magic. The energy beam itself does not cause damage; it’s more like a laser sight on a gun that tells the curse which creature to target. The curse instantaneously causes its victims to generate an uncontrollable surge of magical energy, “shocking” themselves with force as if they had tried to cast a spell but it backfired horribly (see also: mishaps in teleportation and using a spell scroll too advanced for you).
Eldritch blast harms creatures but not objects for the same reason a virus can only harm living things; the damage comes from the creature’s own biological processes being turned against it. Or, in the case of undead and constructs, the sustained magical processes that animate them.
I like this take because it fits well with the general witchiness of the warlock class. Blasting your enemies with bolts of power is for sorcerers. Warlock magic is more dark and insidious.
Eldritch blast is more like a short-lived curse than a weaponized burst of magic. The energy beam itself does not cause damage; it’s more like a laser sight on a gun that tells the curse which creature to target. The curse instantaneously causes its victims to generate an uncontrollable surge of magical energy, “shocking” themselves with force as if they had tried to cast a spell but it backfired horribly (see also: mishaps in teleportation and using a spell scroll too advanced for you).
Eldritch blast harms creatures but not objects for the same reason a virus can only harm living things; the damage comes from the creature’s own biological processes being turned against it. Or, in the case of undead and constructs, the sustained magical processes that animate them.
I like this take because it fits well with the general witchiness of the warlock class. Blasting your enemies with bolts of power is for sorcerers. Warlock magic is more dark and insidious.