Would cloud of knives ruin invisibility?

[Hiro Quester]

Making a Sorcerer/Swiftblade/Unseen Seer, using Hunter's Eye for Sneak attacks.

Considering a persistent cloud of knives, for free action sneak attack each round. But thinking about the interaction with spells like greater invisibility.

Would the knives be visible, outlining the location of the invisible character? Or would they count as things you carry that goes invisible with you?

I'm sure this is probably "DM's call". But how would you rule this? What are the best arguments for each interpretation?

[Nifft]

I think it's a DM's call if stuff like Cloud of Knives or Luminous Armor goes invisible with you.

But even if the cloud did give away your square, you'd still be invisible -- so it's still a 50% miss chance unless they can negate that separately.

[XionUnborn01]

Probably DM call by RAW, but I would say that the knives were visible unless you used invisible spell metamagic.

[TalonOfAnathrax]

Well it's a spell cast on you, and you're invisible... So it should be invisible too, right?

[SangoProduction]

Would a Mage Armor ruin invisibility?

[Diarmuid]

Would a Mage Armor ruin invisibility?

I'm not really sure you're working with apples to apples there:

"An invisible but tangible field of force surrounds the subject of a mage armor spell"

vs

"You conjure a cloud of sharp knives around you. The knives float in the air around your upper body, pointing in the direction you look."

I think a better question would be whether something like Fire Shield or Entropic Shield would be visible on someone under the effects of an Invisibility spell.

[Nifft]

Would a Mage Armor ruin invisibility?

Um... did you check if mage armor is itself visible?

[BassoonHero]

It seems to me that the knives should be treated like a spell effect. If they are, then they do not become invisible. The caster would still be invisible and have full concealment. Anyone who can see the knives can target the correct square automatically and would roll a 50% miss chance as normal. I would rule the same for Fire Shield and Entropic Shield.

Personally, I'd be content to simply add "Effect" and "Target" entries to a giant list of spells.

[Thurbane]

This has got me wondering now...how about Ioun Stones? An animated shield?

[Hiro Quester]

See, I always assumed that ioun stones were part of your gear, and would go invisible with you.

On that logic (yes... I know, but still) your cloud of knives should be invisible until you release one. An animated shield would be similar.

It depends how far away from you your invisibility extends. Invisibility spell says:

Any part of an item that the subject carries but that extends more than 10 feet from it becomes visible

I'd use that to argue that a could of knives (also ioun stones, animated shield) that does not extend more than 10 feet from you would be invisible too.

[Mordaedil]

I keep thinking cutting the ropes on a bridge would count as an attack and keep avoiding doing such aggressive actions, but it does actually say in the spell description that it can be done.

Seems strange to me, but I think that means something like cloud of knives would work fine as you aren't directly attacking, but the enemy is essentially bumping into you.

Or if it dispels, I'd be really curious about the exact metagame nature of the magic.