Cordon of arrows

[iTreeby]

When you cast cordon of arrows, do all the pieces of ammunition need to be in the same spot? If they don't need to be, can the same enemy be hit with more than one cordon arrow? Is this spell only for protecting the camp while everyone is asleep?

[Vogie]

When you cast cordon of arrows, do all the pieces of ammunition need to be in the same spot?
You are planting the pieces "within Range", and it has a Range of 5 feet. That location is the center of the 30 ft radius zone.


If they don't need to be, can the same enemy be hit with more than one cordon arrow?
Any enemy will get hit when it enters the above-mentioned zone OR ends their turn in that zone. If they hang around, and fail Dex saves, then yes, they can get hit by multiple arrows.


Is this spell only for protecting the camp while everyone is asleep?
With an 8 hour duration, it is certainly able to be used for keeping a camp protected. You could also:

Use it to set a trap, such as planting the arrows in the ground inside a bush next to a road, or under a table in an inn.
Use it to make an enemy think your archer is in a different position, or multiple places at once.
I've used it on telekinetic characters, who cast it at the beginning of the fight. Instead of "planting" the arrows, I refluff it by having the arrows remove themselves from the quiver and float above the character's head at that spot.

I have also used the mechanic of Cordon of Arrows to mechanically represent NPC guards from the above wall shooting down to targets surrounding the party on the ground.

[ImproperJustice]

Our ranger has used it frequently at the start of a fight to make his position a little more secure.

[krugaan]

Seems like it would good for ambushes.

After all, it's not concentration, so you could theoretically stack as many as you have slots for.

One of the few spells that really allow you to do that.

[Citan]

1. When you cast cordon of arrows, do all the pieces of ammunition need to be in the same spot? 2. If they don't need to be, can the same enemy be hit with more than one cordon arrow? 3. Is this spell only for protecting the camp while everyone is asleep?
1. All neet to be put within 5 feet from the place you are standing on when casting the spell.
2. While they need to be, you can perfectly make it so that a single enemy quickly suffers several arrows, since the activation range is 30 feet. See below.
3. Nope, not at all, see below.

Seems like it would good for ambushes.

After all, it's not concentration, so you could theoretically stack as many as you have slots for.

One of the few spells that really allow you to do that.
More precisely, using the facts that...
1) It's 8 hour long (or 16 if multiclassed Sorcerer)
2) It's 30 range feet of activation
3) When casting "you can designate any creatures you choose, and the spell ignores them. "
Note on that last point that the way of designation is as vague as one could try to make it: no "you can see" clause, no "in X feet range" clause, no "that you know" clause etc.
Technically, there is no way to clearly know what would be RAW from what would not. It seems that you can only "describe who", and there is no indications on how to restrict that either.

So while the obvious is designating your party ("all my friends" or "all creatures around me") would work fine, I don't see any sensible reason for a DM to refuse descriptions akin to, for example, a specific creature ("all humans") or a list of people that may be miles away.

My only limit personally, as a DM, would be denying any description that does not refer solely on physical / visual characteristics or precise knowledge on your part.
For example, "all humanoid-looking creatures" would (probably, although not really sure) roll by me, but not for example...
1. "all my friends": I know "it's magic", but how is the trap supposed to know whichever creature is friendly to you? And what happens with changing relationship? Although this could certainly allow clever traps, like setting up "insurance" cordons in case of dangerous negotiations. XD

2. "Every person related to Duke XXX": unless you as a character can demonstrate to me you actually have a precise and complete knowledge of every such person (which is mathematically impossible because "related" is too vague -"blood-related" could work though), probably with a relevant DC, this wouldn't be allowed.

Anyways...
Let's put aside the "how far ignorance can go" discussion, let's consider the classic "everyone in my party -companions/pets/conjurations included- is ignored".

Interesting things to do.
- Camp protection: obvious one.
- Entry guard: derivation of the first, works well in dungeons: since it takes only an action, in only one minute you can set up at least 5 sets of arrows in half-circle around a door, with possibly caltrops or furniture to hamper movement.
- "Protection Circle": same idea of half-circle set up a while before attacking enemy camp to have a way to disturb/slow down enemy chasers if you have to flee.
- Distraction: like someone said above, set up quickly then move away to lure an enemy in another direction.
- Flushing out: position an arrow in such a way that a creature would always be targeted unless it moves frankly out of its cover.

Great things to do with proper build (Bard with Magic Secrets, multiclass Warlock or Extend Sorcerer) / ally (anyone with either ways to stop enemy somewhere or great speed and grapple): draw and stick enemies into a loaded spot with Grapple+(Cunning Action|Step of The Wind|Fly) or Shove+(Spirit Guardians|Spike Growth|Plant Growth).

It's certainly a very costly way to set up nova damage, so I wouldn't recommend using it on a classic Ranger (you have much better uses for spell slots usually) but with a trap build that has lots of slots, it can be a great occasional trick. :)