Is Swift Quiver good enough as is, or should it grant its attacks when cast?

[Segev]

This is inspired by thinking on the spell as discussed (in minor conjunction with others) in shipiazoli's most recent thread. It isbn, however, based on his views of it. Rather, I am thinking about how it is best used in a party, and whether it should be changed to fit what might be its intended roll better.

It is a high-level Ranger spell (first obtainable at level 17) that lets him use his favorite a mousing weapon twice with a bonus action. It requires Concentration and is cast as a bonus action.

Taken in a Ranger design space vacuum, it is best to pre-cast it if you know a battle is imminent so it is active in the first round; otherwise, it does nothing in the round you cast it. As a Concentration spell, it competes with Hunter's Mark, so the Ranger can't do the extra d6 with each attack. Even if he just has Favored Foe, that, too, requires Concentration.

I was going to suggest it is superior as a buff cast on another character, or better yet cast by a Bard who took it as a Magical Secret at level 10, but it does specify that you're transmuting "your quiver" and that its effects allow you to do things on your turns. So that at least is closing a loophole.

Its advantages over Hunter's Mark include being range agnostic and not dependent on neutralizing one target at a time (though that is usually the optimum strategy anyway). It also may be more damage tout two attacks as a bonus action rather than +1d6 damage on two attacks. (This becomes more dubious on round one for a gloomstalker, but that is a somewhat narrow case.)

Still, given its high level and self-buff nature, would it break things to let it not require Concentration and to read, "When you cast this spell and on each of your turns until the spell ends, you can make two...," rather than what it currently reads?

This would allow casting a fifth level Ranger spell to leave Hunter's Mark (or another Concentration effect) in place and to get its benefit on the round it is cast. For a level seventeen feature usable in relatively few encounters, that doesn't seem like too much to me.

Am I wrong?

[GeoffWatson]

Disallow it to be used with tricks like Bard Secrets or Ring of Spell Storing and improving it should be fine.

[BloodSnake'sCha]

I think it is good enough as is, especially with feats like Sharpshooter.
If you care about concentration try to use it with a Glyth of Warding.

[stoutstien]

When looking at spells it's best to break it down into the difference game spaces it's sees. How does it preform in a featless/no multiclass game, how does it interact with one but not the other, and how does it work with both.

SQ is a primary a late game ranger spell and it allows for flexibility of action more than just a static attack count booster. The bonus action attacks are not tied to the attack action so it can work as a reverse mobility spell when nature's veil or vanish aren't applicable. So it comes down to the value of maintaining 2 attacks on top of the freedom of the action. Some rangers are more bonus action hungry than others. You would have to really do a separate rating for each one. For example a hunter could volley + SQ to good effect but the BM would probably gloss right over it unless they are using their pet purely as a meat shield.

For bow bards it is an okay option but it faces stiff competition for those MS picks. Even for weapon using bards ele or holy weapon provide more flexibility and can be upcasted. Past that I think SW is one of the better damage spells the bard can pick up that can serve them well without eating concentration up.

In the end buffing it wouldn't really change the way most people approach it.

[Aett_Thorn]

On a Ranger, I think it's a pretty bad spell. Rangers don't get many "per hit" based abilities that increase their overall damage, except by using Hunter's Mark which competes with SQ. So gaining two extra attacks at level 17 isn't going to bump up their damage a ton. And getting only one or two uses per day, max, just isn't great. Coming at such a high level for Rangers isn't great, but comparing to their other 5th-level spells, it doesn't have a huge amount of competition, and is great if you think the fight is going to last more than a few rounds.

However, I think that the spell is MUCH better on a Bard who poaches it. And even then it's not that great, just possibly thematic as a better version of an Arcane Archer (IMO), and Bards are better able to capitalize on the one great feature that I think the spell has. Namely, the bonus action attacks DON'T require you to take the Attack Action. So you can cast a spell, then bonus action attack. So you can throw out a Shatter or Dissonant Whispers and then shoot twice. Or Disengage, Use an Object, Dash, whatever you want to do for your action, and still be able to attack twice. Or just attack more. Yes, the Ranger can do this, too, but I don't feel like they have as many spell options as Bards do, so lose some of this value.


That said, allowing you to attack twice on the first round of casting really doesn't "fix" the spell as is. Especially for Rangers. As one of their capstone spells, I feel like it should probably still do more. Like the magical ammo doing 2d8+Stat damage on a hit for a bit of an extra bump. And don't have it require Concentration. Even with those changes I don't think that it would be overpowered, even on a Bard who poaches it, considering their other options at that level.

[quindraco]

I think it is good enough as is, especially with feats like Sharpshooter.
If you care about concentration try to use it with a Glyth of Warding.

Depending on what feats you take, it gets worse, not better, compared to other spells you can take. Also, there's no way for a Ranger or Bard to use Glyph of Warding to avoid Concentration, here - you'd need the relevant spells prepared, which neither class has any way to do. You'd have to multiclass into a preparation class and get the spells prepared, which is easy to do for Hunter's Mark but I'm not sure how to get the others - maybe a Ravnica background or Dragonmarked race? Here are the big feats:

DPR for ranger with archery + longbow shooting an AC 19 target, assuming spells are cast the round before:
Base: 14.7
Guardian of Nature: 18.69
Hunter's Mark: 20.3
Favored Foe: 21.9
Swift Quiver: 29.4

I don't have the formula for Piercer, and it's incredibly messy. Leaving it out, here's a more "traditional" approach with feats:
Elven Accuracy, Sharpshooter, Crossbow Expert:
Base: 28.275
Guardian of Nature: 50.06
Favored Foe: 35.7
Swift Quiver: 37.7
Elven Accuracy, Sharpshooter, Gunner:
Base: 22.15
Guardian of Nature: 39.479
Favored Foe: 27.1
Swift Quiver: 44.3

The highest number you see above is with Guardian of Nature, because it helps offset the accuracy penalty from Sharpshooter on top of helping you crit more often. Piercer is weird because you have to guess when to use it, and turns can happen when you never use it because your damage dice are hot. In the real world as you shoot a target you'll get better at predicting when to use Piercer because you will narrow down the target's AC (you should hold onto Piercer longer against a lower AC target, and spend it as soon as you can on a higher AC target). That's pretty hard to express mathematically, and it's nightmare fuel with Hunter's Mark or Favored Foe. Using as a heuristic the average effect Piercer will have on a given die as happening only once (this is incorrect; critting gives you more dice to possibly apply Piercer to), and skipping Favored Foe for sanity, here's a rough approximation of Piercer (I account for the other bullet point, brutal critical, correctly):
Elven Accuracy, Sharpshooter, Crossbow Expert, Piercer (heuristic damage: +0.75 on first hit):
Base: 29.456
Guardian of Nature: 52.306
Swift Quiver: 39.103
Elven Accuracy, Sharpshooter, Gunner, Piercer (heuristic: +1.5):
Base: 23.925
Guardian of Nature: 42.81
Swift Quiver: 47.006

That assumes you use a hand crossbow only for crossbow expert, rather than mixing in a single heavy crossbow shot by dropping your hand crossbow, which will add a small amount of DPR to crossbow expert.

What makes Swift Quiver unforgivable to me is that it's a 5th level spell barely capable of competing with Haste, which is third level. Other spells of noteworthy comparison include Telekinesis at 5th level and Maximilian's Earthen Grasp at second.

A spell probably worthy of being a 5th level Ranger Spell would be this severely upgraded Ensnaring Strike:

Ensnaring Strikes
5th-level conjuration

Casting Time: 1 bonus action
Range: Self
Components: V
Duration: Concentration, up to 1 minute

Each time you hit a creature with a weapon attack before this spell ends, a writhing mass of thorny vines appears at the point of impact, and the target must succeed on a Strength check against your spell save DC or be restrained by the magical vines until the spell ends. A Gargantuan creature has advantage on this check. If the target succeeds on the check, the vines shrivel away. The target can repeat this check as an action on each of its turns; on a success, the target is freed.

As an action, you can cause all of your vines to crush their restrained targets, who must each make a Strength saving throw. Each takes 5d6 piercing damage on a failed save, or half as much damage on a successful one. When a target fails their save, you may choose to render them prone.

[Segev]

A digression on Piercer: Due to the unpredictable nature, a good first-order rule of thumb is to use it on the first die that rolls under half the maximum value it could. If you have multiple in a batch, obviously you want to reroll the lowest that fits this criterion. It is mathematically disadvantageous to reroll anything that rolls more than half the maximum value it could, and I think you statistically break even if you always reroll ones that are exactly half the maximum value.

Now, that's first-order, because you're right: the odds of hitting again in the same round and possibly rolling a lower value than the "just meets the threshold" value you got on the die in the first hit can make it more advantageous to wait and see. But for most humans, "re-roll the first die that comes up under half" is probably sufficient to get a reasonable statistical boost without burning up a lot of brain-cycles trying to get more precise probability calculations.

---

If I'm parsing what I'm reading here correctly, the responses range from, "It's fine, but you probably wouldn't break anything if you did make it lose Concentration and allow the extra attacks as part of the bonus action to cast it," to, "It's underpowered and would be still underpowered even with those changes." There's one comment that it should be somehow protected from Bard-sniping, while others are saying it's not even overpowered on a Bard with the changes proposed.

I do think that the fact that a Bard using Magical Secrets will get more and better use out of it than would a Ranger is a problem, but I also think that removing Concentration is likely going to let the Ranger's mechanisms for improving his per-hit damage (e.g. hunter's mark) maybe pull ahead again.

Am I missing anything in what people have said?

Thanks for the discussion and feedback.

[BloodSnake'sCha]

Depending on what feats you take, it gets worse, not better, compared to other spells you can take. Also, there's no way for a Ranger or Bard to use Glyph of Warding to avoid Concentration, here - you'd need the relevant spells prepared, which neither class has any way to do. You'd have to multiclass into a preparation class and get the spells prepared, which is easy to do for Hunter's Mark but I'm not sure how to get the others - maybe a Ravnica background or Dragonmarked race? .

First, thank you for posting all the math.

I assume mose of the bonus damage from Guardian of Nature is from the advantage it provides. There are a lot of whys in game to generate advantage, I would had put advantage as a different category, I don't think a lot of tables are running solo games.

About the Glyph, their are a lot of ways to get Glyph of Warding. Be it a Magical Secret or the Wish spell or a ring of spell storing(and probably more options I don't think about right now).

In play the other characters can provide a lot of things.
You can even have haste and Swift Quiver and Holy Weapon if your party choose to uberbuff you for a fight.

As their are a lot of whys to buff damage per hit and generate advantage I see increasing the number of attacks as a great thing.

[sithlordnergal]

So, I'd say Swift Quiver is more than good enough, in fact, I'd almost say its too good as written. I wouldn't weaken it, but it certainly doesn't need a buff or anything. Think about it, in exchange for a Bonus Action on the turn you cast it and Concentration, you can make two attacks with your Bonus Action and you'll never run out of ammunition. Even better, you don't need to make an attack action for that bonus action attack, which makes it special since every other Feat and/or ability I can think of that lets you make a bonus action attack requires you to take the Attack action first. That's a powerful spell, and a huge buff for anyone that uses Ranged attacks.

Swift Quiver's issue is that its only available to the two classes that can't really make use of its effect. Think about it, the only two classes that have access to Swift Quiver are the Bard and the Ranger. While both classes can make decent Ranged fighters, you generally won't take them over the Fighter, Rogue, or Warlock. As a result, any ranged build that uses Swift Quiver is going to be more complicated, and potentially even less effective, then other builds simply because you're stuck with getting 10 levels in Bard or 17 levels in Ranger.


And to prove my claim that Swift Quiver is an amazing spell that doesn't need a buff, imagine it on, an Eldritch Knight, Arcane Trickster, or Hexblade Warlock:

On Fighters, it turns you into a literal Machine Gun by giving you two more attacks on a class that generally doesn't have Bonus Actions. Now, obviously the Eldritch Knight could never get it because its a 5th level spell, but lets say they could take it as part of their capstone. At level 20, that Fighter could cast Swift Quiver at the start of the fight, and then they'd get 6 attacks per round. If they really wanted to go nuts, they could Action Surge for a grand total of 10 attacks in one round.


The Warlock is just as crazy with this spell. Given its a 5th level spell, you could take it at level 9. If you're a Blade Pact Hexblade, you'll have access to Eldritch Smite, Improved Pact Weapon, and Thirsting Blade. Improved Pact Weapon gives you access to Longbows for your Pact Weapon, so you'll be able to use Charisma for all your attacks. Thirsting Blade essentially gives you Extra Attack, so you'll be able to attack up to 4 times when you have it and Swift Quiver. And finally, Eldritch Smite will let you Smite on all four of those ranged attacks. Then, at level 12, you can take Lifedrinker to essentially double the damage from your Charisma Modifier with all four attacks

But wait, there's MORE good news for the Warlock. Because of the wording of Swift Quiver and Lifedrinker, you don't even NEED to use your action on the Attack Action. As soon as you hit level 17, you can cast Eldritch Blast then do the two Bonus Action attacks for 6 attacks in a round. And since Lifedrinker only requires you to hit a creature with your Pact Weapon to work, the two attacks from Swift Quiver still gain all of its benefits. You basically gain the same number of attacks as the fighter.


Now, you'd think that the Arcane Trickster is the odd man out since Swift Quiver and Cunning Action are both Bonus Actions. However, that's where you'd be wrong. Since Swift Quiver doesn't need you to make an Attack in order to use its Bonus Action, that means your Action is free to be used as you wish. You could easily use your Action to Hide/Dash/Disengage/ect., then use your Bonus Action to make two attacks instead of just one. We already know how useful having a second attack is on a Rogue, now imagine having two attacks on a Rogue without losing your Cunning Action.

EDIT: And do note, the three above scenarios, while impossible, were all without feats. Toss Sharpshooter and/or Crossbow Expert on top of that and now you have a Fighter or Warlock that can make 6 attacks per round at level 20, all of which can deal an additional 10 points of damage, and if you use the Heavy Crossbow, which you'd want to since the Bonus Attack with a Hand Crossbow is pointless with Swift Quiver, all of those attacks will have a base damage of 1d10.

[Protolisk]

The Warlock is just as crazy with this spell. Given its a 5th level spell, you could take it at level 9. If you're a Blade Pact Hexblade, you'll have access to Eldritch Smite, Improved Pact Weapon, and Thirsting Blade. Improved Pact Weapon gives you access to Longbows for your Pact Weapon, so you'll be able to use Charisma for all your attacks. Thirsting Blade essentially gives you Extra Attack, so you'll be able to attack up to 4 times when you have it and Swift Quiver. And finally, Eldritch Smite will let you Smite on all four of those ranged attacks. Then, at level 12, you can take Lifedrinker to essentially double the damage from your Charisma Modifier with all four attacks

But wait, there's MORE good news for the Warlock. Because of the wording of Swift Quiver and Lifedrinker, you don't even NEED to use your action on the Attack Action. As soon as you hit level 17, you can cast Eldritch Blast then do the two Bonus Action attacks for 6 attacks in a round. And since Lifedrinker only requires you to hit a creature with your Pact Weapon to work, the two attacks from Swift Quiver still gain all of its benefits. You basically gain the same number of attacks as the fighter.

Specifically, Eldritch Smite is only usable once per turn. Even more, you probably could only use it once per short rest at level 9 anyway since you needed to spend one slot to even use Swift Quiver, and you only have 2 slots at level 9.

As for the rest, yeah that tracks. Though I'd argue Shadow of Moil is stronger for specialized use cases like the PAM Hexblade, the rest does show how strong the spell can be.

If there was an "Arcane Archer" styled Patron that provided a Warlock with it as an expanded spell list, I could be convinced of its power.

[Segev]

So, I'd say Swift Quiver is more than good enough, in fact, I'd almost say its too good as written.

(...)

Swift Quiver's issue is that its only available to the two classes that can't really make use of its effect.

(...)

And to prove my claim that Swift Quiver is an amazing spell that doesn't need a buff, imagine it on, an Eldritch Knight, Arcane Trickster, or Hexblade Warlock.

But...you defeat your own argument, here: it is NOT available to anybody but the Ranger and, through Magical Secrets, the Bard. It doesn't matter how amazing it would be with any other class, unless you're going to multiclass to get them. If you do, you're either going Bard 10 before multiclassing or you're going Ranger 17 before multiclassing. You're never getting the third attack as a fighter, certainly not the fourth attack.

A bard/Warlock could have this 5th level spell with Pact Magic 5th level slots at level 19, but by then I hardly think it's amazing. That's actually 1/3 of my problem with it: for a spell designed to be taken at level 17+, it isn't actually that great and it has too much wind-up time.

It doesn't matter what you "could" do "if" it were on another class's list, only what you CAN do with it. The fact that it's a 5th level spell exclusive to the Ranger spell list is highly relevant to its balance. Dipping some levels of rogue after Ranger 17 or Bard 10 in order to...not use Cunning Action because we get two attacks off of swift quiver isn't that hot, especially since a well-chosen Bard subclass or just having the Ranger's Extra Attack you get on the way to Ranger 17 will get you two attacks off the attack action, so just having Cunning Action lets you do hide/dash/disengage as a bonus action without wasting a 5th level spell slot on it.

The spell should be balanced for being a 5th level Ranger spell, with consideration given to the fact that, ironically, a Bard will have it 7 levels earlier if he wants it.

I remain of the opinion that having it worded thusly would be ideal:

Swift Quiver
5th-level transmutation
Casting Time: 1 bonus action
Range: Touch
Components: V, S, M (a quiver containing at least one piece of ammunition)
Duration: 1 minute
You transmute your quiver so it produces an endless supply of nonmagical ammunition, which seems to leap into your hand when you reach for it.

When you cast this spell and on each of your turns until the spell ends, you can use a bonus action to make two attacks with a weapon that uses ammunition from the quiver. Each time you make such a ranged attack, your quiver magically replaces the piece of ammunition you used with a similar piece of nonmagical ammunition. Any pieces of ammunition created by this spell disintegrate when the spell ends. If the quiver leaves your possession, the spell ends.

[sithlordnergal]

But...you defeat your own argument, here: it is NOT available to anybody but the Ranger and, through Magical Secrets, the Bard. It doesn't matter how amazing it would be with any other class, unless you're going to multiclass to get them. If you do, you're either going Bard 10 before multiclassing or you're going Ranger 17 before multiclassing. You're never getting the third attack as a fighter, certainly not the fourth attack.

A bard/Warlock could have this 5th level spell with Pact Magic 5th level slots at level 19, but by then I hardly think it's amazing. That's actually 1/3 of my problem with it: for a spell designed to be taken at level 17+, it isn't actually that great and it has too much wind-up time.

It doesn't matter what you "could" do "if" it were on another class's list, only what you CAN do with it. The fact that it's a 5th level spell exclusive to the Ranger spell list is highly relevant to its balance. Dipping some levels of rogue after Ranger 17 or Bard 10 in order to...not use Cunning Action because we get two attacks off of swift quiver isn't that hot, especially since a well-chosen Bard subclass or just having the Ranger's Extra Attack you get on the way to Ranger 17 will get you two attacks off the attack action, so just having Cunning Action lets you do hide/dash/disengage as a bonus action without wasting a 5th level spell slot on it.

The spell should be balanced for being a 5th level Ranger spell, with consideration given to the fact that, ironically, a Bard will have it 7 levels earlier if he wants it.

I remain of the opinion that having it worded thusly would be ideal:

Swift Quiver
5th-level transmutation
Casting Time: 1 bonus action
Range: Touch
Components: V, S, M (a quiver containing at least one piece of ammunition)
Duration: 1 minute
You transmute your quiver so it produces an endless supply of nonmagical ammunition, which seems to leap into your hand when you reach for it.

When you cast this spell and on each of your turns until the spell ends, you can use a bonus action to make two attacks with a weapon that uses ammunition from the quiver. Each time you make such a ranged attack, your quiver magically replaces the piece of ammunition you used with a similar piece of nonmagical ammunition. Any pieces of ammunition created by this spell disintegrate when the spell ends. If the quiver leaves your possession, the spell ends.

That's fair, since it is only on the Ranger's spell list it should be balanced towards that. Though keep in mind, since its a 5th level spell it can be put into a Ring of Spell Storing for Fighters, Warlocks, and Rogues to use. Either way, I don't think allowing you to make the bonus action attack on the same turn you cast it would be enough to improve it for the Bard or Ranger. In order to really improve the spell, you'd need to change one of two things:

1) Make it a buff spell. Change the sentence "You transmute your quiver so it produces an endless supply of nonmagical ammunition..." to "You transmute a quiver so it produces an endless supply of nonmagical ammunition...". Now you can give it to your allies and buff them, allowing those who can make better use of the spell to use it.

2) Buff the and Ranger a bit. Give them both something to increase their damage whenever they successfully hit something. For example, remove the Once Per Turn limit on College of Swords Flourish abilities, or allow the Hunter Ranger to apply Colossus Slayer to all attacks. Basically, give them something that puts them on par with the Rogue or Warlock damage wise.

Otherwise you'll need to add some sort of bonus damage to the spell itself in order to improve the mediocre damage that Rangers and archer Bards deal with their Extra Attack. Because honestly, the spell itself isn't the problem, its the fact that the two classes that get it lack any way to improve the damage they deal with Extra Attack.

[Segev]

I should point out I also removed Concentration from this version of Swift Quiver. It can be used a on side Hunter's Mark or Flame Arrows now.

[gooch]

I have no high level Ranger experience, so just kind of spitballing...
What happens if you flavour it as an LMG type ability? Bonus action cast, no concentration, but you lose the attacks on any round where you move. Maybe buff it a bit, or reduce the movement requirement... You can only move half speed if you want the extra attacks?
Also, would moving the attacks from bonus action to the main action help? Stacking with extra attack, obviously. Again, no level 17 Ranger experience, so no idea if opening up the bonus action on subsequent rounds is that useful.

Edit - the second one seems like it would buff those thieving Bardstards more than Rangers. That might be counter to the goal

[Kane0]

The Ranger really suffers with the amount of Conc spells to choose from, removing Conc and allowing it to be shared to someone else I think is enough.
At best if you really wanted to get the BA attacks when you cast it i’d say one instead of both on that turn when you cast the spell.

Edit: Flame arrows shouldnt he conc either, its already limited enough by cast time, duration and number of arrows… would at least make it a viable higher level alternative to HM

[Eldariel]

Let's see:
1) It competes with CBE for bonus action attack.
2) It adds extra attacks on top of attacks instead of adding damage.
3) It takes a round of wind-up time.
4) It only lasts 1 encounter

All of these lead me to conclude that not only is it bad, it's just ridiculously bad. "6 attacks!" doesn't mean anything. The more attacks you have, the less you care about more attacks: what you want is damage to add on each of those attacks. On a Fighter 20, Holy Weapon and Elemental Weapon are both much better. DPR vs. AC 20 with only 4 Sharpshooter attacks at +13 (Archery style + 5 Dex + 6 Prof) is 67 DPR. Going up from 4 attacks to 6 is a 50% increase in damage (100 DPR). Going up from 1d6+15 damage to 1d6+2d8+15 (Holy Weapon) nets the same damage increase, makes your bow magical, lets you hit some key vulnerabilities, and lasts an hour instead of a minute and is usable on round 1 instead of only from round 2 onwards. Holy Weapon is thus the better spell (unless running out of arrows is somehow a relevant consideration on level 20). Especially the fact that Swift Quiver does nothing on round 1 and the fact that Swift Quiver lasts 1 minute (1 fight generally) while Holy Weapon lasts 1 hour (easily multiple fights or a long dungeon run) together make it just plain better.

Level 5 Elemental Weapon loses out to this a bit since the target AC is low relatively speaking compared to the hit bonus (89 DPR) but it has the same benefits as Holy Weapon (lasts an hour), and it has the option of upcasting to 7 (though even then it doesn't actually beat the others vs. AC 20 by much but against higher AC targets it wins out). And both Elemental Weapon and Holy Weapon can combine with Crossbow Expert to instead gain 5 attacks adding ~25% to their damage output while Swift Quiver is capped out: there's nothing more to be done. So on a level 20 Fighter, Swift Quiver is trivially the worse spell. 1 minute vs. 1 hour, less damage, 1st round sucks, etc.

[Segev]

Let's see:
1) It competes with CBE for bonus action attack.
2) It adds extra attacks on top of attacks instead of adding damage.
3) It takes a round of wind-up time.
4) It only lasts 1 encounter

All of these lead me to conclude that not only is it bad, it's just ridiculously bad. "6 attacks!" doesn't mean anything. The more attacks you have, the less you care about more attacks: what you want is damage to add on each of those attacks. On a Fighter 20, Holy Weapon and Elemental Weapon are both much better. DPR vs. AC 20 with only 4 Sharpshooter attacks at +13 (Archery style + 5 Dex + 6 Prof) is 67 DPR. Going up from 4 attacks to 6 is a 50% increase in damage (100 DPR). Going up from 1d6+15 damage to 1d6+2d8+15 (Holy Weapon) nets the same damage increase, makes your bow magical, lets you hit some key vulnerabilities, and lasts an hour instead of a minute and is usable on round 1 instead of only from round 2 onwards. Holy Weapon is thus the better spell (unless running out of arrows is somehow a relevant consideration on level 20). Especially the fact that Swift Quiver does nothing on round 1 and the fact that Swift Quiver lasts 1 minute (1 fight generally) while Holy Weapon lasts 1 hour (easily multiple fights or a long dungeon run) together make it just plain better.

Level 5 Elemental Weapon loses out to this a bit since the target AC is low relatively speaking compared to the hit bonus (89 DPR) but it has the same benefits as Holy Weapon (lasts an hour), and it has the option of upcasting to 7 (though even then it doesn't actually beat the others vs. AC 20 by much but against higher AC targets it wins out). And both Elemental Weapon and Holy Weapon can combine with Crossbow Expert to instead gain 5 attacks adding ~25% to their damage output while Swift Quiver is capped out: there's nothing more to be done. So on a level 20 Fighter, Swift Quiver is trivially the worse spell. 1 minute vs. 1 hour, less damage, 1st round sucks, etc.

Remembering that this is a Ranger spell, and despite the targeting being "one quiver" only affects the caster's ability to make attacks, does this change your analysis much?

I do agree with most of the issues you raise in your list, primarily point 3. I seek to address point 1 by removing the Concentration requirement, which enables choices of damage-adding spells to be added on, and point 3 by letting you get the extra attacks as part of the bonus action to cast the spell. I think removing Concentration from this and flame arrows so that a ranger could have hunter's mark, flame arrows, and swift quiver active simultaneously at level 17+ would make swift quiver a definitely-worthwhile 5th level Ranger spell.

I understand the urge to make it a buff spell you can share out, but I think its purpose is to be a self-buff, a "special technique" in spell form.

Competing with Crossbow Expert for bonus action attacks - thus making it only +1 attack if you have that feat - is a challenging flaw to deal with, because Crossbow Expert is not something you can guarantee all Rangers will have. I think it may have to be left as-is for that, with its advantageous ability to make the two bonus action attacks even if no other attacks are made as a small consolation.

The duration is another point I find worth consideration. If it were upped to an hour, it could conceivably not need to grant its extra attacks as part of the bonus action used to cast it. Heck, it wouldn't even really need to be less than an action to cast it at that point. I'm not sure what combination of adjustments I think "feels" best, here, though.

[quindraco]

Let's see:
1) It competes with CBE for bonus action attack.
2) It adds extra attacks on top of attacks instead of adding damage.
3) It takes a round of wind-up time.
4) It only lasts 1 encounter

All of these lead me to conclude that not only is it bad, it's just ridiculously bad. "6 attacks!" doesn't mean anything. The more attacks you have, the less you care about more attacks: what you want is damage to add on each of those attacks. On a Fighter 20, Holy Weapon and Elemental Weapon are both much better. DPR vs. AC 20 with only 4 Sharpshooter attacks at +13 (Archery style + 5 Dex + 6 Prof) is 67 DPR. Going up from 4 attacks to 6 is a 50% increase in damage (100 DPR). Going up from 1d6+15 damage to 1d6+2d8+15 (Holy Weapon) nets the same damage increase, makes your bow magical, lets you hit some key vulnerabilities, and lasts an hour instead of a minute and is usable on round 1 instead of only from round 2 onwards. Holy Weapon is thus the better spell (unless running out of arrows is somehow a relevant consideration on level 20). Especially the fact that Swift Quiver does nothing on round 1 and the fact that Swift Quiver lasts 1 minute (1 fight generally) while Holy Weapon lasts 1 hour (easily multiple fights or a long dungeon run) together make it just plain better.

Level 5 Elemental Weapon loses out to this a bit since the target AC is low relatively speaking compared to the hit bonus (89 DPR) but it has the same benefits as Holy Weapon (lasts an hour), and it has the option of upcasting to 7 (though even then it doesn't actually beat the others vs. AC 20 by much but against higher AC targets it wins out). And both Elemental Weapon and Holy Weapon can combine with Crossbow Expert to instead gain 5 attacks adding ~25% to their damage output while Swift Quiver is capped out: there's nothing more to be done. So on a level 20 Fighter, Swift Quiver is trivially the worse spell. 1 minute vs. 1 hour, less damage, 1st round sucks, etc.

On top of all this, by the way, it manifests ammunition in the quiver, not in the weapon, and mandates a quiver - it doesn't work on crossbows, slings, or blowpipes. If it worked like the Artificer infusion and loaded the weapon for you, while ignoring ammunition type, it would enable Hand Crossbow + Shield, which would be something, since you can dodge and take your two SQ shots. It does not do this.

If you tasked me with fixing Swift Quiver, I would do this, in priority order:

1. Swift Quiver is not restricted to only arrows - it is rewritten to work with any ammunition weapon.
2. Swift Quiver targets an ammunition weapon, not an ammunition container, reloading it for you, so slings, hand crossbows, and if you're playing with them, pistols now work with shields. Since the weapon is reloaded, this also lets you ignore Loading.
3. Swift Quiver targets yourself, not the weapon, so for the duration, any weapon you fire reloads itself.
4. Swift Quiver grants +2 to Extra Attack instead of 2 bonus action attacks. At this point, the spell is performing about as well as a third level spell should, and isn't significantly worse than Haste (which can buff other party members instead of the caster, and so usually works the round it's cast).
5. The conjured ammunition counts as magical silvered adamantine.
6. Swift Quiver is duration 1 hour. At this point, the spell is performing about as well as a fourth level spell should, and isn't significantly worse than Guardian of Nature.
7. Getting up to level 5 parity (Holy Weapon, Telekinesis, Maelstrom, etc) requires additional effects, and you could choose several different ones depending on design intent. I personally like copying Holy Weapon for this:
8. 1. Replace Holy Weapon's emitted light (worse for stealth, better for helping the entire party see) with darkvision with a range equal to the long range of one ranged weapon you are wielding.
   2. Replace the bonus action dismissal burst of light with one of antisound: the damage type is Thunder, and targets who fail their save are rendered Deaf and Mute, as if their heads are wrapped in a Silence bubble.

[Segev]

On top of all this, by the way, it manifests ammunition in the quiver, not in the weapon, and mandates a quiver - it doesn't work on crossbows, slings, or blowpipes. If it worked like the Artificer infusion and loaded the weapon for you, while ignoring ammunition type, it would enable Hand Crossbow + Shield, which would be something, since you can dodge and take your two SQ shots. It does not do this.

If you tasked me with fixing Swift Quiver, I would do this, in priority order:

1. Swift Quiver is not restricted to only arrows - it is rewritten to work with any ammunition weapon.
2. Swift Quiver targets an ammunition weapon, not an ammunition container, reloading it for you, so slings, hand crossbows, and if you're playing with them, pistols now work with shields. Since the weapon is reloaded, this also lets you ignore Loading.
3. Swift Quiver targets yourself, not the weapon, so for the duration, any weapon you fire reloads itself.
4. Swift Quiver grants +2 to Extra Attack instead of 2 bonus action attacks. At this point, the spell is performing about as well as a third level spell should, and isn't significantly worse than Haste (which can buff other party members instead of the caster, and so usually works the round it's cast).
5. The conjured ammunition counts as magical silvered adamantine.
6. Swift Quiver is duration 1 hour. At this point, the spell is performing about as well as a fourth level spell should, and isn't significantly worse than Guardian of Nature.
7. Getting up to level 5 parity (Holy Weapon, Telekinesis, Maelstrom, etc) requires additional effects, and you could choose several different ones depending on design intent. I personally like copying Holy Weapon for this:
8. 1. Replace Holy Weapon's emitted light (worse for stealth, better for helping the entire party see) with darkvision with a range equal to the long range of one ranged weapon you are wielding.
   2. Replace the bonus action dismissal burst of light with one of antisound: the damage type is Thunder, and targets who fail their save are rendered Deaf and Mute, as if their heads are wrapped in a Silence bubble.

Swift quiver already works for any kind of ammunition. Nothing says a quiver can't have bolts or sling bullets in it. The "Loading" trait does make it next to useless, though, so having the spell explicitly allow you to ignore that would not be a bad idea.

Keeping it focused on being about the quiver is important, I think, so I wouldn't have it grant darkvision or anything like that. Rather than have it count as specially magical, silver, or adamantine, I would have it able to copy any ammunition in the quiver. So if you have a super-awesome legendary one-shot piece of ammo, you now can use it as many times as you like as long as you use this spell, first. If you have a quiver with different specialized ammo, you can pick between them as long as you have at least one ammo of the sort you want in there.

I actively dislike making it +2 attacks on Extra Attack. Two attacks on a bonus action creates more interesting gameplay choices about what to do with your normal action.

[Valmark]

On top of all this, by the way, it manifests ammunition in the quiver, not in the weapon, and mandates a quiver - it doesn't work on crossbows, slings, or blowpipes. If it worked like the Artificer infusion and loaded the weapon for you, while ignoring ammunition type, it would enable Hand Crossbow + Shield, which would be something, since you can dodge and take your two SQ shots. It does not do this.

Note that this isn't required- "Each time you make such a ranged attack, your quiver magically replaces the piece of ammunition you used with a similar piece of nonmagical ammunition" can also be red as it substituting it already in the crossbow or whatever (which was in fact how I thought it was red until I saw this post).

[Zalabim]

About the Glyph, their are a lot of ways to get Glyph of Warding. Be it a Magical Secret or the Wish spell or a ring of spell storing(and probably more options I don't think about right now).

In play the other characters can provide a lot of things.
You can even have haste and Swift Quiver and Holy Weapon if your party choose to uberbuff you for a fight.

As their are a lot of whys to buff damage per hit and generate advantage I see increasing the number of attacks as a great thing.

Swift Quiver and Holy Weapon aren't eligible to be put into a spell Glyph of Warding in any way. They target an object, not a creature or area.

[BloodSnake'sCha]

Swift Quiver and Holy Weapon aren't eligible to be put into a spell Glyph of Warding in any way. They target an object, not a creature or area.

I never noticed the fact that Swift Quiver have a range of touch and not self.