Polymorph – a spell to go ape over?

A single casting of true polymorph is probably worth half a kingdom, if not more. With the addition of the mighty Zodar to 5e, it is the strongest spell in the entire game. This article is dedicated to its solid but overrated younger brother, polymorph. It’s called the best healing spell in the game and showered with praise all around. In this article, I will talk about the effectiveness of polymorph.

What does the spell do?

4th-level transmutation, available to wizards, bards, sorcerers, druids and Trickery clerics. You can get it on a warlock if you take the Sculptor of Flesh invocation(don’t do this). Transform the target into a beast with a CR up to its level(or CR, if polymorphing an NPC).

Concentration, lasts up to 1 hour. The target reverts to its original form if reduced to 0 hit points, any excess damage spills over into that form.

An unwilling target can make a Wisdom saving throw to resist the effect, succeeding automatically if it is a shapechanger.

For the sake of keeping the list short, I will assume that you are transforming an ally into something of CR 7 or higher. Therefore, our list of options is:

• T-Rex
• Sperm Whale
• Huge Giant Crab
• Giant Ape

Each of these creatures will be evaluated against a “training dummy” equivalent to a CR 7 monster per the DMG monster creation guidelines – 16 AC, +6 to hit, 45 damage if all attacks hit.

Calculating Effective HP

A creature’s expected damage with an attack is equal to the average damage dealt on a hit multiplied by its chance to hit.

Effective hit points are a term used to convert a creature’s AC and HP into a single number for ease of comparison. In order to get that number, we divide the creature’s hit points by the accuracy of the attacker.

For our example, we have selected a monster with +6 to hit. Therefore, a hypothetical monster with 100 hit points and 12 AC has 100/0.75 = 133.33 effective hit points, whereas one with 50 hit points and 19 AC has 50/0.4 = 125 effective hit points.

Tyrannosaurus Rex

24.8 damage with its bite, or 30.9 if it has advantage after the first bite restrains its target. The tail targets a different creature, dealing an average of 15.4 damage.

Against a foe with +6 to hit, 13 AC with 136 HP amounts to 194.3 effective HP, equivalent to 97.15 HP on a 17 AC character or 77.7 on a 19 AC character.

Sperm Whale

32 DPR and a chance to swallow the target if it hits with its bite, dealing 1d6 acid damage every turn. 189 HP with 13 AC amounts to 261 effective HP, equivalent to 130 HP on a 17 AC character or 104 on a 19 AC character.

120ft. Blindsight.

The obvious downside is that it’s unable to move on land, so it’s only actually going to fight underwater. That said, it’s described as being 70 feet long and it’s Gargantuan, so you’d be placing down a 14×4 slab of meat on the battlefield. It might even eat two rounds of enemy attacks, and because of its sheer size using it as total cover is not unimaginable.

Huge Giant Crab

18.9 DPR with a grapple. 161 HP with 15 AC amounts to 268.3 effective HP, or 134.2 on a 17 AC character, 107.3 on a 19 AC one.

30ft. Blindsight.

This is probably the best polymorph option available, because the spell is better used as an emergency pseudo-heal than a discount damage option, and as such having decent AC for a beast and a +5 bonus to saving throws to maintain concentration on spells is more valuable than having good DPR in melee.

Giant Ape

Everyone’s favorite monkey. 31.5 DPR in melee, 21.4 at range. 157 HP with AC 12 amounts to 209 effective HP, equivalent to 104.7 HP on a 17 AC character or 83.7 on a 19 AC character.

When should I cast the spell?

You have two real options – precast the spell before entering combat or cast it on an ally who is about to go down.

Opening with Polymorph

You’ve decided to precast polymorph on a friend, giving them a large pile of ablative hit points. While these hit points remain, their AC and mental saving throws are thrown in the garbage and they’re kind of locked into going into melee to deal damage.

This is clearly an offensive use of the spell rather than a defensive one – your choice of target was not based on the fact a specific ally is in danger, since you cast it before the encounter began. Who should you choose as the spell’s target?

If you target a caster, that caster is going to have a harder time maintaining concentration on any spells of their own and will be unable to cast any more spells while the spell remains in effect. If you target a martial, they are (hopefully) capable of dealing more damage than the creature you’re turning them into.

Let’s take a level 7 variant human fighter. No subclass, just Crossbow Expert, Archery and Sharpshooter with 18 Dex. That’s 25 at-will damage against an AC 16 monster. Turning this fighter into a giant ape is a net damage increase of +6.5 in melee, but a -3.6 decrease at range(also the range is worse).

If we’re looking to use this spell offensively, our best option will be to transform a fullcaster who isn’t a Warlock. Someone whose best offensive cantrip is doing 2d8 or so on a hit now. Someone who’s probably better off doorway dodging or just dodging while concentrating on a better spell of their own.

Emergency Polymorph Button

Oh no, someone’s about to die… should I do something about it? You’re in combat and your actions/bonus actions are very finite – the answer to that question depends entirely on how much your party’s survival hinges on the endangered character.

Bear in mind that if said PC is concentrating on an essential spell, like a hypnotic pattern thanks to which four cyclops aren’t hammering your party with blows right now, polymorph will make them far more likely to break concentration.

A dodging 19 AC fullcaster with 1 HP remaining takes 6.25 attacks at +6 to hit to bring down, if they cast shield then that number rises to 44.4.

• Huge giant crab, 15 AC/+5 Con: 8.33 +6 to hit attacks required on average to force a DC 10 save failure, 13.9 while dodging
• Optimized fullcaster, 19 AC/+3 Con and War Caster: 27.78 +6 to hit attacks needed on average to force a DC 10 save failure, or 69.44 while dodging

So the shield spell on that caster would buy them 38.15 more attacks before they are downed, whereas polymorph into the best concentration-protection form buys them 7.05 attacks before breaking concentration.

Let’s also note that a giant ape’s 209 effective HP is equivalent to 33 HP on a dodging 19 AC fullcaster – turning them into a monkey is worth +11 HP over an upcast cure wounds.

So polymorph is not all that helpful to save someone concentrating on a key spell – who else can we use it on?

• Casters not concentrating on anything right now? They’re most likely just yeeting cantrips for 2d8 damage or so. Your precious 4th-level spell slot doesn’t need to be spent on saving them right now, a healing word used by you or a friend at the end of the encounter will suffice.
• Martials, Rangers etc. dealing a significant amount of damage? The damage that makes them so essential is probably a good deal better than what your emergency beast form can offer. Perhaps a healing word cast after they drop would be a better use of a spell slot.

Utility?

Your options with this spell are just beasts. The utility they offer is nothing earth-shattering:

• Flight. A flying speed is awesome because you can throw magic stone rocks at the enemy from above until they die while they can’t hit you back with their melee weapons. A polymorphed ally can also serve as a mount for your party – however, do note that the highest-CR flying beast is CR 2 and you could just summon it with conjure animals.
• Burrowing. In many cases it’s flying but better. Actually a decent way to protect an allied caster’s concentration if you turn them into a giant badger and they hide underground for total cover. Still extremely expensive. Consider hiding the entire party in a rope trick for the price of a single 2nd-level spell slot – it doesn’t require concentration!
• Blindsight. Get advantage on attacks in someone’s fog cloud, see invisible enemies and make people in heavily obscured areas have disadvantage against you. Still doesn’t make the huge giant crab’s DPR remarkable, but it’s funny on the whale.
• Swimming Speed. If you’re in one of those mythical aquatic campaigns that apparently exist, you should have been prepared for situations that require it a few levels ago. If you’re not in one of those games, this will likely turn out to be useful exactly once.
• Climbing Speed. Amusing, but spider climb is a 2nd-level spell and you’re probably not going to need a regular, spooderless climbing speed in combat.

This isn’t a bad toolkit by any means, but as a conjure animals enjoyer I’m not so easily impressed.

Speaking of which, don’t tell all the polymorph stans who think the player doesn’t get to choose the creatures summoned by conjure animals that, by the same logic, you don’t even get to choose the target of your own polymorph spell, never mind the creature you get turned into.

What fights does it actually help you win?

Polymorph excels in the very niche category of encounters where the following is true:

• You’re around level 7(the spell falls off at higher levels, since your enemies get stronger and the form you turn your friends into doesn’t)
• The encounter is challenging enough to warrant the expenditure of one of your highest-level spell slots, but not hard enough that you needed to cast a concentration spell
• One of your allies, whose contribution to the combat is in some way highly significant, is about to go down and that puts your chances of victory at risk
• Being transformed into a beast does not negate the very advantages that make the endangered ally crucial to winning the fight
• There is enough room for a Huge creature to appear on the battlefield – so your ally is not surrounded and you’re not fighting in a 10-foot hallway(one of the most advantageous locations to fight in, and a common sight in dungeons)

The part where I play devil’s advocate

Polymorph’s value is inversely proportional to the skill of your party. In a completely random party, you’re likely to have some poor longsword fighter who would unironically gain +17 DPR from being turned into a giant ape. If you’re a lone wizard or sorcerer babysitting a group of such martials, chances are that your allies don’t have the tactical skill required to make the most of stronger spells like plant growth, sleet storm or hypnotic pattern.

Polymorph has a relatively high skill floor and the vast majority of online debate does not go past that level.

Should I take this spell?

You’re a fullcaster, you just leveled up and you’re reading this article. Now you’re wondering if that giant monkey/dino spell is worth picking up.

• Bard: It’s not a bad pick since your 4th-level spell options are extremely limited.
• Cleric(Trickery Domain): You get it for free.
• Druid: You can prepare new spells each day, so it’s a lot less of an issue. That said, you get conjure woodland beings which can summon pixies and conjure animals is flat-out better for damage and utility.
• Sorcerer: You have very limited spell picks and as such can hardly afford a “jack of all trades, master of none” option – every tool in your toolkit needs to be specialized. As for Twinned spell, take a look at what I’ve written previously and consider how likely it is that all those conditions are met and two characters of such high significance are about to get downed.
• Warlock: Do not pick the Sculptor of Flesh invocation.
• Wizard: I would not pick it up as one of my two free additions to my spellbook upon gaining a level, but I would strongly consider copying it down if I found a scroll or spellbook as loot.

Other Uses

Besides turning an ally into a pile of meat with a melee attack, you can use it as a single-target shutdown spell. If an enemy fails its Wisdom saving throw, you can turn it into some kind of big aquatic creature like a shark – something with too many hit points for its allies to easily bonk it to 0 HP and revert it to its true form, but also a creature that is immobile and cannot breathe on land for long. Bear in mind that this involves using a 4th-level spell slot to get a ~60% chance of crippling a single monster, takes up your concentration and does nothing if the target succeeds. This will absolutely require you or an ally keeping a reaction and 1st-level spell slot free for silvery barbs to be worth the cost.

You can also turn allies into venomous creatures and milk them using the venom harvesting rules in the DMG. Beasts with poison include gems such as:

• Giant coral snake(CR 4): DC 12 Constitution save, on a failure the target is stunned for 1 round and gets a short-term madness for 10 minutes.
• Giant scorpion(CR 3): DC 13 Constitution save, 4d10 poison damage on a failure or half damage on a success.

So even in an optimized party where your martials(if any even exist) are outdamaging big not-so-scary monkeys and people who desperately need saving from a lethal situation get cheap, concentration-free help like vortex warp or dimension door, there is a reason to consider the spell.

Concluding thoughts

I have massively overrated this spell in the past. While a solid spell, polymorph is nowhere near as strong as I thought, and today I would give it a 3/6 rating(maybe bordering on 4/6).

The spell’s value surges drastically in an unoptimized party, due to the damage gap between a weak martial and a giant ape being quite significant.

It’s up to you to know your party and determine whether it’s worth picking up. Whenever you cast a high-level spell, you should expect it to do a large chunk of the work required to win an encounter. Hypnotic pattern can remove ~60% of the monsters in a 30-foot cube from the encounter for a minute, and you know how good Divide and Conquer is as a strategy.

Know what your slot is worth, for there are many blatant scams printed on the pages of the books, including but not limited to hex, spiritual weapon, haste, phantasmal killer, swift quiver, flesh to stone and weird.

That’s all I had to say about polymorph. Thanks for reading, and until next time!