For a 1st level character, there are few things more important than avoiding damage. When you have an initial set of hit points that can be wiped out with a few good hits, protecting them jealously becomes a critical survival skill.
And while casters have a few options for defensive spells to keep their stash of hit points intact, there is one 1st level spell that stands out. So, let’s look at a spell that any Warlock should consider to keep their hit points intact – D&D 5E’s Armor of Agathys.
What is Armor of Agathys?
Casting Time: 1 action
Components: V, S, M (a cup of water)
Duration: 1 hour
When cast, the spell causes a spectral frost to cover the caster and their gear. This frost acts as a protective layer granting 5 temporary hit points.
Additionally, any creature that hits the caster with a melee attack while any temporary hit points remain will take 5 hit points of cold damage. If the spell is cast with a higher-level spell slot, both the temporary hit points and the cold damage increase by 5 for each level above 1st.
Armor of Agathys is found only on the spell list for Warlocks. However, it is accessible to Bards via the Magical Secrets ability, and Paladins taking the Oath of Conquest receive it as an oath spell at 3rd level.
The Good and the Bad
A first level spell that not only grants temporary hit points but also does damage to melee attackers? There’s not a lot of downsides to that, but let’s nitpick it a bit.
Cold damage is the most common resistance in the game, so that 5 hit points is less likely to land than it would be if it were, say, lightning damage. Still, if you’re not facing arctic creatures or undead, the odds are still in your favor.
Five temporary hit points may not sound like much but look at that closer. At 1st level, a Warlock will have their max 8 hit points with a what, maybe +2 CON bonus if we’re being generous? That means Armor of Agathys is giving you a 50% hit point bonus, and that’s not shabby at all.
These extra hit points work equally well for a Bard. And while the impact would be less for a Paladin, it’s still not insignificant.
And the spell scales well, adding another 5 points on both sides for each level of spell slot above 1st. When a Warlock reaches 3rd level, they can cast Armor of Agathys with a 2nd level slot and get 10 temporary hit points (and do 10 cold damage).
Even if you max out HP through 3rd level (you won’t, unless your DM is suspiciously generous), that’s still a hefty bonus to carry around for up to an hour. That makes outgrowing this particular spell a slower process than for some other low-level spells that lose their luster.
Perhaps two of the best things about Armor of Agathys is that it has an hour-long duration and isn’t a concentration spell.
That means you don’t have to wait for a fight to start before you pull the pin on it but can cast it when you know a fight is likely in the next hour or so. And anyone who’s entered an old castle or ruin before can usually have at least a vague idea about such things.
And since the spell takes no actions to maintain and doesn’t require concentration, the caster is completely free to throw any spells in their quiver without interfering with the protection this spell is giving them.
Scrounging around for more downsides, we can note that the spell doesn’t deal damage to those attacking with missiles, though that’s not such a big deal.
More significantly, a grapple isn’t technically a melee “hit”, so it’s arguable whether the spell’s damage would kick in for that (though it seems like a logical ruling for a DM to make).
But back on the upside, the spell’s description notes that the frost covers the caster and their gear, which could have some interesting possibilities, notably regarding pickpockets and the like).
But when weighing the pros and cons of Armor of Agathys, we must look at other spells you could take in its place. While nothing does quite what this spell does, there are a few others that do offer defensive benefits of one kind or another and deserve a look.
While this spell doesn’t appear on the Warlock list, it is an option for Bards and Paladins. More to the point, it can be cast on any willing target, so the Warlock could still benefit from it with a helpful ally.
Heroism is another 1st level spell and grants temporary hit points equal to the caster’s spellcasting bonus. That should put it in line with the 5 temporary hit points from Armor of Agathys, on average.
Unlike Armor of Agathys, however, Heroism doesn’t add additional increments of hit points when cast with a higher spell slot. Instead, higher spell slots simply let you target more creatures, and while that’s nice, the small HP boost is going to become less valuable as character levels rise.
The other downside is that the spell lasts for only a minute and requires concentration on the part of the caster. Heroism isn’t suitable for casting “just in case” there’s a fight, but the duration will get you through most melees once the fight starts. And Heroism grants temporary hit points each turn, not just once, giving a replenishing buffer of hit points while the battle is going on.
This 1st level spell on the Sorcerer and Wizard lists boosts the target’s natural AC to 13 + their Dexterity bonus. Unlike Armor of Agathys and Heroism, it doesn’t confer temporary hit points, nor does Mage Armor stack with actual armor as the other two spells can.
With an 8-hour duration, a single casting of Mage Armor could effectively last through an entire day’s adventuring portion. On the downside, the spell doesn’t scale with higher level spell slots, so it’s use is largely limited to the lowest level characters.
Is Armor of Agathys Spell Worth It?
The temporary hit point bonus and cold damage dealt by Armor of Agathys make it an above average spell for a 1st level caster. And its ability to stack with regular armor or a spell like Mage Armor make it even handier.
Unlike other low-level defensive spells, Armor of Agathys scales well enough to remain useful as the caster levels up. And while it’s best geared to melee-oriented builds like Pact of the Blade Warlocks or the Oath of Conquest Paladins, it works for any character wanting a bit more of a defensive edge when combat starts.
Can you stack Mage Armor and Armor of Agathys?
Yes, you can. The two spells create different magical effects, with Mage Armor raising natural AC and Armor of Agathys granting temporary hit points, so they do not conflict with each other.
How much damage does Armor of Agathys do?
Any creature making a melee attack against a target protected by Armor of Agathys (i.e., still has at least 1 temporary hit point) takes 5 cold damage. When the spell is cast with a 2nd level or higher spell slot, this damage is increased by 5 for each level above 1st.
Is Armor of Agathys a bonus action?
No, casting Armor of Agathys is a standard action.