A protective magical force surrounds you, manifesting as a spectral frost that covers you and your gear. You gain 5 temporary hit points for the duration. If a creature hits you with a melee attack while you have these hit points, the creature takes 5 cold damage.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, both the temporary hit points and the cold damage increase by 5 for each slot above first.

My Comments: The material component is a glass of water. I’m trying to imagine walking around dangerous areas with a cup of water. My favorite part is the lack of description of what it is you’re supposed to do with the cup of water. Hold it carefully to avoid spilling? Splash it in front of you? Drink it? I have so many questions…

Okay, let’s focus on the spell. First off, the flavor is great. I love the idea of getting coated in a protective spectral frost. Nifty.

Now the mechanics. First, let’s look at the rules for temporary hit points:

Temporary Hit Points

Some spells and special abilities confer temporary hit points to a creature. Temporary hit points aren’t actual hit points; they are a buffer against damage, a pool of hit points that protect you from injury.

When you have temporary hit points and take damage, the temporary hit points are lost first, and any leftover damage carries over to your normal hit points. For example, if you have 5 temporary hit points and take 7 damage, you lose the temporary hit points and then take 2 damage.

Because temporary hit points are separate from your actual hit points, they can exceed your hit point maximum. A character can, therefore, be at full hit points and receive temporary hit points.

Healing can’t restore temporary hit points, and they can’t be added together. If you have temporary hit points and receive more of them, you decide whether to keep the ones you have or to gain the new ones. For example, if a spell grants you 12 temporary hit points when you already have 10, you can have 12 or 10, not 22.

If you have 0 hit points, receiving temporary hit points doesn’t restore you to consciousness or stabilize you. They can still absorb damage directed at you while you’re in that state, but only true healing can save you.
Unless a feature that grants you temporary hit points has a duration, they last until they’re depleted or you finish a long rest.

Okay, so it’s important that they don’t stack, you have to choose one or the other when given two sources of temporary HP. This is important because it means you can’t “hide” your 5 THP (temporary hit points) from this spell under a second set of THP from another spell or affect.

This means that if you gain THP from another source and you take them, your Armor of Agathys ends because you no longer have “these hit points” as described in the spell. It doesn’t matter how you lose them, if you don’t have them, the damaging aspect of the spell ends.

Next up, you deal cold damage to your opponent when they hit you. Cool, literally.

Some things to consider-

• Here’s a fun thing- grappling isn’t hitting and won’t trigger Armor of Agathys. Watch out for those brawlers!
• Oddly, having a high AC may not be helpful when using this spell, given that you need to be hit for it to trigger.
• It’s 5 damage no matter how much damage you took. Get hit for 10 damage? You do 5 back. Get hit for 1 damage? You still do 5 back (per spell level slot, see below)
• Also, it’s full damage damage back, even if you only have 1 THP left.
• It escalates nicely. Basically, it’s 5 THP and damage per level of spell slot. 5 & 5 as a first level spell, 10 & 10 as a second level spell, and so on.
• This seems like it’s really best for Pact of the Blade Warlock, given they are more likely to be involved in melee fighting.
• However! Armor of Agathys is also an option for Oath of Conquest Paladins, which is a pretty awesome combination.
• And finally, it lasts an hour without being concentration, so you stay nice and frosty the whole time.

All in all, it’s a pretty great spell for first level if you can get use out of it. Knowing my luck, I’d spend the whole hour being attacked by Kobolds with bows.

If I were building a Pact of the Blade melee combat warlock (Bladelock) or and Oath of Conquest Paladin, I would definitely use this spell.

[pssst… want to draw a card from The Deck of Many Things?]

[P.S. Check out the Wacky Dungeon game just above the footer!]