Spell Spotlight: Contagion

“Ah! Let go of me!”

The halfling cleric shouted in pain and frustration as the necromancer’s gaunt, talon-like fingers tightened around her wrist. She struggled against his grip as he left her aloft, tears of rage welling up in her eyes as her blood began to dribble out from beneath his fetid fingernails. He smiled a wicked, gap-toothed smile as a sickly green glow began to surround his hand, casting his face in long, eerie shadows. The cleric’s face grew pale. Not from fear, though she was nearly paralyzed with it, but with a queasy, vomitous ache in the pit of her stomach.

Her senses began to stretch. The world went into soft focus, and sounds became muffled and quiet. She vaguely comprehended movement to her left, then a flash of steel in front of her. The necromancer’s bony face twisted into fear, and then into pain. A gout of hazy red shot up in front of her face, and she fell suddenly to the ground. The shock snapped everything suddenly back into focus.

“She said ‘let go,’ monster,” the fighter said. She flicked the necromancer’s blood from one of her scimitars and spat upon his corpse. The cleric caught her casting a tentative glance up at the undead horde her allies her fighting, then, assured that she was safe for a moment, turned towards the cleric and knelt down, putting a callused hand upon her chest. “Hey,” the fighter said, “Are you okay?”

The cleric gagged as another wave of queasiness traveled up her guts and into her throat. “Y-yeah,” she stammered, fumbling for the holy symbol around her neck. “I don’t know what’s happening,” she gasped, struggle to hold back her morning rations.

“Your wrist,” the fighter muttered, worry spreading across her face. “It won’t stop bleeding. Oh, gods. Your blood, it’s so thick. It’s like jelly!”

The cleric struggled to focus her hazy vision on her bleeding wrist as the fighter desperately searched for a cloth to staunch the bleeding. The halfling wracked her brain, thinking of what spell could possibly have caused something like this. Then it struck her.

“It’s a disease,” she muttered. “Slimy Doom.”

The fighter looked at her companion and stifled a giggle. “Come again?”

“It’s a magical contagion. It hasn’t taken root yet, though. There’s still time to… Ah!” The cleric muttered a quick prayer and pressed her glowing holy symbol to her wound, casting a lesser restorative charm to purge the magical poison from her body. She looked up at the fighter, warmth returning to her cheeks. “Good as new. Lathander keeps us safe from all ills, does he not?”

The fighter laughed and held the halfling close for a brief, joyous moment, then set her down. “Grab your mace,” she said, glancing at the necromancer’s plague-ridden undead creations. “This isn’t over yet.”


Contagion used to be one of D&D’s most polarized spells. A lengthy online debate raged around this spell since the release of the Player’s Handbook in summer 2014. The reason was that its rules, while interesting, weren’t clear. There were two valid readings of the spell’s text: one that made the spell wickedly powerful, and one that made it practically useless. A recent errata made a small but elegant and impactful change to the spell, transforming it from a spell that sparked furor across the internet to one that now fills a comfortable niche in any cleric or druid’s spell list.

The Woes of Old Contagion

Contagion is a 5th-level spell typically cast by clerics and druids. In short, it infects a single target with a magical disease that will really ruin your target’s week. When you cast the spell, you were presented with six diseases to choose from, corresponding to each of the six ability scores. It seems simple on paper, but there’s a wrinkle: the spell didn’t properly explain how it worked. Here’s the controversial part of the spell’s original text:

“Your touch inflicts disease. Make a melee spell attack against a creature within your reach. On a hit, you afflict the creature with a disease of your choice from any of the ones described below.

At the end of each of the target's turns, it must make a Constitution saving throw. After failing three of these saving throws, the disease's effects last for the duration, and the creature stops making these saves. After succeeding on three of these saving throws, the creature recovers from the disease, and the spell ends.”

It seems fairly innocuous, but there’s a big problem there. It doesn’t specify when the disease takes effect. One way to read it suggests that the spell instantly causes the target to suffer the effects of the disease, and it must make three successful Constitution saving throws to shake it off before it accumulates three failed saves, otherwise it is stuck with the disease for seven full days. When interpreted this way, contagion is a really potent spell, especially when paired with the Slimy Doom disease, which gives the target disadvantage on Constitution saving throws, making it harder for afflicted creatures to resist the encroaching disease.

The other reading of this spell, however, is less impressive. If one assumes that the disease doesn’t instantly take effect when the spell is cast, then contagion ultimately asks you to spend a 5th-level spell slot to do nothing for at least 3 rounds. Then, if the target fails three saving throws before making three successful ones, the disease takes effect for seven days. But, by that point, the battle is probably already over.

The real issue here is that if you interpret contagion charitably, its effects were ridiculously overpowered. If you appraised contagion less highly, the spell was essentially useless in combat. Most fights would be finished by the time the disease took root, and that’s assuming the target failed its saves at all! Its most effective use under this reading was as a slow-paced, out-of-combat spell, used for secretly infecting NPCs with a disease that would slowly ravage their bodies.

Fortunately, this all changed.

The New, Shiny Contagion

Contagion got some special attention in a recent update to the rules released in November 2018. It’s not distinctly a buff or a nerf, since it makes one reading of the old rules better and one reading worse. What it does quite successfully, however, is clear up any confusion on how this spell works. Now, when the spell is cast, the target creature is poisoned. While poisoned in this way, the creature must make a Constitution saving throw at the end of each of its turns. If it gets three successes before three failures, it resists the disease and the poisoned condition ends. If it gets three failures first, however, the disease kicks in.

This errata solves contagion’s biggest problems by sucking out any ambiguity in the original rules. The “weaker” version of contagion in the old rules has been highlighted as the proper reading of the spell, and that version has been given a tidy buff in the process. But then, if you were playing with the more powerful version of contagion before, you might feel like your favorite spell was just knocked down a few pegs. Ultimately I think it’s for the best; contagion still has a clear niche that few other spells occupy, and now it won’t cause nearly as many arguments at the table.

But it’s not perfect.

Contagion’s Awkward Shortcomings

Contagion has always had a pretty serious weakness. Namely, it’s easy to cure diseases in D&D, especially by the time contagion, a 5th-level spell, is being used against you. A simple casting of lesser restoration is enough to scrub the sickness away. Trading a 2nd-level spell slot for a 5th-level one is a great trade for the heroes, but it’s a pretty raw deal for the villainous necromancer who cast it in the first place. And it’s not hard to become immune to disease, either. Paladin’s gain that power at 3rd level through their Divine Health feature, and the periapt of health grants disease immunity for only the cost of an uncommon magic item.

As a point in contagion’s favor, however, most characters won’t be ravenously hunting for a periapt of health, since diseases are generally not a major problem in D&D. Poisons are dangerous, traps are deadly, and monsters are an omnipresent challenge, but diseases don’t turn up too often. Overcoming a disease (typically) isn’t the stuff of heroic fantasy in the same way that monsters and poisoned daggers are.  So many characters will be caught off-guard if this spell is used against them, and precious few Dungeon Masters will remember to give their important villains a periapt of health, just in case.

The new version of contagion, however, makes things a bit more difficult by introducing the poisoned condition into the mix. First of all, curing poison is no harder than curing disease; a simple lesser restoration will still do it. And if you can get rid of the poisoned condition, the afflicted creature doesn’t have to keep making saving throws against the encroaching disease, and the spell ends. So far, nothing has really changed.

The big problem is immunity to poison. By introducing the poisoned condition into its process, contagion has suddenly become a lot less useful for player characters, while remaining similarly effective for Dungeon Masters. While most player characters aren’t immune to poison (who’s buying a periapt of proof against poison, anyway?), a lot of monsters are. Undead, fiends, celestials, elementals, constructs—practically all creatures who fall under these categories are immune to the poisoned condition, along with a handful of aberrations and monstrosities, and a smattering of other random creatures.

Now, even though these creatures aren’t immune to diseases, their immunity to poison prevents contagion from ever taking root. Generally speaking, it makes sense that you can’t infect fiends, celestials, elementals, undead, or constructs with a disease anyway, so even though they could be infected by rules-as-written (RAW), a DM should be fully empowered to rule that they’re immune. But some of the edge case creatures, like the hardy dire troll is immune to being poisoned simply by virtue of its mutations and its strong stomach. A disease that causes blindness or that enflames the mind shouldn’t be edged out by this paltry immunity. The same goes for green dragons, who are immune to being poisoned by virtue of their poisonous breath. Surely that shouldn’t grant it immunity to disease.

This is a rules quirk that may stymie players who take RAW as gospel. I’ve seen many such players in the D&D Adventurers League. Ultimately, however, it is the role of the DM is to adjudicate the rules in a coherent manner. If a creature is immune to being poisoned because it lacks blood or living flesh, then it makes sense that it’s also immune to diseases and thus, the contagion spell. If it is immune to poison because it employs venom or poisonous gas in its attacks, then it should be affected by contagion’s “poisoned” effects as usual.

Even if you’re DMing an adventure in the D&D Adventurers League and feel bound to follow RAW, recall the first major piece of advice: You’re Empowered. You can bend the rules to suit the story, and to make the world make a bit more realistic. Don’t break the rules into tiny pieces, but don’t feel constricted by them, especially when they don’t make sense.

Have you used contagion in your D&D game? How do you like the update to this spell in the latest errata? Let us know in the comments!

James Haeck is the lead writer for D&D Beyond, the co-author of  Waterdeep: Dragon Heist and the Critical Role Tal'Dorei Campaign Setting, the DM of  Worlds Apartand a freelance writer for Wizards of the Coast, the D&D Adventurers League, and Kobold Press. He lives in Seattle, Washington with his partner Hannah and their sweet kitties Mei and Marzipan. You can usually find him wasting time on Twitter at @jamesjhaeck.


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