Broken?

I mean only Slimy Doom is really 100% broken, the other diseases while detrimental are a little more tolerable, though apparently there was some announcement that the disease doesn't have ANY effect until they fail 3 saves, which would make this spell really useless for a 5th level spell if it just did nothing for 3-5 turns and then MAYBE had an effect...

What the heck?! Why did you make this spell useless? At fifth level, this spell will NEVER get used by anyone trying to figure out their spell lists. Thanks for nothing.

So I'm not sure I fully understand this spell. First off, you get access to this at level 9 or higher. Right at level 9, this spell seems possibly useful as a long term debuff but there's some start up time before you get any benefit, and it can always fail like all attacks and spells can fail. At level 9 your likely to have 20 in your casting stat so you attack with this at +9 to your roll, and your dc is going to be Con 17 to beat. Given that scenario, it's not impossible to think that a team of 4-6 adventurers would be facing off against something like a Beholder or maybe something super ugly like an Elder Brain. These 2 options are obviously ideal considering that the enemies have lower Con saves and potentially enough health and enough resources to prove a long term problem for the party. Being able to blind a Beholder and deny its eye rays is a huge boon for the team, Stunning or Confusing an Elder Brain is comparatively very strong also, denying the enemy turns to act and denying the enemy resources in a long term fight.

That being said, it's a very niche spell I imagine. Considering that likely in the later stages of an adventure, you're going to face off against extra planar enemies or ancient horrors, something to keep in mind is that if an enemy is Immune to the Poisoned condition then I imagine they are immune to this spell completely. Meaning this is effectively useless on most Undead, Constructs, Fiends, Elementals, Celestials and a number of other enemies.

Something that also is to consider, this may be possibly useful for baiting out Legendary Resistances. If you are fortunate to land 2 failed Con Saves, it's unlikely that a Legendary creature would allow themselves to fail a 3rd time if they could prevent it. Meaning this spell would be a guaranteed failure if the enemy has 3 legendary saves and uses all 3 to save against this spell, but having the enemy expend their resources on a 5th level spell might be better than having them resist higher level spells you cast later in your conflict.

Agreed, it's completely broken. This spell is useless and will never be used by a single caster, ever, anywhere, in any game of D&D.  It is complete trash, especially for a 5th level slot, especially considering the creatures you'll fight by time you can cast this are generally far more powerful and able to withstand silly conditions like poison or disease.

Creatures immune to poison? Immune to this spell
Creatures Immune to disease? Immune to this spell

Poison immunity being by far the most common immunity out of them all (over 100 creatures with immunity to poison). Disease being high on the list as well.

One way is to make Contagion, actually...contagious?...

Have it jump a creature in a 10feet if it every 2 turns, to a max total of 4 creatures, is the spell is cast at higher lvls, for each lvl, add 2 Max creatures that can be infected.

Completely wasted spell concept. While yes this was viewed as powerful or worthless there were still many creatures that would just ignore this and now this spell is even more useless since it was changed to be a poison spell. There are far more creatures(common creatures I might add) that do not care about poison. So many things, especially cheap things can cure or negate a poison. This is just about as bad as making so many things require concentration especially when a chunk of those spells do not have an upcast bonus. My favorite upcast bonus will hands down always be Bestow Curse, for a fairly high level spell slot you no longer need to have concentration! Why can that not be a thing for other spells?

Seems to me, if you think a spell is too weak or too powerful: if you're a DM: just change it!  If you're the player, make a good faith argument to your DM about how you think the spell should work.  Both players and DMs should be able to make changes to the rules that they believe make their game better.

  Personally, I think a handy addition would be: "Any creature that starts and ends its turn within 5 ft of an infected creature, is treated as if they were hit by Contagion."  Of course, they you'll get your Barbarian volunteering to be hit by it, and then run into the enemy stronghold!

Take a slave/friend/creature into the middle of town and give them a hug, then when they fail, have them spit in the well. 

Wow, this seems... fun. And also completely broken with the power of slimy doom.

I would say it's still usable as an assassin spell. If it's a touch, just pushing your target in the street should work, tough I may be wrong

Seems like a fantastic anti-dragon spell, Burn down those legendary resistances of course....

I trust the caster picks the effect?  Each time you damage the dragon it's stunned?  Lol, game over....

Again a creature that Iis immune to poison, I would  say that the magic would linger and the saving throws would still happen. It is not a CON (vs Poison) but just a CON save. After three turns the magic happens or not.

Unfortunately it says the saves happen at the end of the poisoned targets turn. If the target isn't poisoned it doesn't make saves.

Contagion haters, you have no imagination. Not every spell listed in the PHB is designed to be used by noble adventurers. A handful of spells, and seldom few like this one especially, are designed to be used by villainous characters and antagonist NPCs. You could maybe use it effectively against a number of creatures in combat, sure, but it clearly is suited best to be used against humanoids with a good plan in place.

Take a look at the classes that can cast it. It's available to the OATHBREAKER and the UNDYING paladin and warlock. Those aren't typically the nicest guys at the block party.

This spell is great. With luck (or better yet, smart planning) this spell could prove very versatile and powerful, so quit complaining about it. It's always available if you want it, but no one says you have to prepare it. A lot of the uses for this spell are best made with plans. Try this for example... This is a TOUCH spell. That means if you have a familiar (take the magic initiate Feat to get it), you can send your tiny evil emissary to do the deed from a distance.

Bed rid a political adversary! Offer to heal their illness as pretext to get past their guards so you can kill them?
Rig a gladiator match or duel, by INVISIBLY forcing a severe detriment onto them.
This spell is a tool for clever characters who have big spell slots, but aren't sure what they want to do with them yet. This one spell has several uses.

The spell shouldn't require you to multiclass or get a specific feat in order to use it effectively, especially since it is a circle or patron spell. As written there isn't a way to stealthily deliver this spell outside of an undying warlock with the pact of the chain. Outside of stealthily delivering the spell, you are basically only left with delivering it in combat or just before combat, which means that at best you won't get any benefit from it until 3 rounds after you cast it, but it probably won't take effect until 4 or 5 rounds if it takes effect at all because it requires both an attack roll and a common save. Also, since it's a natural disease it can be cured by as little as a lesser restoration, or a good enough medicine check depending on your GM.

There's no need to multiclass or take the magic initiate feat to use this spell effectively. They could just make it easier.

Saying "As written there isn't a way to stealthily deliver this spell outside of an undying warlock with the pact of the chain" is a little disregarding of the versatility and value of stealth. Contagion is a spell that works best when delivered stealthily, yes, but familiars aren't the only way to do it. Disguise kits, illusions, good ol' fashioned lying. This is a spell best used with a plan, and if you can't cast it at a distance, an escape plan is always a good idea. Teleportation, expeditious retreat, landstride, fly, wall of stone, heck... a well trained horse and a spider climb spell... just a horse! Combat only really happens when you stick around and let it happen. There's lots of ways to escape it when you have a plan to do so.

Lesser restoration is a thing, sure, but access to that spell depends a lot on the setting of the campaign and who is being targeted by the spell. Contagion isn't a spell for all scenarios, but it is great for a good number of them. If it won't work, do literally anything else. Just 'cause it's harder to use effectively doesn't mean it shouldn't be valued for what it can do. Magic Jar is similar in that it requires a good plan to use effectively, but with a good plan is a very useful tool.

It's a perfectly valid plan to tap someone with the spell (while disguised or hidden), and then leave as quickly as possible. There are a myriad of ways to do it.

The problem is that they are going to realize that you are casting a spell before you can finish casting it, which leads to initiative being rolled. Even if you do get it off and then escape, they are probably going to be well protected while they are sick. It would be easier to kill them right after you cast it than it would be to sneak your way into their lair twice.

Look, there are interesting ways this spell can be used, but it's just not well designed to be used as a combat maneuver.

Fair enough, I just think the spell could be better. As is it's a very niche spell.