Is this legit?

[Gtdead]

I was trying to find a way to nova with cleric, and I noticed that the contagion spell has an effect called flesh rot, that makes the target vulnerable to all damage.

Assuming a tempest cleric 18/fighter 2, can I just contagion, and then cast a call lightning (maximized), and then use action surge to call another one? This can deal up to 400 dmg in the second turn!

Is this real life or am I missing something? I mean, even if the target saves against everything, it's still 180 dmg minimum using a 9th slot. And you can do one more maximized call down next turn.

[Mellack]

I believe the errata has clarified that the subject does not actually get any penalties of the disease until they have failed the required three saves. If you DM allows immediate effect, then you are good.

[Solusek]

Call Lightning is a concentration spell, so having two going at once may be difficult.

[Gtdead]

Not trying to have 2 concentration spells, but the spell says that I can use an action to call down a lightning from the cloud. Can't I do that with action surge?

Also the errata doesn't mention contagion but it is mentioned in sage advice.. hadn't noticed..

[EvanescentHero]

Call Lightning is a concentration spell, so having two going at once may be difficult.

On top of this, you can't cast two spells in one turn unless one of them is a cantrip, I believe.

EDIT: Hmm, with the above information, I suppose technically that could work, but as a DM I would likely not allow that.

[Hikarizu]

On top of this, you can't cast two spells in one turn unless one of them is a cantrip, I believe.
If you cast a spell with a bonus action the spell you used for your action have to be a cantrip. If you use another action like the one granted by action surge there are no such limiters.

[EvanescentHero]

If you cast a spell with a bonus action the spell you used for your action have to be a cantrip. If you use another action like the one granted by action surge there are no such limiters.

Ugh. Thanks for the clarification, but this is more complex than it needs to be, and more than I'd like for this edition.

[Desamir]

Not trying to have 2 concentration spells, but the spell says that I can use an action to call down a lightning from the cloud. Can't I do that with action surge?

Also the errata doesn't mention contagion but it is mentioned in sage advice.. hadn't noticed..

It's possibly the worst-written spell in the PHB. I'm surprised that Jeremy Crawford didn't think it was errata-worthy.

[SharkForce]

you're not casting 2 spells. call lightning takes an action to cast and lets you immediately use a lightning bolt on something, then it also gives you a new action you can take that is not the "cast a spell" action, to call down lightning again. since you are not in fact casting a spell after the first action for call lightning, you can even use a bonus action spell and activate call lightning in the same round, or you could quicken call lightning and then use your regular action to call down another lightning bolt.

[Lines]

I believe the errata has clarified that the subject does not actually get any penalties of the disease until they have failed the required three saves. If you DM allows immediate effect, then you are good.

It's not in errata. And either way it's a badly written spell - RAW it applies immediately, meaning slimy doom gives disadvantage on its own saves and destroys pretty much anything, while if your DM chooses to go with what some people might call the RAI interpretation (since sage advice says so) the spell becomes absolutely useless.

TL,DR: It's either too good or completely useless.

[Lavok Rammstein]

I believe the errata has clarified that the subject does not actually get any penalties of the disease until they have failed the required three saves. If you DM allows immediate effect, then you are good.

It's not in the official errata, but there is a sage advice about it only taking effect after three failed saves.

[Mellack]

It's not in the official errata, but there is a sage advice about it only taking effect after three failed saves.

You are right, it was sage advice and not errata. I remembered that it was some sort of official word on how it should be run.