D&D 5E Vs Vecna battle simulations.

[Flamestrike]

Vecna can damage himself to heal if needed.

Hahaha. Bit cheesy, but RAW works.

Vecna can counter subtle spells.

No he cant.

He can only target 'a creature he can see that is casting a spell'. If he doesn't know you're casting a spell (subtle spell) he cant counter it, even if he can see you.

 

[Flamestrike]

Which is why the plan is to run the fight at successively lower levels, and see when - or if - it turns in his favour.

4 x 17th level PCs is where it turns in the Players favor for mine.

Could go pear shaped for them though. But it is a deadly fight.

You could pull it off at lower levels, but it's definately in Vecnas favor.

His main weakness is his absurdly low HP. If he lost initiative to all 4 PCs, then the nova strike on him could drop him in round one.

 

[MonsterEnvy]

Hahaha. Bit cheesy, but RAW works.

No he cant.

He can only target 'a creature he can see that is casting a spell'. If he doesn't know you're casting a spell (subtle spell) he cant counter it, even if he can see you.

He just has to see them exactly. Vs Normal Counterspell where you have to see the spell being cast.
How subtle it is does not matter.

Vecna can ascertain the capabilities of spellcasters and identify the spells they cast without making an ability check.

 

[Swarmkeeper]

Ok, I think I misunderstood the example at first. So, were the rogue and the wizard both hidden behind the parapet at the start of their respective turns? If so, I would grant them both advantage on their attack rolls. Afterwards, the rogue could duck back behind the parapet and use a bonus action to try to hide again with Cunning Action, though I don’t think doing so would be the best use of their bonus action given that the enemies would know exactly where the rogue was hiding and could easily move to a position from which they could see the rogue (assuming such a position exists within range of their movement), therefore rendering the rogue no longer hidden from them. The wizard could also duck back behind the parapet on their turn, but lacking any ability to try to hide as a bonus action, and having already used their action to attack, the only benefit they would get from doing so is whatever cover the parapet provides. And, of course, having seen the wizard do so, the enemies could move to a position from which they have a clear view of the wizard on their turns, (provided such a position exists within range of their movement).

Thanks for the responses - definitely given me food for thought although I'm not totally convinced yet (and am predictably frustrated with my ability to make my example clear ).

We can drop this tangent now as it appears at least one more is beginning...

 

[FitzTheRuke]

Of course.

More to the actual point I'm trying to make: What differentiates the rogue crouching down behind the parapet after taking a bow shot from the wizard who is nearby doing the same thing after shooting a fire bolt? Why does the rogue, due to bonus-action "hiding" behind the parapet, get to have a another chance at advantage at their next bow shot but the wizard does not get that same chance at advantage on their next fire bolt?

What? The Wizard CAN do that! It just takes him a hide action! The rogue just does it quicker because... he's a rogue.

EDIT: I see that I'm late to this bit. I had something else I was going to say here, but I've just blanked on it. I'll be back.

 

[Flamestrike]

He just has to see them exactly. Vs Normal Counterspell where you have to see the spell being cast.
How subtle it is does not matter.

https://rpg.stackexchange.com/questions/122014/can-i-counterspell-a-subtle-spell-without-material-components#:~:text=Subtle%20spell%20is%20meant%20to,can't%20see%20the%20casting.

Doesnt matter if he knows I 'can' cast. If he cant see me casting a spell (he doesnt know Im casting a spell) he cant counter it, even if he can see me.

As long as the spell has no material components, he cant counter a Subtle spell. He cant see it being cast.

 

[MonsterEnvy]

https://rpg.stackexchange.com/questions/122014/can-i-counterspell-a-subtle-spell-without-material-components#:~:text=Subtle%20spell%20is%20meant%20to,can't%20see%20the%20casting.

Doesnt matter if he knows I 'can' cast. If he cant see me casting a spell (he doesnt know Im casting a spell) he cant counter it, even if he can see me.

As long as the spell has no material components, he cant counter a Subtle spell. He cant see it being cast.

And it still does not matter he just has to see you and he instantly knows as it was already said. His wording is different than the other counter spells.

 

[Flamestrike]

And it still does not matter he just has to see you and he instantly knows as it was already said.

No he doesnt instantly know you're casting a spell. He can just identify a spell as it's being cast without needing to make an ability check, presuming he knows a spell is being cast.

And as your (M component lacking) spell is being cast Subtly (with no V or S components), he doesn't see you cast it, so he doesnt know you're casting a spell.

All he sees is you literally just standing there looking at him. There is no trigger for his reaction.

 

[DND_Reborn]

Vecna's Turn:

1. Since Vecna cannot use his Flight of the Damned, Rotten Fate, or Spellcasting, he uses his action to attempt to escape the grapple, rolling his Dexterity (Acrobatics) check bonus of +3.
2. Egar uses his last portent die, so Vecna's roll is a 6 + 3 = 9.
3. Hjalman rolls his Strength (Athletics) check, getting a 18 (9+9), so Vecna remains grappled. Since his speed is 0, he cannot stand or move.
4. Vecna cannot use his bonus action for Vile Teleport due to the antimagic field.

It is now Leon's Turn.

 

[Smythe the Bard]

so, just to ask for a ruling... so I understand DS isn't doable in the A.M. fields, however word from the mount says IDS is.... what say you DM?