D&D 5E Setting Party level vs an Ancient Red Dragon

Reynard · Dec 9, 2017

I am hoping to get a little insight into setting up a one shot adventure. The characters all exist, but they have been "off screen" for a while so they can be any level. There are going to be 10 of them. So, what level do you think will be right for a fight, in lair, versus an Ancient Red Dragon (CR 24 per the MM)?

A couple notes: I run large groups relatively regularly and I have noticed that big groups inherently punch above their weight class. Throw in the fact that they are likely to be able to be fresh upon entrance to the lair, I am thinking that the party does not have to be especially high level. The thing has an astoundingly low AC and its saves are not magnificent either. Now, it can dish out a lot of damage and can probably kill a non-barbarian PC per round almost regardless of level, but even with 500+ hit points I don't see it lasting long enough to kill all 10 characters.

What level would you make the PCs in order to make this an entertaining, difficult and tense encounter with a decent chance of killing more than a couple of them, but a relatively low chance of a TPK?

Thanks.

Sunseeker · Dec 9, 2017

8th, tops. They're going to kick it's butt with the sheer number of turns they have in comparison. If 10 people deal an average of 10 damage per turn, it'll dead in 5 rounds, the dragon will barely get off the ground. If they're fresh at the start of the fight, they'll likely go nova, and it wouldn't surprise me if they drop the dragon in 3 rounds.

hawkeyefan · Dec 9, 2017

I would double the number of Legendary Actions and uses of Legendary Resistance against such a large group. If you want the fight to be a long one, then I’d also significantly bump the dragon’s HP.

As for the level of the PCs, with 10 of them, I’d say around level 10 or so, depending on how you guys build your PCs. It will also depend on how you play the dragon, and if it is indeed alone (which is how it seems) or if there will be other monsters involved.

Stalker0 · Dec 9, 2017

10th level was in my head as well. 10 actions a round is a lot of hootspha. Especially if they have time to plan.

Storyteller Hero · Dec 9, 2017

shidaku said:
They're going to kick it's butt with the sheer number of turns they have in comparison.

Here's the thing. A dragon is only as weak or as strong as the circumstances under which it is fought allow it to be and how the DM plays it. If played to its full potential, a dragon is far more deadly than many people might realize.

For example, if the dragon is already in flight when the battle begins, then it can swoop down and pick up PCs with a grapple to toss or drop them with great force, or use its breath weapon from a distance.

For example, if the dragon is being attacked in its lair, then there are any number of traps and lair actions that could greatly hinder the PCs from even reaching the monster.

For example, if the environment is destructible or mutable then the PCs have to worry about things like falling debris, or burning trees, or cracks in the ground, or difficult terrain.

For example, if the dragon is attacking in an area with lots of obstacles, then it can potentially use cover against the PCs.

Grappling, flight, environmental obstacles, hazards, the improvised damage table in chapter 8 of the DMG, lair actions, traps, and falling damage - it is easy for a DM to overlook any one of these aspects of the game, thereby making a dragon fight easier than it would be if playing an intelligent dragon as it might logically behave under reasonable conditions.

hawkeyefan · Dec 9, 2017

[MENTION=6813635]Storyteller Hero[/MENTION] Great post. Everything you mention can’t be said enough.

Tormyr · Dec 10, 2017

The problem with an 8th-level party is that the breath weapon is enormous (DC 24 DEX save, 90-foot cone, 91 [26d6] fire damage) and can wipe out lots of them in one blast. Its Frightful Presence splits the party, and it can grab a week PC, fly away with it and finish it off, return for another one with a recharged breath weapon, etc.

I generally scale the monsters when there are more than 4 PCs in the party. An ancient red dragon is about the XP per day for 4 level 14 PCs. This would be a difficult but winnable fight with maybe 1 or 2 dying / going unconscious. I would then boost it by 90 hit points for each PC above 4. Each unit of 90 hp can be used for an additional legendary resistance if needed. There will be a lot more spellcasters using save or suck spells.

So the ancient red dragon would have 1086 hp, and you can take 90 hp off if the dragon is being barraged by save or suck spells, attempts by a monk to stun, etc. My guess is the dragon survives about 3-4 rounds with a couple PCs going down in the first round or 2 depending on their starting hit points and how the breath weapon went.

Make sure everyone knows what they are going to do before their turn comes up as they play characters with completely new powers. With 10 players, the enemy is going to be slow play rather than the dragon.

Eltab · Dec 10, 2017

My Rise of Tiamat group faced Arauthator in his lair at whatever level the book says the PCs should be (L12?). We had about 6 adventurers that night.
I planned ahead as DM, plus made him an Ancient White with max HP &c. Arauthator took off on Turn One, flew towards the PCs, and used Frightful Presence over the middle of the group, scattering them. Legendary Actions followed the toughest PCs' turns. I had the advantage for three rounds, and forced half the group to 0 HP (making Death Saves).

Then I made the mistake of hovering just within reach of one PC.

The group revived themselves and had the advantage for the next three rounds; they ultimately slew Arauthator with no casualties.

Lesson learned 1: have an attack plan that uses the dragon's abilities.
Lesson learned 2: stick to that plan; keep attacking the PCs until they are all dead or you run out of HP.

Stalker0 · Dec 10, 2017

Tormyr said:
The problem with an 8th-level party is that the breath weapon is enormous (DC 24 DEX save, 90-foot cone, 91 [26d6] fire damage) and can wipe out lots of them in one blast. Its Frightful Presence splits the party, and it can grab a week PC, fly away with it and finish it off, return for another one with a recharged breath weapon, etc.

I generally scale the monsters when there are more than 4 PCs in the party. An ancient red dragon is about the XP per day for 4 level 14 PCs. This would be a difficult but winnable fight with maybe 1 or 2 dying / going unconscious. I would then boost it by 90 hit points for each PC above 4. Each unit of 90 hp can be used for an additional legendary resistance if needed. There will be a lot more spellcasters using save or suck spells.

So the ancient red dragon would have 1086 hp, and you can take 90 hp off if the dragon is being barraged by save or suck spells, attempts by a monk to stun, etc. My guess is the dragon survives about 3-4 rounds with a couple PCs going down in the first round or 2 depending on their starting hit points and how the breath weapon went.

Make sure everyone knows what they are going to do before their turn comes up as they play characters with completely new powers. With 10 players, the enemy is going to be slow play rather than the dragon.

just remember that as long as a player has 46 hp (which is very reasonable for an 8th level character), they will survive an opening 91 hp breath weapon.

So they are one healing word away from back in the fight.

I actually do agree that the frightening prescience maybe the strongest weapon in the dragon aresenal at that point. 8-10th level parties don’t have the fear resistance of high level groups

Tormyr · Dec 10, 2017

Stalker0 said:
just remember that as long as a player has 46 hp (which is very reasonable for an 8th level character), they will survive an opening 91 hp breath weapon.

So they are one healing word away from back in the fight.

I actually do agree that the frightening prescience maybe the strongest weapon in the dragon aresenal at that point. 8-10th level parties don’t have the fear resistance of high level groups

Sure, they are not dead yet, but a 90-foot cone is massive. Half the party could be down in the first shot. 1 or 2 might get back up, but it is a 1-in-3 chance that the dragon does it again. Then they are dead from massive damage. Otherwise, the dragon uses frightful presence, knocks the ones with healing word back down again, and focuses on the next weak target.

I just think any party that goes in without most of their members having at least 92 hp (whether actual hp, resistance, or other effects) is heading toward pain. That is why I usually scale the monsters HP when there are more PCs. It increases the monster's chances of survival to at least 3 rounds and avoids the chance of a TPK within the first couple rounds from massive damage.