D&D 5E Everybody’s Monster Fighting

[rgoodbb]

If I want to have my 4-5 players be CR 6-7 monsters for a 1-shot (an Oni, a Shadow Dancer etc.), what CR rating/budget would the actual monsters be? What creatures could they actually take on? How would one calculate that? I am a Maths Numpty. Cheers.

 

[Stormonu]

I'd say treat it as if they were about 4th level characters or so for an XP budget.

I based that guess on taking the total HP for a group of 4 CR 6-7 monsters (160 hp x 4 = 640), then dividing it by 3 (est. how long a combat is supposed to last on average), then dividing it by 8 (number of "average" encounters during a day). That gave me 26 - so I checked to see what CR monster does around that damage per round - which is CR 3). Then gave them a bump for being PCs in this case (and having access to HD for healing). What that basically tells me is supposedly how long they'd last before an adventuring day wipes them out.

 

[Paul Farquhar]

Those tabaxi are fast as lightning.

 

[rgoodbb]

I'd say treat it as if they were about 4th level characters or so for an XP budget.

I based that guess on taking the total HP for a group of 4 CR 6-7 monsters (160 hp x 4 = 640), then dividing it by 3 (est. how long a combat is supposed to last on average), then dividing it by 8 (number of "average" encounters during a day). That gave me 26 - so I checked to see what CR monster does around that damage per round - which is CR 3). Then gave them a bump for being PCs in this case (and having access to HD for healing). What that basically tells me is supposedly how long they'd last before an adventuring day wipes them out.

Thanks for your time and work! Would you be able to calculate for me maybe 3 hard to deadly encounters within a day? I don't think I'll get more out of a 1-shot. I'm thinking something along the lines of:

Encounter 1 Minions/guards/swarms
Encounter 2 Bodyguards/Lieutenants
Encounter 3 Boss type battle

 

[Paul Farquhar]

I would treat the monstrous PCs as if they where 4 character levels higher than the monster's CR. In other words, design the encounter as if it was a level 10-11 party.

 

[rgoodbb]

Many thanks! Now to choose from:

• Blue Abashi
• Chimera
• Dhergoloth
• Lost Sorrowsworn
• Medusa
• Mind Flayer
• Oni
• Shadow Dancer
• Shield Guardian
• Venom Troll
• White Slaad
• Yuan-Ti Abomination

This is gonna' be fun!

 

[Stormonu]

I'm thinking you're going to want about three CR 7 battles, with last being CR 8 or so.

Encounter 1 - 8 CR 2 creatures
Encounter 2 - 4 CR 6 creatures
Encounter 3 - 1 CR 7 or 8 creature (MUST have Legendary actions) & 2 CR 3 bodyguards

This assumes the party doesn't get a chance to rest to heal and recover between fights. If they're allowed to fully rest and recover for the last fight, you're probably going to want something around CR 12-13 for the final fight (again, it will need Legendary actions, and maybe a couple CR 4-5 minions as well)

 

[Quickleaf]

If I want to have my 4-5 players be CR 6-7 monsters for a 1-shot (an Oni, a Shadow Dancer etc.), what CR rating/budget would the actual monsters be? What creatures could they actually take on? How would one calculate that? I am a Maths Numpty. Cheers.

I echo @Paul Farquhar's estimate (treating them as 9th - 11th level PCs for encounter building seems about right).

Huge flaws with CR aside (and variability amongst monsters themselves), my process would be to take 4 Onis (CR 7), which have a total XP value of 11,600.
Then look at which level a 4-person party's "Deadly" threshold is close to that, e.g. 9th level defines deadly as 9,600 XP+, 10th level as 11,200 XP+, and 11th level as 14,400 XP+.