I have been told that CR ratings aren't accurate and while I have believed they aren't perfect, I also still continued to use them.

Recently our DM wanted us to be captured by some bounty hunters, so he put together a crazy hard encounter with an Assassin, gladiator and two thugs. We are a 7th level party of three adventurers, a sorcerer, shadow monk and barbarian. The barbarian was asleep the whole encounter thanks to "plot poison" as our DM calls it.

We smoked them, the DM wasn't pulling punches either. Two 7th level characters smoked a beyond deadly encounter.

I don't want this to happen in my campaign and I want to know how you guys balance encounters.

TLDR: CR sucks, what do you use instead?

To answer you question: CR.

I would suggest some expectation management when using the encounter creation guidelines and some assumptions about it. 

Deadly. A deadly encounter could be lethal for one or more player characters. Survival often requires good tactics and quick thinking, and the party risks defeat.

There is nothing in this description that definitively states that a PC *will* be killed, only that it *could* be lethal for one or more PCs. It then outlines that tactics and improvisation are variables that are too vast to enclude when building encounters. Simply put, we are working with probability. Not with definite outcomes. The dice we roll to determine a hit, or a save work to provide the chaotic nature of battle. Multiply that by the number of individual ideas and tactics presented by the players and there is no sure fire way to define the outcome without quantum computers and AI. Unless you have some narrative stop-gap, like "plot poison". (Another tangent altogether.)

The other frequently missed assumption is that there be somewhere in the ballpark of 6-8 medium to hard encounters per adventuring day. This assumes that the party will eventually be depleted of resources, unable to heal during combat, unable to leverage abilities and features that assist in generating combat power. They're gonna run outta gas eventually. And when they do, they are susceptible to being brought down by Kobolds. 

Lastly, PC tactics are as much a variable as monster tactics and environmental hazards. If played more optimally, some groups of monsters can be unforgiving to even Tier 2 parties. I've recently experienced a party of 5 x LVL 5 nearly wipe from 5 kobolds in a cave while stuck in quicksand, and party of 4 x LVL 7 TPK with an Orcish war band in the open wilderness. Understand that this isn't because of some vast tactical ability that I possess, but some of the burden falls on the party not responding very well to the information presented to them and maybe making some tactical missteps that cost them dearly.

I tend to use multi-part encounters at higher levels and at times, monster awareness dependent, focus fire on a PC to make the party focus on survivability more than combat power. Get a PC close to 0 HP or knock them out of combat, and the whole dynamic of the fight can shift drastically. Make the fight about something other than hit points. Give the PCs a goal besides "hit it till it dies". Battles can be won, and that force can still loose the overall war. Monsters will play to win, just like the PCs will. But at the end of the combat, the party should feel like they had to overcome a challenge to be standing and successful.

Quote from Kaavel >>

To answer you question: CR.

I would suggest some expectation management when using the encounter creation guidelines and some assumptions about it. 

Deadly. A deadly encounter could be lethal for one or more player characters. Survival often requires good tactics and quick thinking, and the party risks defeat.

There is nothing in this description that definitively states that a PC *will* be killed, only that it *could* be lethal for one or more PCs. It then outlines that tactics and improvisation are variables that are too vast to enclude when building encounters. Simply put, we are working with probability. Not with definite outcomes. The dice we roll to determine a hit, or a save work to provide the chaotic nature of battle. Multiply that by the number of individual ideas and tactics presented by the players and there is no sure fire way to define the outcome without quantum computers and AI. Unless you have some narrative stop-gap, like "plot poison". (Another tangent altogether.)

The other frequently missed assumption is that there be somewhere in the ballpark of 6-8 medium to hard encounters per adventuring day. This assumes that the party will eventually be depleted of resources, unable to heal during combat, unable to leverage abilities and features that assist in generating combat power. They're gonna run outta gas eventually. And when they do, they are susceptible to being brought down by Kobolds. 

Lastly, PC tactics are as much a variable as monster tactics and environmental hazards. If played more optimally, some groups of monsters can be unforgiving to even Tier 2 parties. I've recently experienced a party of 5 x LVL 5 nearly wipe from 5 kobolds in a cave while stuck in quicksand, and party of 4 x LVL 7 TPK with an Orcish war band in the open wilderness. Understand that this isn't because of some vast tactical ability that I possess, but some of the burden falls on the party not responding very well to the information presented to them and maybe making some tactical missteps that cost them dearly.

I tend to use multi-part encounters at higher levels and at times, monster awareness dependent, focus fire on a PC to make the party focus on survivability more than combat power. Get a PC close to 0 HP or knock them out of combat, and the whole dynamic of the fight can shift drastically. Make the fight about something other than hit points. Give the PCs a goal besides "hit it till it dies". Battles can be won, and that force can still loose the overall war. Monsters will play to win, just like the PCs will. But at the end of the combat, the party should feel like they had to overcome a challenge to be standing and successful.

 Thanks, This has helped a lot.

Quote from Roguish_Archer >>

I have been told that CR ratings aren't accurate and while I have believed they aren't perfect, I also still continued to use them.

Recently our DM wanted us to be captured by some bounty hunters, so he put together a crazy hard encounter with an Assassin, gladiator and two thugs. We are a 7th level party of three adventurers, a sorcerer, shadow monk and barbarian. The barbarian was asleep the whole encounter thanks to "plot poison" as our DM calls it.

We smoked them, the DM wasn't pulling punches either. Two 7th level characters smoked a beyond deadly encounter.

I don't want this to happen in my campaign and I want to know how you guys balance encounters.

TLDR: CR sucks, what do you use instead?

To be honest, that sounds like poor setup (an assassin is designed for surprise attacks, so pairing it with monsters that don't even have stealth seems like a bad plan) or bad luck; I would normally expect total CR equal to total party level to be a wipe. My usual rule of thumb is that total CR equal to half of total party levels is a tough but usually winnable fight (this is way into the Deadly range; if you're not running six encounters per day, you can basically double the xp budgets and the descriptions will become reasonably accurate).

I have been mostly been using CR as calculated in the quick encounter tables Xanathar's guide to everything, with them as they are plus a gimmick for the fight or calculating as if there were 50% more PC for a more challenging encounter. It seems to work so far, as long as I make sure the opposing side has as many or more actions a turn as the party. We are also at a point of the plot where one of the PC was captured and mindcontroled so I calculated its CR as if it were a monster to plot the encounter and it seemed to match the values given.

Honestly there will never be a conclusive way to rate creatures without serious in-depth valuation of every ability against every other one (IE, not going to happen).

How different would that story have been if those thugs, gladiators and assassin had been aarakokra, and had therefore been flying? No change to CR, but you probably would have been captured a lot easier!

To avoid this in your own game, use the CR as a guide, then perhaps adjust for how much your fight is playing into the parties hands. An easy encounter with kobolds could become a slaughter if the party is melee based and the kobolds have wings.

The DM sounds like they did this - knocking out the barbarian to make their all-melee thug gang more likely to survive, but they haven't given you anything which is a challenge beyond their hitpoints and damage output. You probably expended a lot of resource to win, and the enemy just walked right up to you in a predictable manner and started hitting you. One good control spell and the encounter becomes "throw stuff at the enemy until they die". If you want to challenge the PC's, first think of what sort of enemy/encounter will be challenging (IE a spellcaster, or a flying ranged one, or an ambush, or a chase sequence), then pick the challenging enemies, then adjust to CR. A pack of melee-centric enemies attacking melee-centric players will usually fall on the player side, especially if they have any spells to use!

I use the Encounter Builder and filter my monsters by CR, usually going from -2 party level to double party level (so my 4 level 5 players are seeing from 3 to 10 CR enemies) .  It's a bit of a slow process, but I am working encounters to more directly counter the party's strengths to keep challenge up, while paying very little attention to the overall rating "Deadly, Hard, etc)  I am picking monsters by looking at stat blocks and seeing what they can do, then considering, based on what they HAVE done, how my party will try to handle this setup.

I have several "Summoner" type encounters coming, where an item will be set by an enemy leader and it will summon/spawn/teleport in reinforcements, which will be trash mobs, just to help rebalance Action Economy of the party.  My last couple encounters turned into what you described, the party smoked them, much easier than I expected.  I have tweaked the next ones to come, to exploit weaknesses I saw in their tactics and play a little against their greatest strengths.  As I better see what tactics and abilities they struggle with, it becomes easier to create challenging encounters they can handle, but still face risk if the make a few silly mistakes.  On the flip side of the balancing by adding monsters, the first Dragon type creature I threw at them, I had to nerf one attack round of my Dragon, as if it had used it's Breath weapon, I had a TPK, even with saves made.  Oops, may have bring the giant lizard a tad early.

I sort of use CR as a rough guide because after many sessions I now have a rough idea of what my groups can handle and what their weaknesses are (Their weakness is any enemy that uses strategy).

Of course in the right situation, even low CR monsters can prove a threat to high level parties. My level 10 group had to actually flee a gnoll warband consisting of Gnoll, Gnoll Flesh Gnawer's, Gnoll Hunter's, Hyena's, Gnoll Fang of Yeenoghu and Dretch's most of whom have CR's <1 because they rushed in without a plan and got swarmed. 

Unfortunately CR is often falsely lowered for some monsters to make DM's assign them to lower level partys to make encounters with them more epic. One example is the Adult White Dragon, assigned a CR of 13, but the DMG CR calculation puts it at a CR of 17. Even worse for the poor Adult White Dragon, the Adult Copper Dragon has lower hp and deals less damage, but gets a CR of 14.

You really just need to do it by knowing your characters, and choosing or building the monsters yourself.

The fight you mentioned was always going to be a bop, that just shows the DM crafting it doesn't understand encounter design and maybe just looked at CR rather than reading the monsters and considering their abilities. In case this helps for the future, here's a breakdown of why it was so easy:

The Assassin has weak AC (a level 1 character with +3 ability score still hits it more than 50% of the time), adequate hit points, and Evasion, which may have no impact on the fight at all. Its CR8 is only justified by the assassination abilities and poison. If the assassin does not go first in the combat, and has not surprised your party, or is otherwise unable to gain advantage then it will only deal 31 damage with a light crossbow, at 80 feet range or less. It should not be attacking up close, not with that poor AC. 31 damage is easily shrugged off at level 7.

The Gladiator has 3 attacks but only deals 11 damage per attack. It has little offensive capability against level 7 characters. Its CR5 is because of its meaty hit points and with Parry it can get an AC of 19. But tankiness isn't that useful when you have a damage output of about 22 per turn. The gladiator is probably about an even match for a well designed Fighter or Barbarian of the same level.

The Thugs provide nothing in the encounter except to give advantage to Sneak Attacks, so really this was a 2-on-2 combat. Popping all your alpha-strike abilities, the assassin can easily be dropped in a turn if it isn't being played correctly, and since they were lined up as bounty hunters rather than trying to actually assassinate your party while they slept, I'd say that the DM was basically neutering the monsters by putting them into an unfavourable environment.

The DM designing the encounter needs to take into account what will happen if the characters win initiative and lock down one or more enemies with spells like Hold Person. If the Gladiator is locked out, the thugs are meaningless and the assassin - which should be played as taking one shot from stealth and then hiding and fleeing, returning again days later for another single shot - is now a sitting duck. And as soon as one enemy is downed, the entire fight is a walkover.

Quote from Roguish_Archer >>

I have been told that CR ratings aren't accurate and while I have believed they aren't perfect, I also still continued to use them.

Recently our DM wanted us to be captured by some bounty hunters, so he put together a crazy hard encounter with an Assassin, gladiator and two thugs. We are a 7th level party of three adventurers, a sorcerer, shadow monk and barbarian. The barbarian was asleep the whole encounter thanks to "plot poison" as our DM calls it.

We smoked them, the DM wasn't pulling punches either. Two 7th level characters smoked a beyond deadly encounter.

I don't want this to happen in my campaign and I want to know how you guys balance encounters.

TLDR: CR sucks, what do you use instead?

  It's worth remembering that the CR and encounter scaling is built for multiple encounters with only a short rest in between encounters. For a single encounter, the composition indeed rack up to be deadly, but over the course of an adventuring day, you've only using ~50% of the adjusted XP for 2 characters at 7th level - so in essence, you'd be expected to roll onto a similar or multiple encounters after with only a short rest (pg 84 DMG). 

Quick and dirty math, I aim for Team Monster having roughly the same number of attacks as the party, and each attack should be able to reduce a PC's HP by about 1/3. A large "setpiece" spell might deal that level of damage or a bit more to the whole party. That's usually a good starting point and then I adjust things depending on how the party handles it.

The other part to address is that single encounter days just don't work. The amount of firepower you need to truly challenge a party when they can blow all their resources in one fight is so high that you can easily TPK them depending on how the dice go - and the smaller a party is, the more swingy this can be. The game was just not designed for that. 6-8 encounters a day is not realistic in most cases, but you really should be aiming for at least 3-4. And on days where they only have one fight, just get used to the idea that it's not going to be a hard one. They don't all have to be.

You silly nerds and your balance, when I dm I just throw a bunch of random crap at my players and hope they survive. The real way to plan an encounter

Ooo I wanna play that way with you

I cheat.

Not all the time. Often they get what I planned, and that's it.

But if I want it cinematic and cool, if I want to push it as hard as possible, I will have baked in some options. I want to have the freedom of going crazy without accidentally wiping the party just because I misjudged.

Players had a fight with a dragon it its lair. Black pools of water all over the place. Two of the dragon's spawn, wyrmlings, burst out of the water. Cool surprise! Mutliple targets! Much heroism! Derring do was done!

Turned out great, three of the players (out of 6) were at zero hp at some point. But! ... who knows how many wyrmlings were in there?

Not me, that's for sure.

If the fight had been too easy, I'd have thrown in another critter. Two more, even. Whatever made it fun.

--

Another fight: them vs the infinite horde of ghouls. They needed to escape to the church where the ghouls couldn't follow. Egads! The door is locked! Quick, make a battle line aorund the rogue while he picks the lock! Throw down covering fire for the barbarian who is three turns of furious combat away from the party! WILL WE MAKE IT IN TIME?!

They did. Just. It was epic. But guess what? The NPC acolyte cowering in their room could have come unlocked the door if it was getting hairy. And hmmmm, it's possible that acolyte had a neckalce of prayer beads somewhere around here...

Great that the players made it, and I'm always willing to kill 'em if they do something dopey, but if I want to set them against fights that - through no fault of their own - could go terribly wrong with some bad dice rolls, then yeah, I cheat.

Balanced fights with no DM shennanigans are the bread and butter.

...but cinematic-awesome is the gravy, and that needs a bit of insurance.

CR works for what it's designed to be - a guideline.  There's just so many factors in 5th ed that contribute to how hard an encounter is going to be, it's never going to be a perfect system.  I've nearly killed players with "easy" encounters and had them blow up the theoretically harder ones.  You just never know how it's going to go.  The fighter could miss 3 attacks in a row, the rogue could get a lucky crit on the big bad, the important casting monster is just slightly out of the party's reach for one turn and gets to free cast, etc.  Upping the difficulty and giving fewer encounters per day makes things even swingier.

There are a lot of things they could have done to make CR are more rigorous system.  More aggressive scaling in AC, damage, and HP.  Longer fights in general to smooth out dice variance.  Defined monsters roles to make it clear how the monster should be used in a fight.  These were all things they did in 4th edition, and they weren't as popular.  I'm not saying 4th ed was better - I quite like 5th edition.  But all the streamlining they did definitely made encounter design harder.

Overall though, I don't stress about it too much.  PCs are pretty strong in 5th ed, so I just air on the side of difficult and trust that they'll figure it out.

Enemies with stuff like paralysis can be brutal if there are some unlucky rolls, and useless if their abilities don't go off. I've thrown some Banshees at them at low level, but they've never once failed a save against them, so they don't know what a Banshee even does, really. But it doesn't take much of a swing to see a Banshee take down half the party.

D&D (thanks to that d20) has always struggled a bit with the swings.

Gawd, I remember... I think it was the Ye Olde Red Box? In the intro pre-made adventure, the first monster players could meet was a carrion crawler, with multiple attacks (maybe I'm remembering that wrong) which could paralyse its target, and in those rules any hit on a paralysed target killed it instantly.

God knows how many new players and even whole parties were eaten by that thing.

Sure I use CR. What I don’t use is gimmick monsters. The intellect devourer, beholder, and mind flayer are perfect examples. I recognize that the last two are iconic and all, but the beholder can literally just fly into a corner and win the fight while just taking some piercing damage and the mind flayer can melt PC’s brains very quickly at the level they’re meant to be encountered.