The title is not really true. I just want to rant.
Based on my experience, and the opinions of various DMs on Youtube, challenge rating is a deeply unreliable system. However, I have also found that players expect me to adhere to the challenge rating guidelines. At the same time, these players don't seem to know much about challenge rating. For instance, after a party lost a fight with two shambling mounds, one player said that a shambling mound is a boss monster. Sure, in that one popular module, the shambling mound will decimate the party. But in a level 7 party, 2 shambling mounds is a "hard" encounter, according to CR guidelines. I put that defeat down to a party of ranged combatants standing next to the hard-thumping monsters.
As a DM, I hate it when players ask about challenge rating.
As a player, I've been in at least three fights against a supposedly devastating enemy that turned out to be easy. (I've also been in a near-TPK against a less difficult enemy. We rolled badly.) The "deadly" fights became easy because of smart tactics and simple weight of numbers. Each fight was four or five characters against one high-level monster. In each case, the DM was surprised at how short the fight was.
I mostly use CR to compare one monster to another. Aside from that, it's not great. Just about the fastest way to make me angry is to ask "What CR is this creature?"
I want to get into the Jim Murphy school of TPKs with kobolds.
CR is fairly unreliable for a specific group of PCs and Players as 1) a good or bad day with the dice can swing even an easy fight into deadly territory, or a deadly fight into easy territory, 2) more advanced and tactical players will be able to exploit their character's abilities and a creatures weaknesses beyond game balance (this can border on metagaming if you are not careful), 3) any homebrew elements you introduce will have an adverse affect on the balancing of encounters that might make the "standard" not align with what is reasonable, and 4) the game is built on a certain amount of resources being used over an adventuring day, so the first encounter of the day will be easier, even if it is "deadly" than the same encounter after the group has expended some of their resources.
But all of that aside, I would never tell the party the CR of the creatures they face. It isn't a useful metric for players, and a players expectation for the game should not be built around seeing monsters of a certain CR. The only reason they would need to know the CR at all is to use as a calculator of XP (if you use XP progression). You can get around that by just calculating the XP yourself (which you should be doing anyway)
If players complain about the CR of monsters they're facing, take away their Monster Manual. Or just rename and re-skin the monsters you use so they don't know what they're up against. That's metagaming.
If players think it's "unfair" to attack with a higher CR monster than their level, then their mindset is one of an adversarial game of players vs. DM. The rules are there to help everybody have fun, not to make sure the DM doesn't beat the players. And choice of CR isn't a rule, anyway, just a guideline.
As a contrary opinion, I've found that CR ratings are a good indicator of what a party can handle. Just an indicator, of course, as every party is different.
With a few "but" comments…
But… it applies less the higher the tier of the characters.
But… it applies less when you have five PCs, and isn't much use with six or seven PCs.
(This is a big one) But… it applies less and less due to the power creep of additional books. I'm noticing that the CR calculations are wonky with PCs built using Xanathar's (and really wonky with Tasha's). Those PCs are noticeably more powerful than PHB-only PCs.
CR can only ever at best be a kind of guideline. It is useful at extremes (level 3 party will not win against a CR15 monster), and useless when differentiating between CR6 and CR7, or CR9 and CR10, for example. There's no way of knowing what magic items, feats, terrain, and so on will influence the battle.
Last session my players (5 x level 8 characters) launched a suicidal assault on an airship. They took on the CR15 campaign boss alongside 7 CR3 swarms and 4 CR4 monsters, and won the encounter (made the boss flee after they dealt him 250 damage in 3 turns, escaped the rest, blew up the airship). They are pretty min-maxed with feats and have some powerful items (including one Very Rare item), but the CR was totally out the window.
One of the reasons CR seems to err too much on the side of super easy encounters is that it is built around the idea of the 6-8 encounter adventuring day. That is to say, the developers imagined players would have between 6 and 8 encounters that, while not strictly combat, would gradually consume player resources (hp, spell slots, SR/LR abilities, items, etc) throughout the in-game day, effecting the difficulty of encounters depending on when in the day they were faced and how many resources the players had spent leading up to it.
Many tables, however, do not play for 8 hours at a time like they did back in the old days. Most people only have about 3-4 hours to play on maybe one or two nights a week, and the result of these limited sessions is that players face fewer encounters, with only about 1 of them being combat per session. Players therefore have more resources at their disposal going into most combat encounter, and are able to "go nova" and blow all their high- level abilities in that one battle often without having to worry about what's next because a long rest is usually (not always, but usually) waiting at the end of the session.
There are two ways you can get around this, and you can use either method when it suits you.
1: you can through higher CR monsters at your players than the rules designate for their level and use your best judgement to keep from going overboard with it and killing your players with a truly unfair encounter (this part is admittedly more art than science, but gets easier the more you DM). My rule of thumb for this is I don't usuallly do monsters more than 3 or 4 CR's up from the players level, or I take note of how much damage the monster does and don't pick anything that can two-shot your tank.
2. This works better in dungeon crawl scenarios, but you just have an adventuring day take multiple sessions, that way the session time limit doesn't limit encounters and difficulty should remain more consistent. The only thing to watch for here is that players are going to want to long rest after every encounter, especially when it's been 3 weeks since your last IRL long rest. Players like having access to all their abilities and it's smart to long rest whenever possible, BUT players also love challenging encounters. So what you need to do is make long rests hard to do. Either dust off the old Morrowind message of "you can't rest here, enemies are nearby" and only let them LR when they've reached pre-determined safe areas, or institute a check for them to secure themselves when preparing a long rest (maybe higher DC depending on where in the dungeon they choose to sleep, how they propose to defend the area, who's keeping watch, etc) and have that check result in a random encounter should they fail it. Also remind your players that they can only benefit from a long rest once per 8 hour period, so if you just long rested and then took a beating, you still can't do it again till the end of the day or else sit around till then in hostile territory and trigger an automatic random encounter.
Those are a few tricks you could use to get around the CR dilemma, though as I said at the beginning there are more factors at play.
Last session my players (5 x level 8 characters) launched a suicidal assault on an airship. They took on the CR15 campaign boss alongside 7 CR3 swarms and 4 CR4 monsters, and won the encounter (made the boss flee after they dealt him 250 damage in 3 turns, escaped the rest, blew up the airship). They are pretty min-maxed with feats and have some powerful items (including one Very Rare item), but the CR was totally out the window.
Well, they did run away without grinding through probably 700 hp in minions, but I suspect a significant number of enemies were unable to effectively engage.
Last session my players (5 x level 8 characters) launched a suicidal assault on an airship. They took on the CR15 campaign boss alongside 7 CR3 swarms and 4 CR4 monsters, and won the encounter (made the boss flee after they dealt him 250 damage in 3 turns, escaped the rest, blew up the airship). They are pretty min-maxed with feats and have some powerful items (including one Very Rare item), but the CR was totally out the window.
Well, they did run away without grinding through probably 700 hp in minions, but I suspect a significant number of enemies were unable to effectively engage.
The enemies were all orcs, so they had Aggressive bonus actions to dash, and all had javelin attacks too. If they'd been forced to fight through all the minions they might have lost (the druid didn't cast a single spell 0.0 ), but I'd thought that the CR15 boss alone would have been too much for them (and had planned him as an encounter if they hadn't gone all kamikaze).
One time my DM placed our group against an army of demons. Somehow we managed to survive and we killed a pretty big number of them as well. I was playing a Druid that originally served Demogorgon and he barely casted any spells.
CR isn't all that bad if all you care about is performance in a simple brawl. It starts getting in trouble when you have a more complicated fight, because it doesn't account for mobility issues (a monster that can't engage isn't dangerous), resistance to CC effects, and other weirder abilities. However, its big problems are
It's scaled for the 6-8 encounter day, and most games simply aren't paced that way, so if you put a CR X against a level X party, it gets whomped.
It's scaled for a false model of PC power; the power difference between a level 1 and a level 20 is much larger than between a CR 1 and a CR 20.
My rule of thumb for tier 2 is (combined CR of monsters) = (combined PC levels)/2, so for a party of 4, one equal-CR per two PCs is about right. By tier 4, optimized PCs can reasonably take on one equal-CR per PC.
CR is a good system if you understand what it is meant to be used for: a generalized baseline for the difficulty of an encounter. The CR calculations also come with a few caveats.
First, they do not account for the relative power level of your party. CR calculations will be easier than their label indicates if your party has access to magic weapons or items that increase spell save DCs, for example. Similarly, if your party is comprised of highly optimized PCs played by veteran players, you may find the calculations lacking.
Second, they assume that you are running a standard adventuring day, which means 6-8 medium or hard combat encounters per day (with less or more depending on the difficulty of the encounters). If you are not running a standard adventuring day (and I imagine many DMs do not) you will find that your party has more than enough resources to pour into deadly encounters to make them much easier than they were intended to be.
For either of these scenarios, I find tweaking the numbers helps. At lower levels, this can be as simple as increasing the PC level by 1 or 2, depending on relative power. Alternatively, I may add an extra "ghost" player. I tend to lean towards this solution if the players use summons or companions, usually adding 1 additional PC to the calculations for any given summon. Either of these solutions will allow you to turn up the dials and use CR system to give you more accurate results.
Lastly, and most importantly, CR calculations are no more than guidelines: an estimate or an approximation. They are not absolute or accurate, and they will never be. You should not rely on them for anything else than a starting point for your encounters. They can't possibly be used to factor in other things that might make your combat more difficult, such as a key resistance that prevents your players from doing as much damage as they might normally, or terrain that makes movement particularly difficult, or alternative objectives that the party must worry about in addition to the deadly dangers of combat. This works in the other direction, too, if the party has some sort of advantage. In general, use the advice on page 84 of the DMG as a guideline for pushing an encounter up or down in difficulty based on the situation.
First thing to keep in mind with CR is that most monsters are only calculated based upon their durability, hit chance (attack modifier), save DC (if they have one) and average damage, this means there are a few things you need to consider:
While average damage in a round might be survivable, a couple of critical hits by a monster could change the dynamic of a fight wildly and quickly. This is why I generally prefer to just use average damage and give monsters bonus effects on a critical hit (usually grappling, pushing or knocking prone if it doesn't already have these abilities on attacks, sometimes something more unusual if it makes sense in the moment).
This calculation doesn't really properly account for conditions that some monsters can inflict, and it often doesn't really account for other ways they can hurt you. For example, CR 1/2 says a shadow should be an easy enemy to defeat, but actually a group of low-level characters can really struggle, and even at higher levels a group of them could kill you out of nowhere, well beyond what their CR of 1/2 indicates (because they can kill you without dealing the damage required).
It absolutely does not account for "perfect storm" scenarios where your abilities align well with a monster's weaknesses, or vice versa – those same shadows are less of a worry in a party with a Cleric with Turn (or Destroy) Undead, but a party without one might struggle against a group. If a player over-specialises in one damage type, they'll struggle if a monster is immune to that type and so-on.
You can see some of the problems for yourself if you try converting player characters to monster stat-blocks; conventional wisdom is that a Barbarian isn't much of a threat for a Wizard unless they start close, yet the challenge rating might suggest otherwise, with the Barbarian getting a CR close to their level while a Wizard might seem too low if you go by the table in the DMG, purely because a Barbarian can cover all five of the criteria (AC, HP, DC, attack mod and damage) quite well, whereas the Wizard having a good save DC doesn't really reflect the true extent of what their spellcasting can do.
Personally I think of CR as more of just a way to narrow down the list of monsters I might choose from; if you've got four level 10 characters then for a moderate single enemy encounter you can grab from the CR 8-12 range, but you should think of it as more of a guideline to help you to find monsters that you might like to use. Absolutely take a closer look at the ones you like, and if necessary modify them or change up the encounter to better match them against your players.
Another thing CR can't account for is preparation and tactics; a dragon played intelligently can be extremely dangerous, after all, why would it land if it has no reason to? And if the players don't know they're going to be facing a dragon, they won't be prepared to counteract fly-by tactics, or lair actions etc., which could make a difficult fight into one that's potentially a total party wipe, or at least one that needs to be run away from. Prepared players can wipe a target many CR levels higher than their group, while unprepared players can see their party ruined by an enemy with strengths they can't easily counter normally. A lich is a potentially highly threatening foe, but not if you have lots of counterspell ability or access to an antimagic field, but on the other hand a lich in a prepared lair with armies of undead may be something players should need to cheese somehow to even stand a chance by the time they get to it.
I think most important of all is to consider what the purpose of the encounter is. Personally for significant fights I'm not as interested in hit-point attrition and trading damage, but about making it more like a puzzle to be solved; for example, maybe the boss is actually relatively weak, but they start out invulnerable, so it's more of a frantic dash to figure out why and how to remove that. Or maybe there are hostages in danger and your primary objective isn't actually to defeat the boss at all, but to save them (or a specific one, or retrieve an item they have etc.). By having other goals in a fight you can change the dynamic. I've made fights basically unwinnable, or not without extreme cost, before purely to remind the players that running away is an option if your objective isn't to kill those enemies.
TL;DR
Treat CR as only a very rough guideline – you can run high CR monsters in ways that make them possible for weaker groups to fight (e.g- split attacks, don't use their big area effects) and can make lower CR monsters threatening in groups or with clever tactics, traps etc. Play with expectations, treat big fights as puzzles, and just generally have fun with it, in the hopes that your players will too. Your goal isn't to defeat them, but to make sure that you all have a good time.
Former D&D Beyond Customer of six years: With the axing of piecemeal purchasing, lack of meaningful development, and toxic moderation the site isn't worth paying for anymore. I remain a free user only until my groups are done migrating from DDB, and if necessary D&D, after which I'm done. There are better systems owned by better companies out there.
I have unsubscribed from all topics and will not reply to messages. My homebrew is now 100% unsupported.
One thing I want to say for the theoretical “average day” and its number of encounters is that I think that’s more a ceiling than an actual average. And CR is supposed to favor players by a solid margin, since even 10 to 1 odds favoring the players isn’t good for a party’s longevity in any kind of campaign that lasts for more than a few sessions.
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The title is not really true. I just want to rant.
Based on my experience, and the opinions of various DMs on Youtube, challenge rating is a deeply unreliable system. However, I have also found that players expect me to adhere to the challenge rating guidelines. At the same time, these players don't seem to know much about challenge rating. For instance, after a party lost a fight with two shambling mounds, one player said that a shambling mound is a boss monster. Sure, in that one popular module, the shambling mound will decimate the party. But in a level 7 party, 2 shambling mounds is a "hard" encounter, according to CR guidelines. I put that defeat down to a party of ranged combatants standing next to the hard-thumping monsters.
As a DM, I hate it when players ask about challenge rating.
As a player, I've been in at least three fights against a supposedly devastating enemy that turned out to be easy. (I've also been in a near-TPK against a less difficult enemy. We rolled badly.) The "deadly" fights became easy because of smart tactics and simple weight of numbers. Each fight was four or five characters against one high-level monster. In each case, the DM was surprised at how short the fight was.
I mostly use CR to compare one monster to another. Aside from that, it's not great. Just about the fastest way to make me angry is to ask "What CR is this creature?"
I want to get into the Jim Murphy school of TPKs with kobolds.
"What CR are these?!"
"1/8, sucker!"
CR is fairly unreliable for a specific group of PCs and Players as 1) a good or bad day with the dice can swing even an easy fight into deadly territory, or a deadly fight into easy territory, 2) more advanced and tactical players will be able to exploit their character's abilities and a creatures weaknesses beyond game balance (this can border on metagaming if you are not careful), 3) any homebrew elements you introduce will have an adverse affect on the balancing of encounters that might make the "standard" not align with what is reasonable, and 4) the game is built on a certain amount of resources being used over an adventuring day, so the first encounter of the day will be easier, even if it is "deadly" than the same encounter after the group has expended some of their resources.
But all of that aside, I would never tell the party the CR of the creatures they face. It isn't a useful metric for players, and a players expectation for the game should not be built around seeing monsters of a certain CR. The only reason they would need to know the CR at all is to use as a calculator of XP (if you use XP progression). You can get around that by just calculating the XP yourself (which you should be doing anyway)
If players complain about the CR of monsters they're facing, take away their Monster Manual. Or just rename and re-skin the monsters you use so they don't know what they're up against. That's metagaming.
If players think it's "unfair" to attack with a higher CR monster than their level, then their mindset is one of an adversarial game of players vs. DM. The rules are there to help everybody have fun, not to make sure the DM doesn't beat the players. And choice of CR isn't a rule, anyway, just a guideline.
As a contrary opinion, I've found that CR ratings are a good indicator of what a party can handle. Just an indicator, of course, as every party is different.
With a few "but" comments…
But… it applies less the higher the tier of the characters.
But… it applies less when you have five PCs, and isn't much use with six or seven PCs.
(This is a big one)
But… it applies less and less due to the power creep of additional books. I'm noticing that the CR calculations are wonky with PCs built using Xanathar's (and really wonky with Tasha's). Those PCs are noticeably more powerful than PHB-only PCs.
CR can only ever at best be a kind of guideline. It is useful at extremes (level 3 party will not win against a CR15 monster), and useless when differentiating between CR6 and CR7, or CR9 and CR10, for example. There's no way of knowing what magic items, feats, terrain, and so on will influence the battle.
Last session my players (5 x level 8 characters) launched a suicidal assault on an airship. They took on the CR15 campaign boss alongside 7 CR3 swarms and 4 CR4 monsters, and won the encounter (made the boss flee after they dealt him 250 damage in 3 turns, escaped the rest, blew up the airship). They are pretty min-maxed with feats and have some powerful items (including one Very Rare item), but the CR was totally out the window.
One of the reasons CR seems to err too much on the side of super easy encounters is that it is built around the idea of the 6-8 encounter adventuring day. That is to say, the developers imagined players would have between 6 and 8 encounters that, while not strictly combat, would gradually consume player resources (hp, spell slots, SR/LR abilities, items, etc) throughout the in-game day, effecting the difficulty of encounters depending on when in the day they were faced and how many resources the players had spent leading up to it.
Many tables, however, do not play for 8 hours at a time like they did back in the old days. Most people only have about 3-4 hours to play on maybe one or two nights a week, and the result of these limited sessions is that players face fewer encounters, with only about 1 of them being combat per session. Players therefore have more resources at their disposal going into most combat encounter, and are able to "go nova" and blow all their high- level abilities in that one battle often without having to worry about what's next because a long rest is usually (not always, but usually) waiting at the end of the session.
There are two ways you can get around this, and you can use either method when it suits you.
1: you can through higher CR monsters at your players than the rules designate for their level and use your best judgement to keep from going overboard with it and killing your players with a truly unfair encounter (this part is admittedly more art than science, but gets easier the more you DM). My rule of thumb for this is I don't usuallly do monsters more than 3 or 4 CR's up from the players level, or I take note of how much damage the monster does and don't pick anything that can two-shot your tank.
2. This works better in dungeon crawl scenarios, but you just have an adventuring day take multiple sessions, that way the session time limit doesn't limit encounters and difficulty should remain more consistent. The only thing to watch for here is that players are going to want to long rest after every encounter, especially when it's been 3 weeks since your last IRL long rest. Players like having access to all their abilities and it's smart to long rest whenever possible, BUT players also love challenging encounters. So what you need to do is make long rests hard to do. Either dust off the old Morrowind message of "you can't rest here, enemies are nearby" and only let them LR when they've reached pre-determined safe areas, or institute a check for them to secure themselves when preparing a long rest (maybe higher DC depending on where in the dungeon they choose to sleep, how they propose to defend the area, who's keeping watch, etc) and have that check result in a random encounter should they fail it. Also remind your players that they can only benefit from a long rest once per 8 hour period, so if you just long rested and then took a beating, you still can't do it again till the end of the day or else sit around till then in hostile territory and trigger an automatic random encounter.
Those are a few tricks you could use to get around the CR dilemma, though as I said at the beginning there are more factors at play.
Well, they did run away without grinding through probably 700 hp in minions, but I suspect a significant number of enemies were unable to effectively engage.
The enemies were all orcs, so they had Aggressive bonus actions to dash, and all had javelin attacks too. If they'd been forced to fight through all the minions they might have lost (the druid didn't cast a single spell 0.0 ), but I'd thought that the CR15 boss alone would have been too much for them (and had planned him as an encounter if they hadn't gone all kamikaze).
One time my DM placed our group against an army of demons. Somehow we managed to survive and we killed a pretty big number of them as well. I was playing a Druid that originally served Demogorgon and he barely casted any spells.
CR is a very loose guidline at best. It's ok to get a first impression, but never a reliable way to design encounters.
+ Instaboot to murderhobos + I don't watch Critical Role, and no, I really shouldn't either +
Then how do I design encounters? Do I just look at their abilities then at the ones my players have?
CR isn't all that bad if all you care about is performance in a simple brawl. It starts getting in trouble when you have a more complicated fight, because it doesn't account for mobility issues (a monster that can't engage isn't dangerous), resistance to CC effects, and other weirder abilities. However, its big problems are
My rule of thumb for tier 2 is (combined CR of monsters) = (combined PC levels)/2, so for a party of 4, one equal-CR per two PCs is about right. By tier 4, optimized PCs can reasonably take on one equal-CR per PC.
CR is a good system if you understand what it is meant to be used for: a generalized baseline for the difficulty of an encounter. The CR calculations also come with a few caveats.
First, they do not account for the relative power level of your party. CR calculations will be easier than their label indicates if your party has access to magic weapons or items that increase spell save DCs, for example. Similarly, if your party is comprised of highly optimized PCs played by veteran players, you may find the calculations lacking.
Second, they assume that you are running a standard adventuring day, which means 6-8 medium or hard combat encounters per day (with less or more depending on the difficulty of the encounters). If you are not running a standard adventuring day (and I imagine many DMs do not) you will find that your party has more than enough resources to pour into deadly encounters to make them much easier than they were intended to be.
For either of these scenarios, I find tweaking the numbers helps. At lower levels, this can be as simple as increasing the PC level by 1 or 2, depending on relative power. Alternatively, I may add an extra "ghost" player. I tend to lean towards this solution if the players use summons or companions, usually adding 1 additional PC to the calculations for any given summon. Either of these solutions will allow you to turn up the dials and use CR system to give you more accurate results.
Lastly, and most importantly, CR calculations are no more than guidelines: an estimate or an approximation. They are not absolute or accurate, and they will never be. You should not rely on them for anything else than a starting point for your encounters. They can't possibly be used to factor in other things that might make your combat more difficult, such as a key resistance that prevents your players from doing as much damage as they might normally, or terrain that makes movement particularly difficult, or alternative objectives that the party must worry about in addition to the deadly dangers of combat. This works in the other direction, too, if the party has some sort of advantage. In general, use the advice on page 84 of the DMG as a guideline for pushing an encounter up or down in difficulty based on the situation.
First thing to keep in mind with CR is that most monsters are only calculated based upon their durability, hit chance (attack modifier), save DC (if they have one) and average damage, this means there are a few things you need to consider:
You can see some of the problems for yourself if you try converting player characters to monster stat-blocks; conventional wisdom is that a Barbarian isn't much of a threat for a Wizard unless they start close, yet the challenge rating might suggest otherwise, with the Barbarian getting a CR close to their level while a Wizard might seem too low if you go by the table in the DMG, purely because a Barbarian can cover all five of the criteria (AC, HP, DC, attack mod and damage) quite well, whereas the Wizard having a good save DC doesn't really reflect the true extent of what their spellcasting can do.
Personally I think of CR as more of just a way to narrow down the list of monsters I might choose from; if you've got four level 10 characters then for a moderate single enemy encounter you can grab from the CR 8-12 range, but you should think of it as more of a guideline to help you to find monsters that you might like to use. Absolutely take a closer look at the ones you like, and if necessary modify them or change up the encounter to better match them against your players.
Another thing CR can't account for is preparation and tactics; a dragon played intelligently can be extremely dangerous, after all, why would it land if it has no reason to? And if the players don't know they're going to be facing a dragon, they won't be prepared to counteract fly-by tactics, or lair actions etc., which could make a difficult fight into one that's potentially a total party wipe, or at least one that needs to be run away from. Prepared players can wipe a target many CR levels higher than their group, while unprepared players can see their party ruined by an enemy with strengths they can't easily counter normally. A lich is a potentially highly threatening foe, but not if you have lots of counterspell ability or access to an antimagic field, but on the other hand a lich in a prepared lair with armies of undead may be something players should need to cheese somehow to even stand a chance by the time they get to it.
I think most important of all is to consider what the purpose of the encounter is. Personally for significant fights I'm not as interested in hit-point attrition and trading damage, but about making it more like a puzzle to be solved; for example, maybe the boss is actually relatively weak, but they start out invulnerable, so it's more of a frantic dash to figure out why and how to remove that. Or maybe there are hostages in danger and your primary objective isn't actually to defeat the boss at all, but to save them (or a specific one, or retrieve an item they have etc.). By having other goals in a fight you can change the dynamic. I've made fights basically unwinnable, or not without extreme cost, before purely to remind the players that running away is an option if your objective isn't to kill those enemies.
TL;DR
Treat CR as only a very rough guideline – you can run high CR monsters in ways that make them possible for weaker groups to fight (e.g- split attacks, don't use their big area effects) and can make lower CR monsters threatening in groups or with clever tactics, traps etc. Play with expectations, treat big fights as puzzles, and just generally have fun with it, in the hopes that your players will too. Your goal isn't to defeat them, but to make sure that you all have a good time.
Former D&D Beyond Customer of six years: With the axing of piecemeal purchasing, lack of meaningful development, and toxic moderation the site isn't worth paying for anymore. I remain a free user only until my groups are done migrating from DDB, and if necessary D&D, after which I'm done. There are better systems owned by better companies out there.
I have unsubscribed from all topics and will not reply to messages. My homebrew is now 100% unsupported.
One thing I want to say for the theoretical “average day” and its number of encounters is that I think that’s more a ceiling than an actual average. And CR is supposed to favor players by a solid margin, since even 10 to 1 odds favoring the players isn’t good for a party’s longevity in any kind of campaign that lasts for more than a few sessions.