© Wizards of the Coast by Chris Rahn

This Is How To Use CR (Challenge Rating) Effectively in D&D 5e

What Is Challenge Rating in D&D 5e?

In Dungeons & Dragons 5th edition, Challenge Rating, or CR, is the numerical system used to determine a party of four players’ difficulty in defeating an enemy.

Challenge Ratings range from 0 to 30 and includes 1/8, 1/4, and 1/2 ratings. CR is the very basics of calculating battle difficulty and should be used as a baseline to build on.

Challenge Rating is often an overly simplified system, so it shouldn’t be treated as a be-all-end-all determination of whether or not players can handle a situation.

As always, defer to your intuition as a DM as to whether or not the fight needs to be scaled up or down. Improperly balanced parties, for instance, one with no healing spells, may not stand up to an enemy with a lot of long-term damage capabilities.

Conversely, an enemy with high burst damage will ravage a team of squishy players.

How To Calculate CR

Calculating the CR of an encounter is essential for creating a compelling storyline for your players to interact with. If encounters are too easy, players may become bored with the story.

If the encounters are too difficult, the players may become discouraged or stop having fun.

The most important part of any campaign is that all parties involved are having fun, so don’t be afraid to scale some monsters up or down to make the party feel rewarded for their efforts.

Balancing Encounters Using XP Thresholds

A monster’s CR determines how much Experience or XP they grant, and each character has a budget of XP that they can reasonably handle per day.

The following chart gives the adjusted XP budget for a character per day, based on their level.

LevelAdjusted XP Per Day
1st 300
2nd600
3rd1200
4th1700
5th3500
6th4000
7th5000
8th6000
9th7500
10th9000
11th10500
12th11500
13th13500
14th15000
15th18000
16th20000
17th25000
18th27000
19th30000
20th40000

So if I have a party of four 1st level characters, they have an adjusted XP budget of 1200 (300 + 300 + 300 + 300). I can use this as a template to determine what kind of monsters to throw into their encounters.

But it’s more than just a numbers game of the total. An Almiraj is CR 0 and gives 10 XP, but if I throw 120 Almirajs at them… they’ll die (and I will die in real life trying to keep up with an encounter with 124 creatures in it.) 

To break it down, 120 Almirajs will probably each get in about one attack before they die. That’s 120 attacks. About five percent of those will hit since a natural 20 always lands.

Assuming the players even out to about 14 AC overall (with mages being lower and melee classes being higher), the Almirajs have approximately a 60% hit chance (The formula for chance-to-hit is: ((21 – (Target’s AC – Attack Modifier)) / 20 * 100), and the damage is at least 4.

We’ll say this is a well-balanced party with David the wizard, Mary the Sorcerer, Bob the Cleric, and Alice the Barbarian. That’s 52 health at level 1 if they all have maximum Constitution. The Almiraj’s only need to hit 11% of their attacks to achieve a TPK on round 1.

Luckily, Wizards of the Coast have our backs for this one. They’ve also broken the game down into per encounter thresholds for XP. So you can determine the best way to get your party their maximum XP without killing them!

XP Per Encounter Thresholds

The XP Per Encounter Thresholds are precisely what’s written on the tin. They tell the DM how much a player can handle in a single encounter rather than throughout the day.

LevelEasyMediumHardDeadly
1st 255075100
2nd50100150200
3rd75150225400
4th125250375500
5th2505007501100
6th3006009001400
7th35075011001700
8th45090014002100
9th550110016002400
10th600120019002800
11th800160024003600
12th1000200030004500
13th1100220034005100
14th1250250038005700
15th1400280043006400
16th1600320048007200
17th2000390059008800
18th2100420063009500
19th24004900730010900
20th28005700850012700

As the table suggests, it tells you what kind of encounters will pose the best challenge for your parties.

I generally try to give my parties encounters in the medium to hard zone, but I do have one party that enjoys the challenge of taking on deadly and above encounters.

So using this, we can tell that the 120 Almiraj encounter is way too much for Bob, David, Alice, and Mary. Still, we could break up that Almiraj encounters into 24 encounters of 5 Almiraj’s, and suddenly, the same encounter becomes a much more manageable Medium level encounter, right? Not quite.

Adjusted XP Modifier

When you add monsters to an encounter, you make the encounter more difficult since the higher number of creatures means more damage sources to take down.

The action economy will be affected as well. To get the correct calculation of XP, we need to use XP multipliers for multiple monsters.

Number of MonstersXP Multiplier
1×1.0
2×1.5
3-6×2.0
7-10×2.5
11-14×3.0
15 or more×4.0

Using the XP modifier, we find that 5 Almirajs gets a ×2 boost to 100, and this becomes a deadly encounter to any single 

Encounter Balancing Calculators

The topic of Encounter Balancing has spurred several calculator applications to appear online to ease the process of encounter balancing for DMs. These tools are perfect for newer DMs who will need more help with balancing encounters.

We’ve compiled a list of online calculators that you can use to 

Kobold+ Fight Club

One of the most popular D&D encounter balancing websites is Kobold+ Fight Club. The previous Kobold Fight Club calculator is down, but this is a replacement version of that.

Kobold Fight Club allows you to add characters and monsters to a list and even track their current HP values to see how deadly the encounter has become!

D&D Beyond

D&D Beyond has its encounter builder within the website. The feature is currently in Beta, so expect to see more features added to the tracker in the future!

Kastark

Kastark features an encounter balancing app as well as an initiative tracker on their website. It’s a bit bare-bones compared to Kobold Fight Club and D&D Beyond, but it’s much easier on your computer or phone when running it!

When Do We Use CR?

CR is best used when making encounters on the fly. If your party has already burned through all of your planned encounters, it might be time to pull up Kobold Fight Club on your phone and start throwing enemies at them willy nilly.

You might want to start looking at CR if your encounters regularly prove too easy or challenging for your players. Another important time to look at CR is when your players start to acquire magic items that may tip the scales a bit too far in their favor.

Modifying CR

There are tons of ways to modify CR that DMs can use. Whether it’s bumping stats, granting Legendary actions, giving multiattacks, or changing the dice on some damage values, there’s no shortage of ways of scaling fights up and down even in the heat of battle.

When the Fight Is Too Easy…

If you find that your players are just decimating everything you put before them, don’t be afraid to scale up the fight. There are many ways you can do this within the confines of Wizards’ D20 system.

Fudging the Dice

One way is to start fudging enemy rolls in their favor. By just nudging the dice rolls into the enemies’ favor, the game becomes consistently harder, even if the enemies themselves haven’t changed at all! 

Adding More Enemies to the Encounter

If the encounter is too easy, have an enemy summon reinforcements! This can help increase the difficulty of the encounter by changing the action economy drastically.

Players will have to account for new sources of damage, possibly new types of damage, and new enemies on the map.

Give the Enemies More HP

Giving the enemies more HP can help pad out the damage your party is dealing with enemies without fudging any dice. A good piece of wisdom is that fights should last for as long as they remain fun to play.

Some people don’t even write HP totals for their enemies and just allow the battle to go on for as long as it seems reasonable and as long as the players are still having fun with the fight.

When the Fight Is Too Difficult…

Just End the Fight

An excellent way to end a fight that’s gotten stale and frustrating is just to end it. If you don’t want to fudge the rolls in the players’ favor, you can just have another character intervene for the players.

Perhaps you could have an act of God or a natural disaster occur that ends the fight or even just make the next blow the killing blow, regardless of HP totals.

Fudge the Rolls

You can fudge some rolls in favor of your players. Lower the monster’s saving throws and attack rolls to give your players some leeway to play the game a bit more.

Weaken the Enemy

There are lots of ways you can slide in some weakness to the enemy without fudging the rolls. You could have the enemy incur some kind of curse, have their armor or weaponry break, or even have them be injured by a player’s attack and suffer a weakening effect from it.

Inaccuracies of the Challenge Rating System

The Challenge Rating system isn’t without its flaws. It doesn’t take team composition, individual spell lists, item composition, or things like environmental factors into account when calculating how difficult something is. 

Inaccuracies within the Challenge Rating system will be felt hardest by teams of characters who have an unusual composition.

I personally feel the weight of the CR system’s flaws because my players tend to enjoy running fun, unique compositions that the CR system just can’t account for — and I enjoy running those types of games.

I run a game that takes place in an Elvish Wizards’ school using the 5e system. Naturally, all the player characters are Wizards. At 1st level, my players were able to drop a CR 2 Priest in one round because of their incredibly great damage output, losing only one player (though he was killed in one hit.)

Individually, the Priest was highly deadly to the players. Against a party with less damage output, he would be equally fatal. But Wizards pack some of the most incredible low-level damage in the game. So his squishiness became readily apparent after he was slapped in the face with four first-level spells in a row.

My more standard party of a 6th level Warlock, Druid, Fighter, and Sorcerer were actually able to hold their own against a 20th level Barbarian NPC, though not without copious amounts of struggling.

Challenge Rating is not the ultimate sign of strength. An intelligent party or an unusual combination of classes might take down a stronger enemy or have more trouble with a weaker one. For instance, a single Silence spell can easily take down my Wizard party, and a high-burst, long-range caster would take out my standard party without trouble.

How to Calculate CR for Homebrew Monsters

The rawest truth is that calculating CR for your homebrew monsters will be hard because CR isn’t even remarkably accurate for official Wizard’s content. CR doesn’t take anything besides level into account. It would help if you came up with a CR to ensure your monster block has a proficiency score.

Wizards CR Table

Wizards provided a CR table that gives approximate statistics for a monster of any CR. These statistics show the Challenge Rating for a monster’s Armor Class, Hit Points, Attack Bonus, Damage Per Round, and Save DC. Remember that a 

CRXPProficiencyACHPAttack BonusDPRSave DC
00 or 102131-630-113
1/8252137-3532-313
1/45021336-4934-513
1/210021350-7036-813
120021371-8539-1413
245021386-100315-2013
3700213101-115421-2613
41100213116-130527-3214
51800314131-145633-3815
62300315146-160639-4415
72900315161-175645-5015
83900315176-190751-5616
95000416191-205757-6216
105900416206-220763-6816
117200417221-235869-7417
128400417236-250875-8018
1310000517251-265881-8618
1411500518266-280887-9218
1513000518281-295893-9818
1615000518296-310999-10418
1718000619311-32510105-11019
1820000619326-3401011-11619
1922000619341-35510117-12219
2025000619356-40010123-14019
2133000719401-44511141-15820
2241000719446-49011159-17620
2350000719491-53511177-19420
2462000719536-58011195-21221
2575000819581-62512213-23021
2690000819626-67012231-24822
27105000819671-71513249-26622
28120000819716-76013267-28422
29135000919760-80513285-30222
30155000919805-85014303-32023

But there’s a bit more to the formula than just taking the numbers directly from the table. Using the table, you can calculate your monster’s CR by taking the averages of its actual stats.

Using this method, an enemy has two CR ratings, an offensive one and a defensive one.

Defensive CR

Firstly, we’ll look at calculating a Monster’s Defensive CR. That is how easy it is to kill. The defensive CR is found by taking the average of the CR indicated by its HP and its AC.

So if we start with a monster with 150 HP, that’s CR 6, but if its AC is only 13, then its Defensive CR is three or: (6 + 1) / 2, rounded down.

Offensive CR

Offensive CR is similar. You take the CR indicated by the Damage Per Round and their Attack Bonus and average them, just like your Defensive CR, but with offensive stats.

So if we give our monster a DPR of about 46 and an Attack Bonus of 3, that evens out to a CR of 4 or (7 + 1) / 2, rounded down.

Final CR Calculation

So now that we have the offensive and defensive CR calculated, we have can calculate our CR by taking the average of the offensive and defensive CRs. So our monster’s CR is 3 or (4 + 3) / 2, rounded down. There are a few more considerations to make, though.

CR Multipliers

Several multipliers are added onto the CR based on other factors like resistances and other features which affect the battle.

Expected CRDamage ResistancesDamage Immunities
1-4×2×2
5-10×1.5×2
11-16×1.25×1.5
17+×1×1.25

Flying & Ranged

If a monster is both flying and has attacks that can hit from long range, its effective AC is increased by 2. When you calculate its Defensive CR, you should use the increased AC to calculate.

Saving Throws

Saving Throw proficiencies also affect a monster’s effective AC. All monsters can have 1 or 2 saving throw proficiencies without changing their CR. If it has 3 or 4 proficiencies, increase its effective AC by 2. If it has 5 or 6 proficiencies, increase its effective AC by 4.

Feats, Racial Traits, & Monster Traits

There are many feats, racial traits, and monster traits that can affect the CR of a monster. The Dungeon Master’s Guide contains a list of features that can be applied to a monster and how that affects their CR calculation.

AggressiveIncrease the monster’s effective per-round damage output by 2.
AmbusherIncrease the monster’s effective attack bonus by 1.
Amorphous— 
Amphibious— 
Angelic WeaponsIncrease the monster’s effective per-round damage output by the amount noted in the trait.
Antimagic Susceptibility — 
Avoidance Increase the monster’s effective AC by 1.
Blind Senses— 
Blood FrenzyIncrease the monster’s effective attack bonus by 4.
Breath WeaponFor the purpose of determining effective damage output, assume the breath weapon hits two targets, and that the target each fails its saving throw.
BruteIncrease the monster’s effective per-round damage by the amount noted in the trait.
Chameleon Skin— 
Change Shape— 
ChargeIncrease the monster’s damage on one attack by the amount noted in the trait.
Charm— 
ConstrictIncrease the monster’s effective AC by 1.
Damage Absorption— 
Damage TransferDouble the monster’s effective hit points. Add one-third of the monster’s hit points to its per-round damage.
Devil Sight— 
DiveIncrease the monster’s damage on one attack by the amount noted in the trait.
Echolocation— 
Elemental BodyIncrease the monster’s effective per-round damage by the amount noted in the trait.
EnlargeIncrease the monster’s effective per-round damage by the amount noted in the trait.
Etherealness— 
False Appearance — 
Fey Ancestry— 
Fiendish BlessingApply the monster’s Charisma modifier to its actual AC.
Flyby— 
Frightful PresenceIncrease the monster’s effective hit points by 25% if the monster is meant to face characters of 10th level or lower.
Grappler— 
Hold Breath— 
Horrifying VisageIncrease the monster’s effective hit points by 25% if the monster is meant to face characters of 10th level or lower.
Illumination— 
Illusory Appearance— 
Immutable Form— 
Incorporeal Movement— 
Innate SpellcastingThe impact that Innate Spellcasting has on a monster’s challenge rating depends on the spells that the monster can cast. Spells that deal more damage than the monster’s normal attack routine and spells that increase the monster’s AC or hit points need to be accounted for when determining the monster’s final challenge rating.  
Inscrutable— 
Invisibility— 
Keen Senses— 
Labyrinthine Recall— 
Leadership— 
Legendary ResistanceEach per-day use of this trait increases the monster’s effective hit points based on the expected challenge rating.
Life Drain— 
Light Sensitivity— 
Magic ResistanceIncrease the monster’s effective AC by 2.
Magic Weapons — 
Martial AdvantageIncrease the monster’s effective per-round damage by the amount gained by this trait.
Mimicry— 
Nimble EscapeIncrease the monster’s effective AC and effective attack bonus by 4 (assuming the monster hides every round).
Otherworldly Perception— 
Pack TacticsIncrease this monster’s effective attack bonus by 1.
ParryIncrease the monster’s effective AC by 1.
PossessionDouble the monster’s effective hit points.
PounceIncrease the monster’s effective damage for 1 round by the amount it deals with the bonus action gained from this trait.
Psychic DefenseApply the monster’s Wisdom modifier to its acual AC if the monster isn’t wearing armor or wielding a shield.
RampageIncrease the monster’s effective per-round damage by 2.
Reactive— 
Read Thoughts— 
Reckless — 
Redirect Attack — 
Reel — 
RegenerationIncrease the monster’s effective hit points by 3 * the number of hit points the monster regenerates each round.
Rejuvenation— 
RelentlessIncrease the monster’s effective hit points based on the expected challenge rating: 1-4, 7 hp; 5-10, 14 hp; 11-16, 21 hp; 17 or higher, 28 hp.
Shadow StealthIncrease the monster’s effective AC by 4.
Shapechanger— 
Siege Monster— 
Slippery— 
SpellcastingThe impact that Spellcasting has on a monster’s challenge rating depends on the spells that the monster can cast. Spells that deal more damage than the monster’s normal attack routine and spells that increase the monster’s AC or hit points need to be accounted for when determining the monster’s final challenge rating.  
Spider Climb— 
Standing Leap — 
Steadfast— 
StenchIncrease the monster’s effective AC by 1.
Sunlight Sensitivity— 
Superior InvisibilityIncrease the monster’s effective AC by 2.
Sure-Footed— 
Surprise AttackIncrease the monster’s effective damage for 1 round by the amount noted in the trait. 
SwallowAssume the monster swallows one creature and deals 2 rounds of acid damage to it.
Teleport— 
Terrain Camouflage— 
Tunneler— 
Turn Resistance— 
Two Heads— 
Undead FortitudeIncrease the monster’s effective hit points based on the expected challenge rating: 1-4, 7 hp; 5-10, 14 hp; 11-16, 21 hp; 17 or higher, 28 hp.
WebIncrease the monster’s effective AC by 1.
Web Sense— 
Web Walker— 
Wounded Fury — 

Any racial traits granted to the monster will be the same as a player character’s block.

CR Calculation Applied in Real-Time

To best illustrate the use of the CR calculation, we will build a monster together! I’ve got to put together a boss monster for my Wizard School campaign, and there are lots of things to consider on that axis because of the unusual nature of the campaign. So, it’s an excellent place to apply all of our theories.

Our party is going to be 1st level Wizards, still, because they’re still in school! So we have to account for the fact they all have 8 hit points and will drop like flies if we give too much damage to this monster. But because they’re all Wizards, if the boss has too little HP, he’ll also drop like a fly.

They also come preloaded with four hirelings that are also 1st level Wizards (because it’s a university, and of course, they have boyfriends and girlfriends like university students often do.)

So we’re building a monster for a party of eight 1st level Wizards. We also need to remember that they don’t have a healer because they’re all Wizards. Their “healing” is killing the enemy, so they can’t take damage.

With these in mind, our expected Defensive CR needs to be in the CR 2-6 range, while our Offensive CR needs to be in the CR 0-1/2 range. Anything that hits harder than a CR 0-1/2 monster will drop them instantly, while anything with defenses lower than a CR 1 monster will pretty much melt immediately.

In this particular situation, the best offense is a good defense. These kids are low-level Wizards. So they come armed with a few really good hits and then sort of just faffing around with cantrips. If we can get through that first round, we put them on the defensive because they’ve got such limited spell slots at level 1.

We’ll give our boss 105 hit points, way more than is expected from a low-level mob. We need him to soak up that early damage, but we don’t want him to be oppressive.

We’ll give him an AC of 14, a little bit higher than low-level, but again, not overpowering. He doesn’t fly naturally, and even if he transforms into a flying creature, he wouldn’t be able to cast spells or make ranged weapon attacks while doing it. He also doesn’t have more than two saving throw proficiencies.

After all calculations and considerations, this gives him a defensive CR of 4, smack dab in the middle of our expected range.

He’s a powerful druid who will be poisoned with a weakening potion that brings him down to the level of our protagonists. So let’s give him a DPR of 3 and an attack bonus of 5 to reflect his former power. This gives him an Offensive CR of 0.625 (about 2/3), which is a little bit higher than we expected.

This mean’s he’s got an aggregated CR of 2 or (4 + 0.625) / 2, rounded down.

We will have to count in that he’s immune to necrotic damage, though. So his final CR is 4 or (2 × 2), rounded down. Whether or not my players will be able to handle that… well… we’ll see. I’ll have to get back to you on that.

CR Calculators

If you don’t want to do all that math by yourself, never fear! There’s plenty of CR calculators that you can use online to calculate the CR of your homebrew monsters!

Brohannes Brahms’s 5e Homebrew CR Calculator

This CR calculator features both a quick calculator and a full-scale calculator accounting for 

/u/ItsADnDMonsterNow’s CR Calculator

This is one of the most comprehensive CR calculators on the web. It accounts for the stats and adds modification for things like Legendary Resistance, feats, and racial traits! It’s very customizable and works great for anyone looking to balance their game meticulously!

Conclusion

Challenge Rating is a very complex subject and a critical part of homebrew campaigns and settings. Whether you calculate your CR manually or use a calculator, getting the hang of the system will improve your DM and player experience! Good luck, travelers!