5e: How Does CR Work — Make a Skill Check

5e: How Does CR Work


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Your friends have asked you to run D&D for them. They’ve all made 1st level player characters (PCs), and you have a great idea for a vampire as a villain. You look up the vampire stat block in the Monster Manual, and yeah, the PCs wouldn’t last a second. How did you come to this conclusion? You looked at the challenge rating (CR)—here’s what it means:

CR is a rating system in 5e that estimates the threat level of enemies. A party of four adventurers can defeat an enemy of CR equal to their level without suffering any significant trouble. CR is also used to track XP progression and leveling up.

Challenge rating is a system with many benefits and flaws. Since an unbalanced game of D&D is no fun, let’s dive into how this all works so that we can understand how to make a tense, high-stakes game without taking away all chance of success from our players.

How does Challenge Rating Work?

Although challenge rating ranks enemy NPCs and monsters by threat level, it is not equivalent to character level. If a brown bear (CR 1) fought a 1st level wizard, it would be far from a fair fight. That wizard would quickly become bear food.

A creature with a CR 1 means that it is a suitable encounter for a party of four 1st level characters. 

At a glance, it would seem that CR is then equal to four times character level. However, it quickly becomes more complicated when considering multiple monsters, player abilities & party composition, and special monster abilities.

In the above example, a vampire is a CR 12 monster, making it suitable for a 12th level party, and would eviscerate a 1st level party. If you want to start adjusting monsters to be suitable for your party, that’s a whole other topic, but you can find a great resource for how to do that here.

Using Challenge Rating and XP

Every challenge rating from 1 to 30 has a designated amount of experience points (XP). This XP is awarded to players who defeat the given monster.

Some creatures pose such a low threat that they are designated CR 0. Those with any kind of attack are worth 10 XP, and those without an attack are worth 0 XP.

A creature’s CR also determines its proficiency bonus. The first time you look through the Monster Manual, you might think that a monster has a +11 to hit because it’s a tough monster. 

That may be true, but that +11 still comes from the creature’s ability score—for example, strength for a melee attack—and their proficiency bonus. This is the same as how players determine their attack bonuses.

Below is the full list of Challenge Ratings you can find in the Monster Manual, Volo’s Guide to Monsters, Mordenkainen’s Tome of Foes, and every other D&D book with a stat block.

ChallengeXPProficiency BonusChallengeXPProficiency Bonus
00 or 10+21411,500+5
1/825+21513,000+5
1/450+21615,000+5
1/2100+21718,000+6
1200+21820,000+6
2450+21922,000+6
3700+22025,000+6
41,100+22133,000+7
51,800+32241,000+7
62,300+32350,000+7
72,900+32462,000+7
83,900+32575,000+8
95,000+42690,000+8
105,900+427105,000+8
117,200+428120,000+8
128,400+429135,000+9
1310,000+530155,000+9

If a party of four players defeats a monster of CR 3, the party receives 700 XP. Unless specified otherwise by the DM, each member of the party receives an equal share of 175 XP each.

As players gain XP, they level up, gaining more abilities and growing in power. This, in turn, allows them to take on monsters of higher CR.

How to Use CR to Balance Encounters

One of the most important things in all games is balance. If an encounter is too hard, the players can feel like they’re helpless. If it’s too easy, the party can get bored.

The process found in the Dungeon Master’s Guide (DMG, pg. 82) for using CR to build an encounter is:

  1. Determine XP Thresholds
  2. Determine the Party’s XP Threshold
  3. Total the Monsters’ XP
  4. Modify Total XP for Multiple Monsters

Understanding how this all works helps you to continue to make interesting encounters ahead of time and on the fly. You can also start to homebrew your own monsters in custom stat blocks

But you don’t have to do all the math yourself. Here is an online encounter calculator that is an absolute lifesaver.

Determine XP Thresholds

A PC’s XP threshold is the minimum XP worth of enemies it can take on for a given encounter difficulty. 

For example, a 3rd level character’s XP threshold for a medium encounter is 150 XP. This means that anything between 150 XP and the next difficulty threshold 225 XP will be in the medium difficulty category. As soon as it reaches 225 XP, it is categorized as hard.

Encounter Difficulty

Character LevelEasyMediumHardDeadly
1st255075100
2nd50100150200
3rd75150225400
4th125250375500
5th2505007501,100
6th3006009001,400
7th3507501,1001,700
8th4509001,4002,100
9th5501,1001,6002,400
10th6001,2001,9002,800
11th8001,6002,4003,600
12th1,0002,0003,0004,500
13th1,1002,2003,4005,100
14th1,2502,5003,8005,700
15th1,4002,8004,3006,400
16th1,6003,2004,8007,200
17th2,0003,9005,9008,800
18th2,1004,2006,3009,500
19th2,4004,9007,30010,900
20th2,8005,7008,50012,700

Determine the Party’s XP Threshold

After determining the party members’ individual thresholds, simply add them together to determine the total XP threshold for each encounter difficulty.

For example, three 2nd level characters would need a total XP of 450 for a difficult battle. The 450 XP can be from one creature, like an Azer, or spread across several enemies, but more enemies mo problems (see next section).

You should now have an XP threshold for your party for easy, medium, hard, and deadly encounters. 

Total the Monsters XP

Start planning what enemies your players will be fighting. The CR of the monster you are using will tell you how much XP they are worth. 

Modify Total XP for Multiple Monsters

Most encounters will likely be more than a fight with a single enemy. If your party is facing off against multiple foes, multiply the total XP for the monsters according to the below table.

Encounter Multipliers

Number of MonstersMultiplierNumber of MonstersMultiplier
1x17-10x2.5
2x1.511-14x3
3-6x215 or morex4

This is an incredibly important step. Let’s look at why.

The first encounter my party fought was from the starting adventure Lost Mines of Phandelver against four goblins.

All at first level, the four-person party’s XP threshold for each difficulty was 100 XP (easy), 200 XP (medium), 300 XP (hard), and 400 XP (deadly). Goblins are CR 1/4: 50 XP.

The four goblins’ total XP was 200 XP—a medium encounter. According to our definition of CR, it seems accurate that if four 1st level adventurers can take on a CR 1 creature; they should be able to take on four CR 1/4 creatures, shouldn’t they?.

Imagine my surprise when one of the players was knocked unconscious, and the goblins were barreling full-speed toward a total party kill (TPK).

A few bad rolls when you’re 1st level can mean disaster, but the party was rolling pretty well. What happened?

Fighting one CR 1 monster is much easier than fighting four CR 1/4 monsters because of 5e’s action economy. For example, a brown bear has two attacks per round. A four-person party has at least four actions. One creature can also be avoided, restrained, or otherwise incapacitated. 

Four goblins have four attacks per round. If one of the adventurers falls unconscious, the goblins now outnumber the heroes, leading to a death spiral and potential TPK. As long as the two sides are of similar power levels, the side with the most actions wins.

When determining the difficulty of an encounter using CR, multiply the monsters’ total XP by the appropriate multiplier for the number of monsters. 

If your party size differs, adjust accordingly. Parties larger than five will have an easier time and should use the multiplier one step down. Parties fewer than three should use the multiplier one step up.

In the above case, we see that the fight with four goblins has a x2 multiplier, and the difficulty, measured in XP, is 400 XP: a deadly encounter. Note that the party won’t receive 400 XP for killing the goblins; it’s just for determining difficulty.

Running a deadly encounter is fine, but it is important to know what you are challenging your players with. It does raise a good question…

How Difficult Should Encounters Be?

How much do you want to challenge your players? As the Dungeon Master (DM), you get to decide.

The DMG assumes that a party of adventurers will be taking on 6-8 medium to hard encounters in one day, with two short rests taking place.

In reality, most DMs don’t do this. In this tweet, Matt Colville polled DMs on this, and 59% said their players face only 1-2 encounters a day, 36% claimed 3-4, and only 4% said their players face 5-6.

How many encounters will your players face before they are able to take a long rest and regain their abilities? If it’s fewer than the assumed 6, you can afford to make them harder.

Also, consider what sort of tone you want to set for your campaign.

Do you want your world to be highly lethal, needing players to be strategic and lucky to survive through the early levels? Do you want your players to feel like powerful heroes tearing through enemies? Both can be fun if the players know what to expect.

In general, make encounters harder than you think. There’s a lot that the CR process does not account for:

  • Magic items: Any magic items your players acquire over their adventures usually make them more powerful adventurers capable of harder challenges.
  • Player Optimisation: Do your players min-max everything? Do they always try to play strategic and optimal? Are they experienced wargamers, or are they new to the game? 
  • The Environment: In addition to enemies, players have to worry about the environment around them. Are they fighting on the edge of a cliff? Will they be able to get cover from their enemies? If the environment is a challenge itself, you can lower the challenge of the enemies to accommodate.
  • Party Composition: 5e doesn’t require a party to be composed of particular classes. If you want a party of all wizards, great! But as a DM, you need to consider this when building your encounters. It can be essential to understand something as simple as what forms of healing the party has access to.
  • Preparation: Do your players know what they’re about to fight? Do they have time to prepare spells just for this encounter? The more knowledge your players have, the easier the encounter will be.
  • Special Abilities: We’ll cover this more in the next section, but it is important to consider what the special abilities of the monsters are and how they will affect the party.

If you’ve never run a combat encounter before, start by running a medium difficulty encounter. Get used to tracking monsters’ HP, controlling the movement of multiple creatures, and responding to your players. Then, turn up the difficulty for next time. 

Looking to challange your players?

Puzzles and Riddles can be tricky! Too easy and they’re pointless; Too hard and it’s pure frustration. What is a DM to do?

Well, our friends over at Dungeon Vault have an assortment of puzzles, riddles, and tokens to enhance your gaming experience. They even have a murder mystery and a political intrigue system!

For easy-to-use resources for any D&D game, check out the selections at Dungeon Vault!

Monsters with Inaccurate CR

There are some monsters in D&D whose CR rating makes you scratch your head in confusion because they’re severely overpowered.

Here are a few problem cases, but when building an encounter, always look at the enemy’s special abilities. Not the bite and claw attack—Look at the other special properties of the monster that sets it apart. Then think about how that would affect your party. 

The following monsters’ imbalances remain a problem for a very long time. My recommendation: avoid using them if you’re just starting out.

Rust Monsters

Rust monsters are CR 1/2, making them a supposed low-level threat. However, they have an ability called Rust Metal.

Any non-magical metal weapon that hits the rust monster corrodes, taking a permanent and cumulative -1 to damage. If that reaches -5, the weapon is destroyed. It can also use its action to inflict this effect on weapons and on metal armor and shields.

Given its CR, this is a monster that could be encountered within the first few levels. However, if the party is in the middle of a dungeon and their swords get destroyed, what do they do now?

Rust monsters are fun to use, but keep in mind what they can do, especially if the party is melee-heavy. Make sure to give your players ways of getting new weapons soon after that encounter and maybe some extra gold so that they can pay for them—since gold & silver can’t rust, there could be a neat little pile awaiting the party.

Intellect Devourers

These walking brain monsters are only CR 2, but they can drop a creature to 0 Intelligence in one hit. That’s right, one hit. 

In addition to this, it can target an incapacitated creature and magically consume their brain!

Recovering from being reduced to 0 Intelligence requires at least Greater Restoration: a 5th level spell. Recovering from having your brain consumed? You’re going to need access to at least a 7th level spell of Resurrection or similar. More on those spells here and here.

Shadows, Specters, and Wights

There are a few creatures who have draining abilities in D&D. At higher levels, this is something that’s a little easier to weather.

Shadows are CR ½, but their Strength Drain ability allows them to reduce the target’s Strength score by 1d4. If it is reduced to 0, the target dies. A character with Strength as their dump stat can be fully killed in only a couple of hits.

Despite Specters and Wights only being CR 1 and CR 3, respectively, their Life Drain ability prevents the use of healing because the damage that they do reduces the target’s HP maximum. Similarly, if this is reduced to 0, the target dies outright.

These abilities are cool and thematically appropriate for the monsters. However, if they’re not taken into consideration when designing an encounter, it could mean disaster.

Rakshasas

Rakshasas are pipe-smoking, shape-shifting, backwards-hand-having fiends with powerful innate magic. They are CR 13, so a party won’t encounter them until higher levels.

However, they have an innate Limited Magic Immunity that makes them immune to spells of 6th level or lower. Fighting one of these with a spellcaster-heavy party is going to be much more difficult than a CR-similar encounter for the same level.

Play as Rocky Balboa

Take hits on the chin and uses the pain to fuel stronger attacks. Soak up damage and keep on swinging. Spend Moxie for special abilities and regain moxie through the fray.

Subclasses allow you to play as a wrestler, a street-hardened Detective, an underground boxer, a luchador, or even have a dog companion!

This build makes fighters like Tifa (FF7), Little Mac (Punch-Out!!/Smash Bros.), Luke Cage, or even the lead from Nacho Libre. The choice is yours!

Check out the Pugilist, a custom class made by Benjamin Huffman.

Summary

Challenge rating ranks all the enemies and monsters in D&D to assess threat level and XP value for the adventuring party.

  • A party of four adventurers can fight an enemy of CR equal to the party’s level without suffering any significant losses.
  • Because of 5e’s action economy, a greater number of lower CR monsters is a bigger threat than one monster of equivalent CR.
  • CR can be used to build balanced encounters by:
    1. Determining each player’s XP threshold: Encounters difficulty is based on the amount of XP per player. See the chart above.
    2. Determining the party’s XP threshold: add each party member’s XP threshold together.
    3. Totaling the Monsters’ XP
    4. Modifying Total XP for Multiple Monsters: use the modifiers in the table above for determining difficulty.
  • When giving XP to players, don’t use the multiplied total for multiple monsters.
  • CR doesn’t account for everything. Use it as a baseline for your encounters and adjust according to:
    • Magic items
    • Player Optimisation (e.g., min-maxing)
    • The Environment
    • Party Composition
    • Preparedness of the Party
    • Special Abilities

Challenge Ratings are a useful tool in D&D to build fun, challenging encounters for your players. It’s far from perfect, and you will need to adjust according to your party and the game that you’re running.

If things go wrong, don’t take it too hard. Everything is a learning experience!

Ethan

Ethan is a storyteller, GM, and all-around nerd. He spends his time introducing all of his friends to D&D and creating hard magic systems for upcoming novels.

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