CR2.0

Challenge Ratings 2.0

Combat is a core part of Dungeons & Dragons 5th Edition. Yet most Dungeon Masters have found 5th Edition's combat-building system to be unreliable at best and misleading at worst.

Some have written that the system is "hopelessly broken" and that relying on it is a "mistake". Others have suggested that combat-building is largely "experience and guesswork" and that combat balance "is an art based on pseudoscience."

Most critics agree that the "action economy" lies at the core of 5th Edition's shortcomings. Yet no combat-building guides thus far have mathematically analyzed how combat works and where 5th Edition goes wrong.

Challenge Ratings 2.0 is the first to do so. Built on a comprehensive mathematical analysis of 5th Edition combat rules, this system provides Dungeon Masters with a simple, flexible, and resilient method for building encounters. From mild skirmishes to overwhelming ordeals, Challenge Ratings 2.0 allows Dungeon Masters to precisely calibrate each encounter to its intended difficulty.

This system is split into two parts: a basic guide and an advanced guide:

The basic guide features a simple, yet powerful method for building balanced encounters.
The advanced guide allows Dungeon Masters to build even more challenging encounters and accounts for unique characteristics like magic items, multiclassing, waves of monsters, and more.

To support my work and access an automated encounter-building tool that uses this system, you can join my Patreon here.

Thank you for playtesting Challenge Ratings 2.0, and happy gaming.

—DragnaCarta

Part I. Basic Guide

Building an Encounter

Step 1. Calculate Party Power

Using the table below, add together the Power of each PC in your party. This is the Party Power.

Level	Power
1	11
2	14
3	18
4	23
5	32

Level	Power
6	35
7	41
8	44
9	49
10	53

Level	Power
11	62
12	68
13	71
14	74
15	82

Level	Power
16	84
17	103
18	119
19	131
20	141

Then, increase the Party Power by the total Power of all summoned monsters and NPC allies. (You can find this information in the table in Step 3.)

Step 2. Determine Encounter Difficulty

Find the intended Encounter Difficulty on the table below.

Encounter Difficulty	Multiplier	Cost
Mild. The PCs will win without a scratch.	0.40	2
Bruising. The PCs will win with minor injuries.	0.60	4
Bloody. The PCs will win with major injuries.	0.75	6
Brutal. The PCs will win, but some may fall unconscious.	0.90	8
Oppressive. The PCs can only win with a little luck or skill.	1.00	10

Then, multiply the Party Power by the encounter's Multiplier. This is the Encounter Power Budget.

Step 3. Choose Monsters

Using the table below, choose a number of monsters whose total Power equals the Encounter Power Budget.

CR	Power
0	1
1/8	5
1/4	10
1/2	16
1	22
2	28
3	37

CR	Power
4	48
5	60
6	65
7	70
8	85
9	85
10	95

CR	Power
11	105
12	115
13	120
14	125
15	130
16	140
17	150

CR	Power
18	160
19	165
20	180
21	200
22	225
23	250
24	275

CR	Power
25	300
26	325
27	350
28	375
29	400
30	425

You're done!

Building an Adventuring Day

Find the Fatigue Level for the adventuring day you'd like to run on the table below. (Resources include hit dice, spell slots, and abilities.)

Total Cost	Fatigue Level
2	Light. The PCs will use few resources.
4	Moderate. The PCs will use some resources.
6	Taxing. The PCs will use a large minority of their resources.
9	Draining. The PCs will use a majority of their resources.
12	Debilitating. The PCs will use nearly all of their resources.
15	Exhausting. The PCs will use all of their resources.

Then, build a number of combat encounters whose total cost (as given in the Cost column in Step 2 of Building an Encounter) is equal to the Total Cost for that Fatigue Level.

Example Encounter

Assume a party of four fourth-level PCs. Each PC has 23 Power, so the Party Power is 92.

The party also includes a CR 1/2 scout, who has 16 Power. The Party Power is now 108.

We want to build a Bloody encounter. A Bloody encounter has a Multiplier of 0.75. We multiply 108, the Party Power, by 0.75 to get 81, the Encounter Power Budget.

We need to choose any number of monsters whose total Power adds up to 81. Let's choose:

One CR 1 bugbear (22 Power each),
Two CR 1/2 hobgoblins (16 Power each), and
Three CR 1/4 goblins (10 Power each).

That brings us to 84 Power, which is almost exactly equal to the Encounter Power Budget. We're done!

Example Adventuring Day

Assume an adventuring day with the following encounters:

A Mild encounter (cost 2),
A Bruising encounter (cost 4), and
A Brutal encounter (cost 8).

The Total Cost is 14, making this a nearly Exhausting day. Assuming they get enough short rests, the PCs will use almost all of their resources, including hit points, hit dice, spell slots, and abilities.

Note: Special Monsters

Be careful when building encounters with monsters whose Power is twice as much as any individual PC's Power. These monsters may deal enough damage to knock out a PC in a single hit, removing them from combat and setting the PCs onto a "death spiral" that may be impossible to recover from.

Additionally, the following monsters are Special CR and should not be used except by an experienced Dungeon Master: shadow, intellect devourer, sea hag, and banshee.

Credits

Challenge Ratings 2.0 is created by DragnaCarta. You can read about the theory behind the system here. (Note that this article is not yet complete.)

Special thanks to: Twi, whose feedback, knowledge, and experience made this project possible; and to Linus, whose mathematical insight cracked the final code.

Additional thanks to: aldman123, Archer, Az, Booyahg, Busdriver, Caesarr, CanadianCruelty, Dragoncrown Games, Edgetaraz, EpicBlundersRPG, Humanfarmerman, James Lorimer, JazzHammy, nolonunez, Paintknight, PunchingPotato, Rolling For What Now?, Schelling, StoryWeaver, Taffer, The Count, and whatisaplunk for feedback and review.

Image credit to: Wizards of the Coast, used under the Fan Content Policy. Dungeon Master's Guide watercolor stains by Jared Ondricek.

Designed with: GMBinder.

Part II. Advanced Guide

Building an Encounter

Step 1. Calculate PC Power

For each PC in the party, complete the following steps.

Step 1a. Determine Primary Level

Find the PC's highest-leveled class. This is their primary class. (If two or more classes are tied, choose one.)

Write down the number of level points (LP) they gain from their primary class using the table below.

Level	LP
1	2
2	7
3	10
4	13
5	18
6	20
7	22

Level	LP
8	23
9	24
10	25
11	28
12	29
13	30
14	30

Level	LP
15	32
16	32
17	35
18	37
19	39
20	40

If the PC has no other classes, skip to Step 1D.

Step 1b. Determine Auxiliary Levels

Determine the PC's auxiliary classes as follows:

If the PC's primary class is a martial class, every other martial or half-caster class that the PC has multiclassed into is an auxiliary class. All other classes are junk classes.
If the PC's primary class is a caster class, every half-caster class that the PC has multiclassed into is an auxiliary class. All other classes are junk classes.
If the PC's primary class is a half-caster class, every other class that the PC has multiclassed into is an auxiliary class.

Increase the PC's total level points by the number of additional level points they gain from each auxiliary class, using the table below.

Level	LP
1	2
2	4
3	6
4	7

Level	LP
5	9
6	10
7	11
8	12

Level	LP
9	14
10	15

Step 1c. Determine Junk Levels

For each level that the PC has taken in a junk class, increase their total Level Points by 1.

Step 1d. Determine Item Bonuses

First, note the AC that the PC would have if they were still using their starting equipment. Add every +1 bonus to AC that the PC has obtained by purchasing or finding new armor. (For example, if the PC began with chain mail, which provides 16 AC, and has since upgraded to plate armor, which provides 18 AC, the PC has received +2 bonuses.)

Then, if the PC has obtained a shield, but their starting equipment does not include a shield, add an additional +2 bonuses.

Increase this number by every magical +1 bonus the PC has to AC, attack rolls, saving throw DCs, and saving throws. (For example, a +1 shield would provide an additional +1 bonus.)

Increase the PC's total level points by the number of additional level points they gain, according to the table below.

Bonuses	LP
1	1
2	1
3	2
4	2

Bonuses	LP
5	3
6	3
7	4
8	4

Bonuses	LP
9	4
10	5
11	5
12	6

Step 1e. Determine Other Bonuses

If the PC will have advantage on all of their attacks, increase their total level points by 2, unless all enemies will also have advantage on attacks against the PC.

If all enemies will have disadvantage to attack the PC, increase the PC's total level points by 3.

Step 1f. Determine Power

Find the PC's Power on the table below, given their total Level Points.

LP	Power
0	11
1	11
2	12
3	13
4	14
5	15
6	16
7	17
8	18
9	20
10	21
11	22

LP	Power
12	24
13	26
14	28
15	30
16	32
17	34
18	36
19	39
20	42
21	45
22	48
23	51

LP	Power
24	55
25	59
26	63
27	67
28	72
29	77
30	83
31	89
32	95
33	102
34	109
35	117

LP	Power
36	125
37	134
38	143
39	154
40	165
41	176
42	189
43	202
44	216
45	232
46	248

Step 2. Calculate Party Power

Add together each PC's Power, including the Power of any monster summons or NPC companions (see Step 4 for this information). The result is the Party Power.

Step 3. Determine Encounter Difficulty

Find the intended Encounter Difficulty on the table below.

Encounter Difficulty	Multiplier	Cost
Mild. The PCs will win without a scratch.	0.40	2
Bruising. The PCs will win with minor injuries.	0.60	4
Bloody. The PCs will win with major injuries.	0.75	6
Brutal. The PCs will win, but some may fall unconscious.	0.90	8
Oppressive. The PCs can only win with a little luck or skill.	1.00	10
Overwhelming. The PCs can only win with a lot of luck or skill.	1.10	13
Crushing. The PCs can only win with an exceptional amount of luck or skill.	1.30	17
Devastating. The PCs can only win under perfect conditions.	1.60	25
Impossible. The PCs cannot win.	2.25	50

Then, multiply the Party Power by the encounter's Multiplier. This is the Encounter Power Budget.

Step 4. Choose Monsters

First, determine which tier of play your PCs are in:

Level	Tier of Play
1-4	Tier 1
5-10	Tier 2

Level	Tier of Play
11-16	Tier 3
17-20	Tier 4

Using the table to the right, choose a number of monsters whose total Power equals the Encounter Power Budget, given the PCs' tier of play.

However, if a monster has resistance or immunity to all nonmagical weapon damage, decrease its CR by 2 if all PCs can consistently deal magical damage. If a monster can kill or KO one or more PCs on the first turn of combat, increase its CR by 4.

Note that the following monsters are Special CR and should not be used except by an experienced Dungeon Master: shadow, intellect devourer, sea hag, and banshee.

Why Does Power Change?

Why does a monster's Power vary with the PCs' level? If a PC has a comparatively low AC and attack bonus, the monster hits more often (increasing its effective damage) and is hit less often (increasing its effective HP). The inverse is also true!

Monster Power by Challenge Rating

CR	Tier 1	Tier 2	Tier 3	Tier 4
0	1	1	0	0
1/8	4	3	3	2
1/4	10	6	5	4
1/2	16	12	7	5
1	22	17	15	8
2	28	23	19	14
3	37	30	25	19
4	48	38	32	24
5	70	60	45	40
6	80	65	50	40
7	90	70	55	45
8	105	85	70	55
9	110	85	70	55
10	115	95	75	60
11	140	130	105	85
12	150	140	115	90
13	160	150	120	95
14	165	155	125	100
15	175	165	130	105
16	185	175	140	110
17	250	200	190	150
18	260	210	200	160
19	280	220	210	170
20	300	240	230	180
21	400	350	275	250
22	450	375	300	275
23	500	425	325	325
24	550	450	375	350
25	600	500	400	375
26	650	525	425	400
27	725	600	475	450
28	775	625	500	475
29	775	650	525	475
30	850	725	575	525

Building an Adventuring Day

Find the Fatigue Level for the adventuring day you'd like to run on the table below. (Resources include hit dice, spell slots, and abilities.) Note down its Total Cost.

Total Cost	Fatigue Level
2	Light. The PCs will use few resources.
4	Moderate. The PCs will use some resources.
6	Taxing. The PCs will use a large minority of their resources.
9	Draining. The PCs will use a majority of their resources.
12	Debilitating. The PCs will use nearly all of their resources.
15	Exhausting. The PCs will use all of their resources.

Then, for each consumable magic item or fully-charged magical item that your PCs can use to deal damage, recover hit points, or inflict debilitating conditions, find the item's Resource Modifier on the table below and divide it by the number of PCs in the party. Add the result to the Total Cost. (For a consumable magic item, use the number in parentheses instead.)

Party Level	Uncommon	Rare	Very Rare	Legendary
1-4	15 (2)	120 (17)	360 (51)	600 (85)
5-10	2 (0)	15 (2)	45 (6)	75 (10)
11-16	1 (0)	5 (0)	15 (2)	25 (3)
17-20	0 (0)	3 (0)	9 (1)	15 (2)

Then, build a number of combat encounters whose total cost (as given in the Cost column in Step 2 of Building an Encounter) is equal to the Total Cost for that Fatigue Level.

In order to ensure that short-rest classes have as many resources to spend as long-rest classes, aim to ensure that your party takes an average of two short rests per day.

Example Encounter

Assume the following fourth-level party:

One 4th-level wizard with a wand of magic missile.
One 4th-level cleric with plate armor and a +2 holy symbol.
One Paladin 2/Sorcerer 2 wielding a +1 shield.
One Fighter 2/Rogue 1/Wizard 1.
One CR 1/2 scout NPC ally.

According to Step 1A of Building An Encounter, each PC gains the following level points from their primary class:

Wizard: 13 LP (Level 4)
Cleric: 13 LP (Level 4)
Paladin: 7 LP (Level 2)
Fighter: 7 LP (Level 2)

According to Step 1B, each PC gains the following number of LP from auxiliary levels:

Wizard: +0 LP (Total: 13 LP)
Cleric: +0 LP (Total: 13 LP)
Paladin: +4 LP (Total: 11 LP)
Fighter: +2 LP (Total: 9 LP)

According to Step 1C, each PC gains the following number of LP from junk levels:

Wizard: +0 LP (Total: 13 LP)
Cleric: +0 LP (Total: 13 LP)
Paladin: +0 LP (Total: 11 LP)
Fighter: +1 LP (Total: 10 LP)

According to Step 1D, assuming the cleric began with chain mail, each PC gains the following number of LP from item bonuses:

Wizard: 0 Bonuses → +0 LP (Total: 13 LP)
Cleric: 4 Bonuses → +2 LP (Total: 15 LP)
Paladin: 1 Bonus → +1 LP (Total: 12 LP)
Fighter: 0 Bonuses → +0 LP (Total: 10 LP)

The PCs have no other bonuses, so we skip Step 1E. According to Step 1F, each PC has the following amount of Power:

Wizard: 26 Power
Cleric: 30 Power
Paladin: 24 Power
Fighter: 21 Power

According to the Monster Power chart in Step 4, the CR 1/2 scout NPC ally has 16 Power in Tier 1. Altogether, the Party Power is 117.

Let's build a Bloody encounter: The PCs will be notably injured, but will win the encounter. Accordingly, we multiply the Party Power by 0.75, the Difficulty for a Bloody encounter, to get the Encounter Power Budget: 88.

Now, we need to choose any number of monsters whose total Tier 1 Power adds up to 88. Let's choose:

One CR 1 bugbear (22 power each) ,
Two CR 1/2 hobgoblins (16 power each) ,
Three CR 1/4 goblins (10 power each) , and
Four CR 0 rats (1 power each) .

This brings us to 88 monster power exactly.

Example Adventuring Day

Let's assume that this is the only encounter our PCs will face today. The Total Cost for today starts at 6, which is the sum of all Encounter Costs that the PCs will face.

Now, because our wizard has a fully-charged magic item that can deal damage or inflict debilitating conditions (a wand of magic missile), we need to subtract the item's Resource Modifier from the Total Difficulty.

A wand of magic missile is an Uncommon charged magic item. As such, its modifier for a party of level 4 is equal to 15 divided by the number of characters in the party (5).

The modifier is therefore equal to 3, which we then subtract from the Total Cost (6) for a final result of 3 (Light).

Note: Waves of Monsters

For an encounter with multiple consecutive waves of enemies (or a single enemy with multiple phases), build each wave as a separate encounter. Then, add each wave's cost together to determine the cost (and therefore the difficulty) of the overall encounter.

Note: Creature Agency

Creature Power is only one component to evaluating an encounter's difficulty. Monsters and PCs with access to spells and spell-like effects, such as teleportation or flight, can reach even greater heights with the right tactics and strategy. Look out for a companion guide on "Creature Agency" to be released soon on the Dragna's Den Substack.

Changelog

Aug. 3, 2022. Updated Monster Power by Challenge Rating table in the Advanced Guide to account for low-CR monster power decay. Revised Step 1. Calculate PC Power in the Advanced Guide to account for favorable multiclass combinations.
Aug. 6, 2022. Updated Step 1B. Determine Auxiliary Levels level points table in the Advanced Guide to key off of proper multiclass benchmarks. Updated Step 1D. Determine Item Bonuses Bonuses table in the Advanced Guide to account for new Level Point scaling. Simplified Step 1C. Determine Boost Ratio in the Advanced Guide.
Aug. 8, 2022. Simplified Step 1B. Determine Auxiliary Levels in the Advanced Guide. Updated values for Monster Power by Challenge Rating, Step 1A. Determine Primary Level, and Step 1E. Determine Power tables in the Advanced Guide.
Aug. 9, 2022. Fixed table in Step 1B. Determine Auxiliary Levels to indicate aggregate Level Points, rather than marginal Level Points. Changed heading of Step 1C. Determine Junk Levels. Shrunk table in Step 1E. Determine Power to reflect current maximum Level Point value.
Aug. 10, 2022. Added Step 1e. Determine Other Bonuses to reflect level point adjustments for advantage and disadvantage.
Aug. 12, 2022. Updated Example Encounter in the Advanced Guide to reflect updated mathematics. Cleaned up Bonuses table in Step 1D. Determine Item Bonuses in the Advanced Guide. Removed A Point of Reference text box in the Advanced Guide.
Nov. 17, 2022. Updated Example Encounter in the Basic Guide to reflect updated mathematics.