10
\$\begingroup\$

I have played some games of D&D and when it comes to groups of enemies, I'm always asking myself "Does this encounter have a good CR for my group? Is it too strong/weak?".

I might have missed the point in the DMG or the MM where the formula to calculate the CR of a group of enemies is given, but since I couldn't find it, I came here to ask if someone knows it.

\$\endgroup\$
7

2 Answers 2

17
\$\begingroup\$

The answer to this is slightly more complicated than I think most would like. There's no easy way to calculate the total CR of an encounter; CR is one factor used in assessing Encounter Difficulty. (Which appears to be your actual question, assessing encounter difficulty). You (1) use CR to calculate the XP value of the encounter, and (2) then compare that to the Encounter Difficulty table (after applying the formula for multiple creatures) and (3) then compare that to the chart given on page 82 of the DMG.

The calculation process

Let's use level 4 characters

  1. A level 4 character provides the XP thresholds of: 125 for easy, 250 for medium, 375 for hard, and 500 for deadly (this chart is on pg 82 of the DMG).

  2. A party of 4 level 4's have the values of: 500, 1000, 1500, 2000 for easy, medium, hard, and deadly respectively. Now, you might be thinking "Oh, that's not too bad!" but we're not done here.

  3. If you have 1 monster all you have to do is compare it's XP value to your formula and you're good to go! Like a CR 5 Bulette (1800 xp) is a Hard encounter for your PCs.

  4. If you add more monsters page 82 provides more help in the form of another table.

    • If you have 2 monsters you multiply their total XP by 1.5, if there's 3-6 you multiply by 2, and this continues.

Example Multi-Monster Encounter for that party.

If you have 3 CR 2 Ettercaps (450 XP each, modified to 2700 by formula) confront the party, it's a deadly (Probably much more than deadly) encounter for that party.

That same encounter for 4 5th level adventurers

From the XP Threshold table, a 5th level character's values are:
Simple: 250, Medium: 500, Hard: 750, Deadly: 1,100. (1000, 2000, 3000, 4400 for a party of four)
The same 3 Ettercap encounter is between Medium and Hard for the higher level party. (DMG suggests rounding down so it's a "Medium" encounter in this situation.

Too much math?

I agree! There's a website called Kobold Fight Club that will do all this math for you! All you need to do is input party size and level and select your monsters and you can see how difficult (and how much XP they'll get!) for an encounter

\$\endgroup\$
4
  • 1
    \$\begingroup\$ I did a bit of formatting, and added the examples, to better illustrate your points. (This is the kind of answer I had in mind to offer, thanks for saving me the work!) +1 \$\endgroup\$ Dec 23, 2019 at 16:42
  • \$\begingroup\$ It’s worth pointing out that the DMG recommends not pitting the party against monsters with a CR higher than the party’s level. So a CR 5 bulette against a level 4 party might be more deadly than the XP table implies. \$\endgroup\$
    – ktt4d
    Dec 24, 2019 at 4:03
  • \$\begingroup\$ Could you make the reference book and page more visible? It's buried in sentences and barely visible at a quick glance, to the point where I initially wanted to ask you to add those references before reading it entirely and finding the answer. \$\endgroup\$ Dec 24, 2019 at 13:15
  • \$\begingroup\$ @ktt4d in my experience with a 4v1 the party can win an encounter that was much beyond deadly due to the action economy. Especially if you have very tactical players using haste and other buffs optimally. \$\endgroup\$ Dec 24, 2019 at 14:15
3
\$\begingroup\$

The rules for balancing a combat encounter are found in chapter 13 of the basic rules or chapter 3 of the Dungeon Masters Guide.

An alternative format, but using the same math underneath, is found in chapter 2 of Xanathar's Guide to Everything. The play test version of this alternative format can be found in the Encounter Building Unearthed Arcana.

Various online calculators can also be used, including one from dndbeyond.

\$\endgroup\$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .