How Exactly Do I Balance Combat Encounters In D&D With The Rules From The DMG?

Question

So, I have a quick question about the encounter balancing. Now, I know HOW to do it, and I have done it the same way all the way through CoS...but I'm starting to think I might be wrong here. When it says to round it down to an appropriate XP threshold for the party, am I supposed to take enemies out until it's close or am I supposed to just consider it under a certain type? Like if it's 300 XP and I'm supposed to round down to 200, does that mean I take enemies out until then or just consider the 300 under the 200 bracket?

Look, I know it's an absolutely stupid question and you are probably wondering how I managed to get through a whole campaign like this...but in honest I got REALLY lucky because the group size I had for CoS was a little on the bigger side, so it didn't seem to matter.

Any and all help is greatly appreciated!

Edit: To everyone that answered and confirmed my initial instinct to be right, I very much appreciate it and I wish I could tag all of you in one response and thank you all collectively. None the less, thank you!

Answer 1

The CR encounter system is not an exact science

I think, overall you are worrying too much about getting the exact point values calculated here. In our group's experience, a typical party can endure much more than the XP value of a deadly encounter, and there is wide disparity about how dangerous a monster of a given CR and XP value actually is.

You can even see it from the rules themselves, which provide the same x2 XP multiplier for 3 monsters and for 6 monsters -- that is twice as many monsters, which are able to deal twice as much damage, have twice as much hp, etc., for exactly the same XP value.

That being said, there is no rounding down involved. What point 5. of the process says is:

5. Compare XP. Compare the monsters' adjusted XP value to the party's XP thresholds. The threshold that equals the adjusted XP value determines the encounter's difficulty. If there's no match, use the closest threshold that is lower than the adjusted XP value. For example, an encounter with one bugbear and three hobgoblins has an adjusted XP value of 1,000, making it a hard encounter for a party of three 3rd-level characters and one 2nd-level character (which has a hard encounter threshold of 825 XP and a deadly encounter threshold of 1,400 XP).

That pretty much explains it. For example, you have three 3rd level characters that have a value of 225 XP for hard, 400 XP for deadly, and one 2nd level who has 150 for hard, 200 for deadly. Summing them all up you get 3x225+1x150= 825 for hard, and 3x400+1x200=1,400 for deadly.

The monster has an XP value of 1,000, which is above the threshold for hard for this party, and below the threshold for deadly. In that case, the encounter is considered to be hard. You need to clear the threshold for the category to have it counted as an encounter of that category. That means there is a range of XP values for this party that all count as hard, from 825 XP to 1399 XP.

This is unavoidable and intended -- there need to be ranges for each category, because there are many different XP values for encounters, and if you just have four categories, you need to group those XP values into ranges for them. You do not need to remove any enemies to get close to the lower end of the XP range.

Answer 2

Short answer: You don't round anything. Instead, the difficulty of the encounter is given by:

1. Calculate the number-adjusted XP for the encounter
2. Calculate the thresholds (look up thresholds for each character's level, add similar thresholds together).
3. The difficulty is given by the largest threshold that is below the adjusted encounter XP.

Example

I have 4 level 3 characters. The encounter consists of 1 CR 2 ( 450 XP) and 5 CR 1/8 (25 XP).

1. Base XP = 450 + 5*25 = 575 XP. Adjusted for size: multiplier is x2 for 6 creatures, resulting in an adjusted XP of 1150 aXP.
2. Thresholds for 4x level 3s are:

• Easy: 4x75 = 300 aXP
• Medium: 4x150 = 600 aXP
• Hard: 4x225 = 900 aXP
• Deadly: 4x400 = 1600 aXP

3. Since Hard (900) < 1150 < Deadly (1600), the rule says to use the lower bound. Thus, the encounter is Hard.

Answer 3

The section you're looking at is talking about determining whether to classify an encounter as Easy, Medium, Hard, or Deadly.

"Compare the monsters' adjusted XP value to the party's XP thresholds. The threshold that equals the adjusted XP value determines the encounter’s difficulty. If there’s no match, use the closest thresh­old that is lower than the adjusted XP value."

In other words, if your encounter XP total is between two entries on the list, then you use the easier of the two as the difficulty of the encounter.

So as an example, if your party of 5 is at 1st level, the XP limits say
Easy: 125
Medium: 250
Hard: 375

If your encounter is worth 275 XP, then it falls between Medium and Hard, and the rule says you count it as a Medium difficulty encounter in that case.

You don't need to remove monsters from the fight to hit your target number or anything -- just understand that this effectively makes the Medium difficulty cover any fight from 250 XP to 374 XP.

Now that said, if you come up with a 370 XP encounter, you should be noticing that you're really high for a Medium difficulty encounter, and you might want to either tone it down just a bit, or add one more enemy and make it a Hard encounter.