Thoughts on 5e encounter building

September 17, 2014 at 10:00 am
filed under Roleplaying

The way encounter building works in 5e is similar to 4e. However it departs from the role-based allocation, and from the one-monster-per-character-based system.

How to build an encounter w/ examples

At a high level, the inputs are: XP for each monster and quantity of monster to calculate actual difficulty, and then level of players and number of players for expected difficulty.

Here’s a quick example.

We have four PCs, all level 1 and I want to use goblins. How many can they take? One goblin is 50 XP. Two goblins add up to 150 XP, just shy of medium difficulty for this party. Three goblins add up to 300 XP, which is hard difficulty.

How about kobolds instead? They’re 25 XP so four of them adds up to 200 XP. For 10 XP, you need 9 to get to 200 XP.

You can mix and match. Two 10 XP monsters and two 50 XP monsters adds up to 240 XP.

Challenge rating

I don’t really get CRs below 1. My hunch is that they’re not meant to aggregate as neatly as they were intended to in 3E.

A kobold is CR 1/8, but 4 – 6 kobolds are the sweet spot. 8 is beyond deadly for four level 1 characters, and deadly for five level 1 characters.

The gist of it is that x1, x1.5, and x2 multipliers for 1, 2, and 3 – 6 monsters makes a big difference.

That said, it’s amazing what a difference it makes to get to level 2. 8 kobolds or 4 goblins are comfortably between medium and hard, so the fractional CRs add up more nicely.

How does difficulty scale?

OK, so for the “perceived” difficulty table, some things stood out to me. Obviously the values for easy, medium, hard, and deadly go up with level. So when do deadly encounters become easy?

A deadly encounter for a level 1 party is easy around level 4. A deadly encounter for level 5 isn’t easy until 13. The last deadly-to-easy encounter is 10 to 20.

There’s a big inflection point around level 5, presumably to reflect the fact that many (all?) classes get a big boost: Extra Attack, Uncanny Dodge, level 3 spells, etc.

Level 17 seems like the last point you get to feel really superior to everyone else. You’ll never have an encounter go from “deadly” to anything less than “hard.” Stupid dragons, am I right?


That’s all for now, blog!

  • mbeacom

    I haven’t looked closely at encounter building math. What am I missing with this below?

    “One goblin is 50 XP. Two goblins add up to 150 XP, just shy of medium difficulty for this party. Three goblins add up to 300 XP”

  • Matthew

    I had a longer explanation but then I thought I was retreading too much territory from the DMG. Oh well. :)

    The piece you’re probably missing is the multiplier based on the number of monsters your encounter has. It’s 1x for one monster, 1.5x for two, and 2x for 3 – 6, and so on. I presume this is to reflect the potentially sharp difficulty curve for adding more monsters.

    From the “XP per adventuring day” numbers, it can take as little as one day to get to level 1. Then level 2 and 3 characters, while still “low level,” dramatically increase in potency as their archetypes begin to come online.

  • mbeacom

    Ok, I figured it was something like that based on the mention of multipliers in your article. When you say in the “DMG” I’m assuming you mean the free DM PDF. I’m running published material now, but can’t wait to start building more creative encounters using these guidelines. Thanks again!

  • Matthew

    No problem! Yes, I meant the DMG basic rules.

    In case you haven’t checked it out, the DMG basic rules PDF has a substantial list of monsters *and* NPCs, as well. IMHO it’s enough to put together a surprising variety of encounters.

  • mbeacom

    Yes, thank you! I have the PDF and have looked at the monsters but hadn’t really read the encounter building rules yet since I’m mostly just tweaking the encounters in Dragonspear Castle and soon Hoard of the DRagon Queen. I love that they have rules for large groups. That will come in handy. We almost never did that with anything but minions in 4E and that got very gamey for my tastes. I eventually started creating 2 hit minion varieties which was fun. So far, the monsters look good, but are not quite as deadly as I would like. I really like the Dominate on the playtest vampire but that’s gone now. We had a lot of fun with that one.

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