How many enemies will challenge my party of four 1st-level characters, but not result in certain death?

Question

I was asked to DM for a one-shot with people wanting to try and learn the game. I have created a not-too-complicated world in which they can run around and interact with its inhabitants.

The problem I face is the number and strength of foes that can be encountered. How do I prepare a challenge to the players while they learn the game? I want them to be a little afraid while still having chance of saving the town/rescuing the princess or prince/find the treasure.

• These are completely new players, there will be 4 of them.
• They will play level 1 characters: a paladin, barbarian, rogue and sorcerer.
• I play a separate campaign with other people but have never been a DM before.
• We expect to play for about 4 hours - unless everyone is having fun and wants to continue, of course.
• Based on decisions, the enemies will be either goblins or pirates. I tend to keep these enemies around the same level.
• I would like to introduce one "boss" in the shape of a goblin chief/pirate captain.

How many enemies, based on the information above, would make for a balanced and fun game? I don't really want everyone to bite the dust on their first game ever, but also want to keep it interesting at the same time.

Answer 1

Use the Tables provided in the Dungeon Master's Guide

Chapter 3 of the Dungeon Master's Guide, in the section Creating Encounters, specifies some general purpose rules for building encounters. I highly recommend you read the whole chapter, since the advice is applicable to almost any normal scenario, but I'll copy the important bits for your benefit here.

To start with, the DMG offers a table of XP thesholds for encounter difficulty. Since you're dealing with Level 1 characters, I've copied the first row here:

Level	Easy	Medium	Hard	Deadly
1	25	50	75	100

What this tells you is that for the average party of 4 1st level characters, an easy encounter contains creatures worth 25xp per party member, or for 4 characters, 100xp overall. 200xp for a medium encounter, 300xp for hard, 400xp for deadly.

The XP values of the creatures you use can be pulled from their individual Statblocks. For example, a CR1 creature is worth 200xp, meaning a single CR1 creature should pose a "medium" difficulty for the average party of 1st level characters. CR1 creatures tend to vary in overall stats by a great deal (some have as many as 60 hitpoints while others only have up to 20), so you'll need to tune which creatures you choose based on what your party can handle (more on that in a moment).

The DMG also specifies to apply a multiplier to the creatures' overall XP value based on how many of them there are. This is the DMG table to describe this:

Number of Monsters	Multiplier
1	x 1
2	x 1.5
3-6	x 2
7-10	x 2.5
11-14	x 3
15 or more	x 4

So a single creature is just taken as-is: a single CR1 creature is worth 200xp, exactly how it's listed in the Monster Manual. Two CR1 creatures would be worth 600xp ((200 + 200) * 1.5), putting them well-above the deadly threshold. This is because the Action Economy in 5e is very important: the more actions a creature (or group of creatures) get in a round of combat, the more powerful they are.

There are also guidelines for adjusting this multiplier based on the party size, but 4 characters is the standard for D&D party sizes, so no adjustment is necessary. Refer to the DMG yourself if you end up DMing for a party of 2, or for a party of 6+.

Finally, you need to consider the strength of the creatures themselves. You could just use Monster Manual entries to populate your games, but if you need to tune your encounters, or make your own enemies for the players to fight, you'll want the table from Chapter 9 of the DMG, under the subsection "Creating a Monster", which describes possible stats for created monsters. I've copied a small portion of this table here:

CR	Prof.Bonus	AC	HP	Attack Bonus	Damage/Round	Save DC	XP*
0	+2	≤ 13	1-6	≤ +3	0-1	≤ 13	0 or 10
1/8	+2	13	7-35	+3	2-3	13	25
1/4	+2	13	36-49	+3	4-5	13	50
1/2	+2	13	50-70	+3	6-8	13	100
1	+2	13	71-85	+3	9-14	13	200
2	+2	13	86-100	+3	15-20	13	450

^{* The column for XP values was added by me, and isn't part of the DMG's original table}

Note that, for the most part, these numbers are "ballpark" numbers. If you look in the Monster Manual for CR1 creatures, you'll find no creatures that have hitpoints greater than 65, and only 5 (of about 30-40) that have hitpoints above 40. Conversely, almost half of the creatures at CR1 have an armor class higher than 13, or an average damage greater than 14 points per round.

These numbers are guidelines, not hard-and-fast rules

Some parties are going to be more capable than others. A party that keeps a paladin well-protected is going to be very difficult to kill off; encounters that normally rate as "deadly" often rate less so with a paladin in the party, especially as their higher level abilities begin to come online. Conversely, a party with no dedicated healers will often lose party members in even modest fights, since a single character going unconscious can sometimes be enough to outright kill them.

The best advice I can give is that you err on the side of safety in the first few encounters you throw at your players, and try to gauge what they are capable of. Then, you can begin to up the difficulty as you get a feel for their ability to recover from damage, their ability to beat down enemies, and so on.

Answer 2

I honestly recommend just running a small simulation of combat and tweaking it accordingly

I usually do that with my games, I make the encounter how I think it's balanced, see how the fight goes and I try to have the party win comfortably, why? Because I know that there's always a chance that the party does dumb or even sub-optimal stuff, so it's always good to have that window.

That and, just blunder a couple of enemies if things take a big south turn, nothing assures you that an encounter will certainly not be deadly, because for all we know players could roll very bad and then shit happens.

I know there are some encounter-based websites out there for those things but, In my opinion, I like and prefer the old fashioned way of playtesting, it's fun, lets you also understand your player's characters and it can even give you ideas for future reference on how to challenge them.

Answer 3

I recommend using Donjon, an incredibly versatile tool

Donjon takes into account the calculations for encounter size. What's more, you can create random encounters by terrain type using it. For example, you can select level, number of players, and terrain type, and the random generator (link below) will pop up a bunch of appropriate encounters along with their difficulty, exp budget, and even Monster Manual page to help you with them. You can even create a random dungeon level appropriate and as complex as you like with it.

Fantastic tool for DM's, and especially great for 1-shot games.

Random Encounter Generator

Encounter Size Calculator

Random Dungeon Generator

Answer 4

Other answers have covered all the tables and tools sufficiently, but those aside, be aware that 1st level is weird and tricky. ("Swingy" is a term often thrown around.)

The higher your level gets, the more your battles will tend towards the average, because victory simply requires more dice hitting the table (whether that's a fireball's pile d6s or just a fighter rolling a dozen-odd sword attacks over the course of the fight). More dice means the extremes tend to balance each other out for a more average overall result. So as you level up, the XP budgets and difficulty estimates become more reliable. At first level in particular, a goblin who rolls a single crit can easily drop any character in the party, and a run of lucky hits with good damage rolls could put half of the group out of commission before they can even think of retreat, even if they're making good tactical and strategic decisions.

Contrariwise, it's just as easy for the dice to go the other way, and the PCs could falsely feel like they could cut through miles of goblins without breaking a sweat.

It might be a better idea to have a one-shot using level 3 characters that are a little more capable and survivable, and a little less subject to the whims of the random number generator. I'm not saying you can't run Level 1 heroes through a short adventure; just be aware that the players might lose through no fault of their own.