Home Articles The Fundamentals of Combat Encounter Design for D&D

The Fundamentals of Combat Encounter Design for D&D

by Jae
combat encounter

Combat encounters are critical to running a successful Dungeons and Dragons campaign. As a DM there are plenty of times where you’ll be put in a position where designing engaging and thoughtful encounters will be a must for an upcoming session. So how do you go about designing an encounter? What makes an encounter good? How do you handle pacing and flow of combat? Let’s answer all these questions by tackling the fundamentals of encounter design.

What Is an Encounter and What Makes an Encounter Good?

Encounters are the scenes in your DnD game in which your players take actions to overcome challenges. These fall into two major categories: combat and non-combat encounters. For this article we will be focusing on combat encounters or any encounter where players have an opportunity to use the combat rules of the game. Keep in mind that when designing an encounter for combat there are often many solutions that do not involve violence and players will often have some control over how combat-heavy their game is to an extent.

Good Encounters

So what makes a good encounter? That depends on your group, but in the broadest sense, a good encounter is one that gives your players a wide array of options for how to overcome a challenge. Players will come up with different solutions for the challenges they face depending on the type of skills they have at their disposal. A martial-heavy party will rely more on brute force while a magic-heavy party might utilize a wide variety of spells. Rogues and rangers have options for stealth and cunning while bards might try to talk their way out of trouble.

No matter the encounter you’ve set up, the solutions available should be ultimately be determined by what the party wants to try. There should be no one set way to approach a scenario, even if you build in specific elements they can use to their advantage. The best encounters can have unique outcomes no matter how many times you run them.

Balancing Encounters

Before we talk about selecting enemies, setting up locations, and working out encounter synergies, we need to talk about balance. Balance is a very important part of Dungeons and Dragons. It’s what keeps the game fun. Too easy and players may lose interest, and too hard and players may get frustrated or feel like they have no chance to succeed. There are a ton of ways to balance the game overall, but for combat encounters we’re going to focus on two main items: CR and action economy.

Understanding CR

Challenge Rating, or CR, is a numerical representation of how difficult a particular creature is for a party of 4 adventurers. These numbers are applied to enemies within the Monster Manual and represent the average level that a party of 4 would need to be to have a fair fight with that creature.

So for example, a creature with a CR of 1 is an even match for 4 level 1 adventurers. A creature of CR 5 is an even match for a party of 4 level 5 adventures. While this is a handy system, it is often not fully sufficient to create balanced combat on its own. The CR system is more of a guideline and overall challenge rating does not take into account a lot of scaling issues than need to be addressed in the game. Because of this, we use CR as a simple numerical representation of how difficult a fight is from an endurance level.

The real problems come in when you start looking at the combat itself. A CR that is higher than your party’s level may not be more deadly, but instead could take up more resources to overcome. These would be monsters with high armor class or high hit points and no real special abilities. In a similar vein, a high CR monster might be extremely deadly on its own, but easy to defeat if you get the jump on it. These details are things that CR fails to represent, so to handle these balance issues we turn to the action economy.

Understanding Action Economy

Action economy is a measure of how many actions happen on each side of a combat. If you have 4 players fighting one monster, assuming they each have 1 action per round, your players would have 4 actions and the monster would have 1 action every time you complete one full round of combat. In cases like this where the players have more actions than the enemy they are highly likely to win even if the CR is 1 to 2 levels above the level of the party.

Conversely, if you have a larger group of weak monsters,  say 10 goblins, then a party that exceeds the goblin’s total CR would still have some trouble, as the goblins act 10 times each round, which would be hard to deal with for anyone.

Because of the issues with CR not being a good measure on its own, the action economy is a supplemental element that you can use to determine if you have the appropriate balance for an encounter before you pick opponents. A default balance will have equal CR and action economy. The two numbers can be played with and fine tuned to create more robust encounters when planning out your enemy selection.

Be sure the number of actions on the enemy’s side never becomes excessively high. Even if the CR is under the balance point, once actions get in the realm of double or triple that of the players you get long combat encounters that the players have little to do between their individual turns. While this might be balanced depending on how it’s set up, it’s not often fun for everyone at the table.

Encounter Creation

Now that you understand CR and action economy, you can finally start planning an encounter. For a good combat encounter you’ll have to consider the location, the enemies, enemy interactions, location interactions and the loot/items in the scene. None of these are complicated on their own, but setting up an encounter is about how each piece works together. Let’s break them all down and explain how to go about setting things up.

Location and Battle Maps

Location is important. Even if you don’t use battle maps for combat, the location should play an active role in the combat choices that your players make. Things like the ease of movement, available cover, or hazards that can work for or against the player all make for a rich combat encounter. Let’s examine elements every location has a little closer.

First we need to know the type of location. This tells you a lot about what is going on and is almost always decided based on the larger quest the players are on. Typically there are a handful of location types that change how the encounter works, namely natural vs man-made.

Natural settings like caves, forests, or deserts all have built-in elements and a collection of natural enemies you would expect to see. Man-made locations like dungeons, towns, or keeps will have relatively flat combat surfaces and the enemies within them will be very purposeful and specific to the story. After all, you don’t expect to run into a pack of wolves in a tavern. Once you have your location in place, note it down; you’ll come back to it in later sections of encounter planning.

Second, we need to know the size of the location combat will be taking place in. If the heroes are entering a cave it will likely be rather cramped, or if they’re in an open field it would be quite spacious. You should consider the size of the location first because it determines how your players and the enemies can move.

For example, small dungeon corridors make it hard for all the players to get out front and attack, but the monsters have the same issue. In these situations you end up with a lot of time spent positioning and possibly missing actions. With available space in mind, you’ll also want to decide if your area should have multiple elevation levels as well, something we’ll touch on again when we talk about hazards and difficult terrain.

Once you understand the size of your encounter location, it’s a good idea to draw out a rough battle mat if you don’t already have one. If you’re not the drawing type, this would be when you search for a battle map online that fits your needs. There are thousands out there to choose from.

Next we want to consider cover. If you have enemies or players that will be able to use ranged attacks, cover might be quite important in your encounter. While both a field and forest are large areas where players have a large freedom of movement, the forest offers ample locations with cover and makes ranged combat more difficult.

If you’re in a bigger dungeon room, cover should be expected in some form or another; try not to have empty rooms. In nature trees and rocks populate a map while buildings and dungeons have furniture, crates, or thematic set dressings. As a rule of thumb try to ensure that you place cover logically in a map. You don’t have to overdo it.

With a battle map and some cover placement already considered, it’s time to look at difficult terrain and hazard placement. These are not a requirement, but they add a lot to the encounter and change the difficulty of the fight depending on how they’re placed. Simple difficult terrain can be things like soft sand or tangling vines. It simply slows anyone who attempts to move over it.

There’s a whole lot of different options for it, but if you want to make it more advanced you can bring in things like thin ice, elevated areas, or ball bearings. Make sure to note their locations on the map and consider how obvious they are to the players if you’re planning on using any of these elements.

Once you’ve thought through these items you’ve got a rough location planned out and you’re ready to move on to enemy selection.

Picking Enemies

Picking enemies can be tough. There are a ton of enemies to choose from and a near limitless number of combinations that make sense. The good news is that since you’ve already picked out your locations you should have a good idea of what type of enemies make sense.

If you’re in a natural location, you can find enemies from that biome that will be a good fit and consider them a starting point. Alternatively, you may have a man-made setting; in that case you’re likely choosing either dungeon monsters or humanoids for your players to fight.

After you have a list of potential ideas you’ll want to jot down your group’s CR and the total number of actions they take per round. Once you have those in place, cross off the enemies that are too far out of the CR range or would take too many actions per round as opposed to the heroes. My cut off is 4 CR above or a number of enemies that take 3 times the party’s actions, but your specific cutoff might vary.

Next, start looking at the remaining monsters to consider their fit against your group. I always check to make sure monsters can be defeated by my group. Depending on the group, this might rule out werewolves or ghosts or other monsters with resistances they cannot handle for some reason. Some groups are also too good a fit for some enemies and might line up with monster weaknesses. If that is the case, the best option is to push the CR a little higher and add an additional monster.

From here I’ll start considering if I want a homogenous group of monsters or a mixed one. Fighting all one type of monster can be very different from fighting two types of monsters at once. An Iron Golem and a magma mephit are much harder than the sum of their CRs. The mephit can heal the golem with “heat metal” and can hide in magma. This easily doubles or triples the golem’s potential HP and makes the combat much harder.

If you are choosing mixed monsters it’s best to consider the roles of the monsters like that of a party. Each should have a part they play. Assuming the monsters are smart enough to work together in the first place they will likely divide up their roles to achieve a core goal.

If this all seems like a lot of work to you, it certainly can be! Good encounter planning takes time, but there are tools to help with that. Things like Kobold Fight Club can make the whole process much easier. We also highly recommend the book The Monsters Know What They’re Doing by Keith Ammann, which can really help when it comes to figuring out monster tactics and pairings.

Enemy Interactions

It’s not enough to have chosen some monsters for an encounter. Good encounters will have additional planning steps to figure out how the enemies are going to interact with the environment and the players. Goblins, for example, are hit and run fighters who understand how to use cover and stealth to really ruin an adventurer’s day. Understanding this simple interaction between the enemy and the environment will help you when it comes time to actually run the fight.

Taking the same goblin example, we know if we put them in a wide open space they’re not likely to find cover and may flee easier or look for alternative combat options. You can usually figure these types of interactions out simply by sitting down and reading over a creature’s descriptions and assuming the creature’s goals are often aligned with their own long term survival.

Location Interactions

Understanding the interactions of your environment is just as important as understanding the interactions of your enemies. Are you in a swamp that will slow movement? You should have notes on when that applies and what the specifics are. Are there bear traps in the forest that both players and enemies have to avoid? That’s a neat interaction, but requires knowing where the bear traps are and how to handle them going off during combat.

These interactions don’t need to be overly complex, but every location or environment has something unique about it. If you’re fighting in a tavern, you can make improvised cover by flipping a table. Alternatively, you could set the tavern ablaze by igniting the liquor behind the bar. While these are common sense interactions, noting them out ahead of time will really help when you get into the actual encounter itself.

Generating Looting Tables/Treasure

Looting and treasure come with any successful encounter but can be a real pain to take care of on the fly. Every now and then you will get someone who wants to take every enemy weapon, piece of armor, knickknack, or anything that isn’t nailed down. To avoid having to figure this all out on the fly, it’s often easiest to write out a few simple loot tables for each encounter.

Essentially anything the party might find while rummaging through enemy pockets or containers in the area. This ultimately saves a lot of time and more often than not the tables can be reused in other areas just as easily.

It is also advisable to put together a generic pack of items that any enemy you use often in a session will have on them. If you’re running a low level fight against a bunch of goblins, don’t equip each one individually. Make a standard set of equipment and a random loot table for miscellaneous items they might have on them.

This saves a ton of time whenever you have sessions full of stock bad guys. Henchmen, cultists, koa-toa, bandits, you name it. These generic enemies can all have a single loadout and random loot table and your players will never know the difference.

The only thing you need to worry about beyond generic loot is your key items. Anything that is story relevant or important for progression should never be left up to chance. Even if you have your players roll to find something, key items should be found 100% of the time with whatever else they manage to discover in their roll.

Encounter Strategy

You’ve got your enemies placed in your location. They’re all stated out and looted up. So you’re done, right? Unfortunately, no. This is where the real encounter building begins. From here on out you focus on the enemy’s strategy. You figure out why the party and the enemies are fighting and design your play around these reasons. Once you understand these things you can have more interesting combat scenarios. Let’s dive into how strategy brings these encounters to life.

Monster Intelligence

Let’s talk about monster intelligence. While not all monsters are intelligent in the sense that they could talk or read, all monsters are intelligent in the sense that they know how to survive. The world of Dungeons & Dragons is exceptionally dangerous and monsters, no matter how dumb, will have to have some sort of survival instincts to stay alive in this world.

With this in mind, the intelligence of your enemies often determines the complexity of their strategy. Wolves might use pack fighting tactics in which they rely on grouping up around individuals who are separated. When they are hurt they might run away, and if enough of the group is hurt or flees, they all will abandon the fight if they can. This might sound relatively intelligent, but it’s really just common sense for them. Why would a wolf want to fight to the bitter end? It wouldn’t. It’s only goal is survival.

Humanoid enemies might have more complex strategies. Goblins use hit and run tactics. Bandits might set up traps. Cultists might abandon survival ideals in the pursuit of their dark goals and fight to the death. These ideas all require a bit more intelligence, but they require you to know about the enemy and apply some logical reasoning.

Enemy Goals

Typically, enemies are not fighting adventures for no reason. Usually the enemy has a goal. Even undead, who will attack relentlessly, have a goal: kill all living things. Understanding this goal is what makes combat interesting. Using bandits as an example, they are trying to get valuables. So if they can steal an adventurer’s pack or run off with a horse, they might exit combat altogether.

In other scenarios the enemies can be defending themselves, their home, or something else and the adventurers are the antagonists in the situation. With wild animals and monstrosities the goal is usually survival and/or acquiring food.

Knowing the goals of your enemies will tell you a few key pieces of information:

  • Will your enemies run away? If so when?
  • Are there alternative ways to meet that goal?
  • How important to the enemy is this goal? Is it worth dying for?
  • What is their risk tolerance?

These questions become clearer when you know what your enemies want. Depending on the situation, you might find some really amazing outcomes and ideas just from thinking about what the enemies are trying to accomplish.

Non-Combat Resolution Options

Depending on the goals of the enemies, there may be peaceful means to resolve an encounter. Bandits might surrender rather than die. Guards might be willing to be bribed. Beasts might even be placated with food rather than fight. When peace is an option you’ll need to know if the NPCs can speak. Have some names jotted down and get a good sense of what information they will and will not exchange.

If you’re not great with improvising NPC dialogue it can be a good idea to work out a path the NPC will push the narrative beforehand. Often in exchanges of these nature, where combat was previously on the table, both parties will have very little trust in the other. It’s also good to consider that communications can break down at any time, especially if one group feels it has an advantage over the other.

Defining an Encounters End

When is an encounter over? This might seem obvious, but there is usually a point in which you need to discuss the aftermath of the situation and usher your players onto the next scene. By clearly stating in your notes where an encounter ends, you can prepare for the next steps more easily and be ready to carry on with the session.

Encounter endings are typically when one side is dead or when they have fled, but other outcomes might come up. Capturing a target, interruption from additional enemies or friends, or a time based plot device can all signal the end of an encounter and move the party from combat back to role playing.

Writing Up an Encounter

You’ve gotten this far and I bet you have a ton of notes for your encounter. But keeping everything organized is just as important as making the notes in the first place.

General Organization

There’s really no wrong way to organize an encounter. If you value efficiency and flow in both combat and story, you’re likely going to want a one page writeup for the encounter with everything you need. For my games that contains the following:

  • A thumbnail of the battle map with DM footnotes (traps, type of terrain, enemy placement, etc.)
  • A brief description of the setting
  • Simplified stats for each enemy type (HP, AC, basic attacks, etc.)
  • Notes on goals and strategy for the enemies
  • Specific rules for enemy spells or level hazards
  • Loot tables

This might just seem like everything we’ve talked about so far. It is, but the important thing is that we’re not writing out every little detail. We’re noting the most useful pieces of information and nothing more. Enemy HP and AC are super important, but I don’t need to know all of their stats all the time. If we know my party casts spells that need saves, we’ll note those ahead of time too.

There are a ton of ways to write these encounter notes up, so the best advice is not to overthink it, just detail out what is important. As you run more encounters you’ll find out what is important to your group and you’ll refine your own style of note taking for encounters.


After your high level notes are all in order you’ll want to write up any major events that can happen in your encounter. If there is a fight in front of a dam that can be broken, here is where you would write up that trigger and what happens after that takes place. These can be very minor things, but it’s very important that you consider, at the minimum, what causes a change in the encounter and detail the effects that will apply to your encounter.


Descriptions are easily the part of note taking that gets the most DMs into trouble. Too much or too little is a constant struggle, but as a rule of thumb you’re more likely to create descriptions you never use than not have enough. When making notes for descriptions you can be straightforward; detail the physical information you need to convey with information for how your players may interact with something.

Beyond that, it might be helpful to write up a bank of descriptive adjectives you can pull from so that your narration doesn’t fall apart when you need to do a little bit of improvisation. Description notes are up to you, so write what you need to get through a scene.

Relevant Notes on Enemies and Location

Enemies are often placed in specific positions for a reason. Their abilities might have certain ranges, they may have specific things they plan to interact with, or they might even be critical to a plot element in a certain spot. These notes are important, so much so that we’ve called them out again here.

If you need your enemies in a certain spot for a certain reason do not forget to write it down. It’s so tempting to tell yourself that you’ll remember, only to find mid-combat the enemy you need to pull a lever is nowhere near it and the heroes win the day due to poor note taking (totally not speaking from personal experience…).

Encounters in the Context of a Session

At this point you have a full encounter. It’s written up and can be mixed and matched into any applicable game, but likely you already know where it goes. Encounters are just a small slice of any D&D session and you should always think about them in the context of the overall plot.

Multiple Encounters Between Short Rests

According to the Dungeon Masters Guide, encounters often happen multiple times between short rests. While you might be tempted to make a super challenging encounter, consider how that works in the larger context of the session. Will it deplete your team’s resources? When will they be able to fight again? Can they handle three or more encounters in a row?

Often if you look at an encounter from the perspective of a party at full health, it will seem like it’s easy. But how often do your players enter encounters well rested and ready to fight? In a  single session players might go from one fight to the next in rapid succession.

This will mean that the easy fight you had planned later in the session could be super hard now, or the boss fight is now something the party needs to flee to survive. Think about how encounters relate to other events in your game during planning so that you can provide a better total experience.

Encounters on Their Own

While you’ll often be stringing your combat encounters together, you can get really creative with stand-alone encounters. A single encounter in any session should be notable. Think about the story you want your players to be able to tell when they recount their epic adventures.

If your session is just going to have one encounter, you can do more with it to make it more dangerous, interesting, or noteworthy. By taking steps, you’ll be sure your players can think back to any session and have fun memories to retell.

Running an Encounter

It’s game time! Let’s look at some notes to keep in mind when running your encounter. We won’t be covering individual combat rules, but instead be looking at some tips for managing the encounter itself.

Pre-Combat Scenarios

Before turn one even starts, you’ll be figuring out how the encounter is going to begin. Are your players sneaking around the enemies? Are the enemies hidden and waiting to jump out on your players? Is it a straightforward kick in the door scenario?

Thinking through the ways your players might interface with a combat scenario is helpful, but when you actually get to the encounter, be sure to ask your players what their plan is. They’ll often describe things in the terms of outcomes, and then combat begins as their plan either works or fails and you explain how things deviate from their ideal.

Initiating Combat and Turn Order

Initiative is triggered when you enter into the traditional phases of combat. Asking your players to roll initiative comes whenever a combat action would be the next step that is taken. If you have a lot of creatures you’ll want to get your turn order written out. It’s easy to lose track of who needs to do what and when.

If you want to keep things flexible, you can write out notecards for each unit and stack them in turn order. This way after someone acts you simply move their card from the top to the bottom of the pile. This method is easy and reliable, plus it saves you from re-writing the turn order if something happens to change it.

Playing Monsters vs Playing Humanoids

Each monster or humanoid will behave in its own unique way. When you’re playing out your encounters, pull from your notes on the creature’s goals and be sure to ask yourself why they are taking their action before they do so each turn. Monsters are typically in survival mode, so asking yourself if this action is useful to their survival will help with your choices. Humanoid creatures will make more value based decisions, but if you’ve noted out their goals you can easily ask if an action is worth the risk and evaluate your moves carefully from there.

Ending Combat

Once combat wraps up it is your job as the DM to dip right back into the narrative. Often the easiest way to do this is to narrate the final kill in a combat and transition right into talking about the aftermath of the battle. In the case where there are survivors or individuals to talk to transition from description to role playing right away to keep the pace moving.

The major exception to this is where you are either ending a session or your players make it clear they are taking a rest. Sometimes combat ending is a good wrapping up point. Sometimes continuing on is just too much for the group, so be ready for either scenario and tuck the remaining or unused descriptions away for later, you can always come back to them.

Resolution and Looting

We’ve already touched on looting a bit in that you should roughly know the basics for any area and what key items are around, but additional loot should typically be rolled for. You may have mixed feelings on how loot should be distributed and how much luck should play into the scenario, but rolling for a loot table essentially tells a player how thorough their search was and if they were lucky.

In the cases where a player describes how they want to search a room and how carefully they want to look for loot, it is advisable to grant advantage or disadvantage based on the description they provide. This let’s their actions have more agency while still taking advantage of luck based components.


When you’re starting out, encounter design can seem intimidating. But it’s a skill that takes practice like everything else. Remembering your building blocks when putting an encounter together will help you create exciting and engaging combat for your players. Thinking carefully about locations, enemies, and rationale for their use will help you elevate your encounter building in no time. Just start simply and try to build up something new each time. Sooner or later you’ll be pumping out astounding encounters like it’s nothing!

Happy DMing!

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