Enemy Design in Games: A Beginner’s Guide

What is Enemy Design?

In game design under game development, the enemy design covers the design and creation of tactics, visuals, behaviors, strengths, and weaknesses of hostile NPCs. The entire process is a collaboration between game designers, game artists, game writers, game animators, game programmers, and sound designers to create challenging, exciting antagonists.

As hostile NPCs who get in the way of player goals, enemies help to define gameplay.

Game enemies must offer the player a fun challenge that encourages using abilities/resources at an appropriate pace without frustration.

Consider the overlap between enemy design and gameplay in a classic title like Dead Space.

The Necromorphs of the Ishimura were quite unlike previous video game zombies (as were many of the improvised weapons). Shooting these enemies in the head or chest was ineffective and could cause them to accelerate toward you:

Dead Space’s enemy design forced players to adopt the tactical dismemberment strategy, first cutting off the limbs of approaching Necromorphs.

Limited ammo and improvised industrial tools for weapons added to the tension.

The concept of the Necromorph (and how it relates to gameplay) probably started as an idea on paper.

Bringing such an idea to life is a complex collaboration across writing, art, animation, programming, sound, and AI teams.

This is the process of enemy design.

Why is Enemy Design Important in Game Development?

Enemy design is important because enemies motivate the players to push forward while testing their understanding of gameplay.

From a narrative design perspective, great stories need great antagonists—whether in games or non-interactive mediums like books and movies.

(Although game developers can adapt parts of enemy design from film, TV, and literature, player agency and interaction are where games differ most from other media.)

When I designed the Warlock class for World of Warcraft, I began to fully appreciate the role of quality enemy design.

No spell, ability, or buff could feel exciting without an appropriate foil—enemy design is that important.

What’s the difference between enemy, combat, and encounter design?

Enemy design, combat design, and encounter design are terms with some overlap. However, each term refers to a distinct part of the game design process.

Enemy design: Enemy design refers to creating the visuals, sounds, tactics, motivations, behavior, stats, and weapons of individual enemy units.

In the context of Super Mario Bros 3, designing the looks, sounds, movesets, and attack patterns of the Boomerang Bros and  Hammer Bros are examples of enemy design.

Combat design: Combat design involves determining how combat mechanics play out during interactions between the player and hostile NPCs. It looks at the building blocks of combat at a fundamental level and defines a game’s combat mechanics.

Combat design in something like Super Mario Bros 3 would involve prototyping, testing, and iterating on how Mario and Luigi’s movesets interacted with those of enemies, the engine’s physics, and the environments.

At this level of design, the arenas for combat can be mock-ups of what will end up in the final product.

The point here is to create combat mechanics that feel satisfying on their own merits.

Polish, player motivation, and integrating combat into the game’s progression systems can get figured out later.

Encounter design: Encounter design refers to the who, why, when and where of specific in-game combat encounters happen between the player character and the NPCs.

As you can see above, encounter design is the overlap of a game’s level design, combat design, narrative design, and character and enemy design paced throughout the game’s flow and progression systems because it involves creating sequences of plot-triggered combat challenges by enemy AI appropriate to the player’s level/skill.

To use the Super Mario 3 example again—encounter design means choosing when, where, and in what numbers the player encounters enemies.

Choosing Pirhanna Plants for this section and Venus Fire Traps for that one is the work of an encounter designer:

What are the different types of enemy design?

Many elements make up a video game enemy. It’s visuals, mechanics, class, behavior, and more should engage the player on a visceral level while offering a satisfying challenge.

Each of these components requires careful consideration, testing, tuning, and iteration.

All of the following areas fall under the category of enemy design:

Enemy mechanics and combat design

Most enemy mechanics are combat mechanics that determine the enemies’ combat design. Some games like CRPGs and turned-based RPGs are up-front about how their enemy game mechanics work and the importance of understanding them.

AAA titles often simplify mechanics at standard difficulties in their quest to appeal to the broadest possible audience.

This meme sums the situation up for many gamers:

There are 4 types of enemy’s (combat) mechanics:

1. Offensive
2. Defensive
3. Buff
4. Debuff

Picture it like this:

Playable characters feel different from one another when their mechanical options are different. The same should ring true for enemies.

Hostile NPCs should feature carefully considered mechanical options that the player can read and counter.

Figuring out the bad guy’s mechanics is half the fun.

An example is the Harpy fight north of the Emerald Grove in Baldur’s Gate 3:

After taking a beating on your first attempt, you quickly work out the devastating effect the Harpy’s Luring Song ability can have on your party.

Understanding the mechanics of this one ability is key to winning the fight.

Blessing your party before the fight (to increase resistance) and aggressively targeting the singing Harpy with ranged attacks and spells to break their concentration gives you the best chance.

In this example, the Harpy’s mechanics define the fight and the abilities you must use to succeed.

First- and third-person action games don’t lay enemy mechanics out before you, as in an isometric RPG, but those mechanics are present nonetheless.

Consider the different tactics you use in the Halo series when fighting Grunts vs Elites. The mechanical design of these two enemies forces you to adapt your gameplay.

Grunts pack weaker weapons, take fewer hits, and only attack aggressively in numbers—hoping to overwhelm positions with sheer volume.

Players can deal with swarms of Grunts using grenades, automatic fire, and pushing forward with melee strikes.

Elites’ lower numbers are offset by their Energy Swords, Plasma Rifles, armor, intelligence, and resolve. Their mechanical design means players are better off finding cover and targeting these Elites with high DPS weapons from range.

Enemy character and class design

Another reason why the enemies in a series like Halo work so well is how distinct each enemy unit feels within the game’s fiction depicted here:

This feeling of clear distinction is a result of quality enemy character and class design.

In the same way that the player is supposed to represent a kind of idealized, story-resolving archetype (wizard, rogue, Master Chief, assassin, etc.)—each enemy should fulfill a narrative and mechanical purpose in the game.

In this GDC talk, Massive Entertainment’s Philip Dunstan & Drew Rechner discuss the challenges of creating unique-feeling factions, archetypes, and skills for enemies in The Division:

Players would rather fight an enemy with an in-fiction reason to exist that poses a unique challenge than a bandit or zombie with a single attack routine and a stack of hit points.

The Witcher 3’s use of different classes of enemies in different locations is a great example.

Drowners near rivers, Sirens in the ocean, and Grave Hags near burial grounds (to give just three examples) enhance the sense of place and force the player to adopt different approaches depending on their location:

Character artists, game designers, writers, animators, and programmers all play a role in creating and implementing immersive enemy character classes like those in The Witcher 3. (As did the literary work of Andrzej Sapkowski.)

The Witcher 3’s memorable enemy roster led to player selfies like this:

A big part of how enemies show their character, personality, and class archetype is through barks (the lines of dialogue that trigger when the player is within earshot).

To return to the Halo example—consider the Grunts panicked shouts and grunts and how they affect our perception of their character class like

• “The gross bug just touched me!” (That’s you they’re referring to, Master Chief!)
• “I trained three days for this moment.”

Without reading any novels, background lore, or codex entries, we understand that these characters are not highly trained specialists.

Enemy tactics and behavior design

An enemy’s tactics and behavior should reflect their narrative and mechanical purpose.

For example:

• Sentries patrol routes set out by AI programmers, deviating when certain defined criteria are met.
• Berserkers rush forward, heedless of danger or damage.
• Snipers and ranged enemies look for cover and elevation to increase their chances.

Yes, these actions facilitate gameplay and can direct the player toward a goal, but they also make sense in-game.

Series like Hitman and Dishonored feature enemy NPCs whose behavior looks and feels convincing while offering the player gamified opportunities to exploit routines.

This video from Gamer4Sight details some of the most creative kills from Hitman: Absolution Seasons 1 and 2:

For another example, consider how revolutionary enemy behavior felt (for the time) in Metal Gear Solid 2: Sons of Liberty:

Enemies would work together in squads to flank the player and cut off escape routes.

These behaviors were carefully planned, tested, and tweaked to offer players the best possible experience.

Nonetheless, Sons of Liberty players found myriad ways to break and exploit the game’s AI with fun results:

Players feel immersed when enemies act in a consistent and logical way.

That’s not to say players want to be overwhelmed by ultra-intelligent, hyper-aggressive enemies, but they do like when enemies act like they understand their own abilities.

To return to the example of the Harpies in Baldur’s Gate 3 (though I concede some players might be traumatized like the creator of this image):

One Harpy will always hang back out of melee range, hoping to ensnare victims with its song.

Once Luring Song incapacitates its victims, the other Harpies can eviscerate the party with their slashing damage.

This behavior signals to the player that the enemies understand their own strengths and weaknesses.

It also helps the player to recognize and exploit the enemy’s vulnerability using their party’s skills. (There are several ways to interrupt the singing creature.)

When I redesigned the Warlock class for WoW, I saw the importance of having enemies that encourage the use of the players’ fun abilities.

For example, the Warmaul Champion in the Burning Crusade is immune to crowd control and always charges at the most distant member of your party.

These tactics and mechanical design disrupt a Warlock’s usual tactics to defeat the enemy, forcing the player to adapt and work in a team to succeed.

If part of the class’s ranged attack is its capacity to interrupt spells—you’d better have some enemy spellcasters for the player to flex on.

Part of the fun in gaming is figuring out the optimal way of beating the challenge, implementing that strategy, and making what was once challenging simple.

Enemy behavior is an important part of this puzzle.

Enemy encounter design

Enemy encounter design refers to the when, where, and in what numbers/configuration players meet the enemy combatants and monsters.

This area of enemy design overlaps with combat, AI, narrative, and progression systems because encounters must

1. Have scenarios where the enemy AIs provide satisfying combat gameplay
2. Is contextual to the narrative including world and character lore
3. Challenge the player according to their current ability/level

Fun encounters play to a game’s strengths, limiting player interaction with parts of the game that are less polished.

For example, Gears of War’s cover mechanics felt so fun that the designers focused on creating encounters with lots of cover options for players.

This video from The Escapist details what made many of Gears of War’s encounters so memorable:

What Does Engaging Enemy Design Look Like?

Effective enemy design means creating NPCs that add to the experience.

The more ways a game does this, the better its enemy design.

Analyzing great enemy designs from classic games like the Doom series can help budding designers nail down their own ideas.

Doom has always featured unique enemies with compelling lore, distinct, readable tactics, strengths, weaknesses, and nightmarish, Giger-esque visual design—as seen here:

Here are some high-level considerations for enemy design:

1. Enemy uniqueness

Each enemy type should look, feel, sound, act, and move differently. This is more than creating variety for window dressing.

Unique enemy types require us to adopt a range of fresh tactics, tools, and abilities—they give the players a reason to press forward, which increases overall game depth.

8-bit and 16-bit gamers know the excitement at seeing a genuinely new enemy type and the disappointment of a simple color palette swap.

Players generally accept that assets are reused in creating NPCs, but they appreciate it when developers make an effort to keep things fresh.

This meme sums it up:

A new enemy should represent a new challenge, a strain on resources, or hint at a potential payoff in narrative or progression terms.

2. Enemy readability and telegraph

Enemies should give players consistent audiovisual feedback that facilitates learning patterns, timing, and tactics.

The deliberate cadence and sound design of the Dark Souls series’ enemies exist so players can learn its timing and adapt appropriate strategies.

Although rudimentary by today’s standards, Doom 2’s enemies featured highly readable characters and animation sets.

This slide from Matthias Worch’s GDC presentation on Meaningful Choice in Games demonstrates how to read enemy types in Doom 2:

3. Threat hierarchy

Can players quickly distinguish which enemies pose a major threat and which don’t?

Distinctive visuals, animations, and consistent tactics and behaviors allow players to assess which enemies pose the biggest threat. Based on this assessment (and enemy proximity), the player can choose which threat to focus on first.

This image (also borrowed from Matthias Worch’s presentation) shows how a player assesses the chief threat in Doom 2:

4. Emotional range, intelligence, and resolve

Some enemies will lose confidence as their odds of victory decrease. Others may grow more aggressive in desperation.

How do they show this?  

Halo’s Elites and Grunts offer another excellent example.

Elites fight to the death against any odds, maintaining an aggressive, confident tone in their actions and barks.

Grunts fall apart when their numbers diminish, using barks and animations to let the player know what’s going on.

Attack cadence: At what proximity can an enemy attack? What timing does it use when it initiates an attack? How many attacks can that enemy execute at once? What directions can the enemy attack from?

These are all questions that relate to attack cadence, an important, high-level feature of enemy design for action games.

Novel, Memorable Responses: One of the quickest ways to lose player immersion is to feature enemies that respond in the same cookie-cutter way to player action.

When enemies (or any NPCs) demonstrate dynamic responses, react meaningfully to player action, or deliver funny, situationally appropriate barks—players remember.

How to Design Engaging Enemies

Video game enemies exist to act as a foil to player actions and ambitions.

Some elements are universal, but different genres demand very different approaches:

• FPS enemies are like shooting galleries—readable targets that are fun to destroy.
• Mario or Sonic-style platformers need simple, quickly dealt-with enemies.
• Soulsikes and deeper combat games need dynamic enemies that players memorize.

However, there are some core principles to guide designers in creating enemies in general:

Step #1: Establish the enemy’s core function

Use these “why” questions around enemy designs can help you focus your design:

1. Why does this enemy exist from a narrative perspective?
   Follow up with:
   • What role do they play in the game world’s fiction?
   • What do they obstruct the player from doing?
2. Why does the enemy exist from a mechanical perspective?
   Follow up with:
   • How does their challenge fit into the player’s progression arc?
   • How are they a foil to the player’s abilities?
3. Why will the player want to engage with this enemy?
   Follow up with:
   • What parts of their combat mechanics, behavior, aesthetics, animation, and writing make them fun to interact with?

Let’s apply these three above questions to the Necromorphs of the Ishimura:

1. Zombie Virus: Dead Space’s Necromorphs are reanimated corpses given horrific new forms by an infection. They impede Issac’s progress through the ship.
2. New Skill Test: Necromorphs can’t be killed with headshots or shots to the chest. They force players to focus on taking off limbs. Upgradable industrial cutting tools become essential improvised weapons.
3. Subverted Expectations: Most shooters prioritize headshots. Necromorphs get enraged by them and charge the player. Dead Space’s gameplay felt like an inversion of what was standard at the time.

Step #2: Assess the current enemy roster

Having more than one enemy that fulfills the same function is redundant.

Memorable games have a roster of enemies that feel, look, and act unique while offering novel challenges.

Zelda: Breath of the Wild’s enemy roster offered variety across visuals, mechanics, sound design, and behavior.

Breath of the Wild’s enemies also featured a range of challenge levels.

This image is from a lively Breath of the WIld discussion on Reddit:

Look at the project’s existing enemy list and why those enemies are present in mechanical, narrative, progression, and tonal terms.

• What’s missing?
• What other fun ideas spring from the existing roster?

Start brainstorming once you’ve established what kind of enemy is underrepresented (and would bring something exciting to gameplay).

Step #3: Consider player abilities

The primary way enemies interact with the player (in most games) is through combat.

Great enemies should occasionally engage you at the limit of your ability, using up resources and forcing you to use what you’ve learned on your journey.

At other times, game designers will deliberately place lower-level enemies in front of you so you can feel the power of a new set of abilities, weapons, or spells.

Enemy design should focus on fun ways of teasing out player abilities.

Games like bullet hell shooters often have a limited number of strategies that players must learn and execute.

CRPGs, strategy games, and simulations often offer players a wide range of tools and an equally broad number of ways to succeed.

Asking the following questions can help with core enemy design ideas:

1. When will the enemy be introduced on the player progression arc?
2. How will encountering this enemy engage the players’ skills and abilities?
3. What resources will the player have when this enemy appears?

For example, when I worked on Ori and the Will of the Wisps, we focused on traversal and player power-ups meant creating enemy types to engage specific mechanics:

• Creatures like the blue slime slugs in Inkwater Marsh don’t attack, but touching these slugs causes damage, and they slowly crawl towards the player. Slugs add an extra layer of complexity to traversal.
  
• Players can use careful timing or Spirit Shards like Sticky (to stick to walls) and Triple Jump to get around this challenge.

Step #4: Prototype enemy

The process of testing your prototypes will vary greatly depending on what kind of project you’re working on.

However, game prototyping is necessary to understand your design’s strengths and weaknesses.

Creating a test arena with the appropriate objects for cover, flanking, or any other tactics that will apply in-game allows you to get a feel for the enemy design in context.

Some game engines may allow you to test your design without editing the game code directly, but in most cases, you’ll have to do some programming.

Step #5: Adjust the enemy according to feedback

There’s no substitute for seeing your idea in action.

Test your enemy in every scenario you picture them being used in-game. Get other members of the team to playtest your idea, too. A fresh set of eyes will often reveal things you missed on the first pass.

Use the results to tune your design’s stats and behaviors.

Step #6: Keep iterating

This one is self explanatory. If you’re unfamiliar,  checkout this guide on iterative game design process.

How to Learn More About Enemy Design

Enemy design is a much broader field than this short intro can cover.

To dive deeper into some of the concepts raised here, you can check out these resources:

• Crystal Dynamics’ lead combat designer Isaiah Everin’s comprehensive combat design guide.
  • There is also a wealth of info in his substack for budding enemy combat designers.
• Game design analyst Celia Wager shares how to design interesting player skill tests.