The Logic Behind Violence: a Primer on Combat System Design

Designing a combat system for a game is often a confusing ordeal for many. However, combat systems are becoming more and more refined. This year we’ve seen a breadth of amazing combat systems. Ranging from PvE games such as Horizon: Zero Dawn as well as The Legend of Zelda: Breath of the Wild to innovations in PvP titles such as Fortnite and the greatly anticipated Dragon Ball FighterZ. In this article I hope to shed some light on where to start when designing a combat system as well as clarifying on some of the aspects that play into combat systems, using various games as examples to illustrate my points. The core goal is to decide on the feelings that you want the players to experience, how offering the players meaningful choices forms the core of that experience, then I discuss the aspects that go into creating meaningful choice, namely awareness, multiple unique outcomes, and risk. Afterwards I look at how the player’s knowledge and execution can be tested by these choices and how a game’s difficulty curve plays into these, and finally I return to the topic of the feelings that you want your player to experience by designing a coherent power fantasy.

Where do I even start?

Putting aside the ever-recurring Ludology vs Narratology debate (specifically in this case: ‘I have a cool mechanic’ vs ‘I have a cool story’), the main answer I have is to think about combat systems in an abstract manner. The term ‘combat system’ I would define as ‘the rules through which the player interacts with conflict’. Now I realize this is extremely broad... and that’s because combat systems are. Combat systems are intrinsically woven into the fabric of every core gameplay experience.

Example:

Take a game like Animal Crossing: City Folk; a game which has no combat with entities. The player, however, has many conflicts they need to resolve. For example, keeping up with weeds is satisfying and, in my personal experience, does not feel like a chore. This is part of the player’s conflict with the world - he isn’t pressing the A button to swing his sword and defeat enemies, he’s pressing A to pluck the weeds. Conflict comes in many forms and creating the form that fits your mechanics and/or story is key.

Nearly every game features conflict because players look for the satisfaction they get out of tackling a challenge. This ranges from mental challenges in puzzle games to instant gratification when killing hordes of zombies. Players will naturally try to resolve conflict within games, however there are limits to how far players will go, which plays into my next point:

The core of your combat system revolves around the question “What feeling do you want the player to experience as they play through your game, and how will your conflict and combat system cater to this?”

Example:

Let’s look at Undertale; a game in which the player’s actions in combat directly influence the story of the game. Killing an important enemy directly influences not only the combat systems but also the game world - this had direct emotional impact on many players and works to strongly emphasize the importance of life within the context of the world of Undertale. The choices the player makes when resolving conflict directly influences the experience of the player and how they feel.
 

Often the defining feelings the player experiences are found upon success - getting that headshot or nailing that really tough jump. What is important is to create a power fantasy for the player. A stealth game gives the player a different feeling upon success than a hack ‘n’ slash. This subject will be touched upon further into this article.

Having an idea of what feeling you want your player to experience is an important first step. Defining that goal means that conceptually you are halfway there. Now we have to figure out what major aspects of combat systems you can leverage to bring your concept to life. Once you are aware of these, you can start thinking of how exactly to use these concepts when creating a combat system that properly lets the players experience what you intend them to.

How should my combat system test the player?

At the core of resolving conflict stands meaningful choice - how a player resolves conflict is a choice the player makes. Having a choice that is meaningful is what constitutes the enjoyment. Andrei van Roon (Riot Meddler when writing for Riot Games) wrote an excellent article on the subject of meaningful choice, defining the two components that are core to meaningful choice as awareness that the player is making a choice and varying meaningful gameplay consequences - meaning that every choice has a different consequence and these consequences have trade-offs that force the player to consider the various available options.

As the player plays a game, makes these choices, and resolves conflict, they naturally become more familiar with the choices available to them. Knowing this, it is key to realize that whatever it is that you test the player on needs to be dynamic. As the player gets better at the game, situations that have been solved before are choices that have been made before, and as such are not interesting - in other words, the player needs more difficult challenges to match their newfound skills and knowledge. It is for good reason that ever since Space Invaders, difficulty curves have been a standard feature in the games industry. Difficulty curves define how the game presents new variables to the player to consider in their decision making. It is very important to offer a smooth difficulty curve to your player, as the fulfilment of achieving mastery is one of the main intrinsic motivators for people in general, as per Deci, E. L., and  Ryan, R. M  in their 1973 book Intrinsic motivation and self-determination in human behavior. As an aside, since the specifics of who plays your game can vary so much, designers often introduce a difficulty settings to allow the player to choose a difficulty that fits their personal preference. The way a difficulty curve is designed, however, is the same between all difficulty levels.

Personally I’ve found that mechanics that revolve around both space and time are most elegant to stand at the core of the experience. Both are easy to understand, constantly affect the game, and due to the fact that they are ever-present, as well as having a lot of permutations, allow for much depth and variation. Offering a simple core mechanic allows you make sure your difficulty curve doesn’t start off with an entry barrier. The more complicated the core enjoyment, the longer it takes for the player to get started.

Example:

In Super Mario Bros, the player frequently chooses whether to jump or not. At first simply to jump on single enemies and get over simple obstacles. The concept of jumping is extremely simple and easy to understand. However, as the game progresses, more complex situations get presented to the player (i.e. certain enemy patterns, especially in combination with obstacles) and the player realizes the commitment that comes with jumping. After all, the player can jump only when grounded - by jumping, not only do they lose control (air control is less flexible than ground control), they also have reduced options simply by not being able to jump. They commit time to the jump and limit the space they can occupy as an opportunity cost for the rewards that the jump may give. Speaking of opportunity costs…

Risks: the true meaning of choices and trade-offs

I’d like to emphasize the importance of having varying meaningful gameplay consequences actually be choices. While it is important for the player to know exactly what the direct consequences of their actions are, it is essential that there are variables that the player cannot influence with the choice they are making. This creates a trade-off, an opportunity cost, a risk. For example, in a role playing game a player might save their health potion for a boss fight but risk dying during the encounters beforehand. In a first person shooter game, the player might forego aiming for the head and risk the slower time-to-kill for a higher chance of even hitting the enemy. In both these situations the player is not entirely sure of the outcome - if the player has total control over the outcome of a situation, the edge is taken off.

Taking a step back, a choice is something the system offers the player. However, what is very important is how the player interacts with this choice. The aspects that define how a player interacts with meaningful choice are the players’ knowledge and execution. In every game there is a clear build-up of knowledge and execution skills as the player progresses. This goes back to the difficulty curve. If you introduce a challenge without first teaching the player the relevant knowledge or ensuring that the player has the correct level of execution to clear the challenge, frustration will arise. A meaningful choice has varying meaningful consequences, but if the player is not aware of these then it might as well not be a meaningful choice. The knowledge to understand the consequences of your actions and the execution to act on it. Understanding these two factors helps us tune our choices to create an optimal playing experience - something fun and rewarding! (Side note: there are some aspects that differ between most PvE and PvP games, such as PvP games’ gameplay largely revolving around the concept of yomi, but the core of knowledge and execution always sticks.)

Example:

Angry Birds was such a hit partially because it creates a risk in every interaction the player makes. As the player aims their bird, it is extremely hard to get the exact throw that they want - the execution is too precise to consistently give the ideal outcome in human hands. On top of that, the player will never know exactly how the bird will bounce and interact with the various entities. They never have complete control. While technically these are both surmountable, it is effectively impossible for a human. This adds a risk - an element of near randomness, however one that is clearly communicated and within the players’ control.

Knowledge

Knowledge is how much the player knows about the game’s world; its systems and rules. As the player learns more about how the world works, they should be rewarded for their efforts. The player is gradually introduced to new variables as they continually expand on their knowledge, allowing players to start off with limited yet meaningful choices. As the game slowly ramps the amount of variables up, ideally while keeping the core mechanics in-tact and consistently important, the player can adapt their perspective and use it to dissect new information. In situations in which the player feels like they have limited information on new concepts, they can rely on their previous experience to deduce a logical and working solution, thus the importance of consistent core mechanics.

However, not all games curve their knowledge based on introducing new elements. Many fighting games have depth based on interactions between player characters rooted in minor differences in ‘frame data’ and ‘hitbox data’ (timings of actions on a frame-by-frame basis and where certain moves can hit the opponent or are vulnerable, respectively), and the player discovering how extremely specific interactions play out is a huge part of mastery of fighting games. Due to the amount of variables at play, identical situations are rare and the minor differences in situations get magnified. A game like Fortnite is very similar - the large amount of variables create an experience in which the player can keep growing their knowledge without the game introducing new elements. As for a non-PvP game example of a game depth increasing without relying on new information, Tetris is a different game for someone optimizing block layouts and being able to recognize patterns as opposed to a new player who simply follows their gut instinct - the game greatly rewards knowledge without relying on introducing new information. The point being; one way to test the player is to have them learn new information, the other way is to test how the player thinks about the game. Asking more from your players by introducing challenges that force them to optimize the system by reconsidering the choices they make will give players satisfaction - sometimes beyond what new options would give, as they re-contextualized the game themselves, relying only on their wits. Designing growth in a way that counteracts functional fixedness is the difference between a cool mechanic and an interesting experience.

Example:

Rayman Legends often follows a formula where a concept is introduced in a safe environment, then another concept is introduced in a safe environment, after which they let the player experience both mixed together. It is important to note that these concepts get introduced in a place where the player is not punished harshly for failure. When something new gets introduced and the player is forced to react to it before they understand they are aware of the choice and/or understand the meaningful outcomes, failure feels unfair. This loops back to the awareness aspect of meaningful choice. Once the player has all the tools to understand the situation, the combination of these aspects introduces a new perspective and forces the player to re-contextualize what they have just learned.

The way knowledge is tested in a fun way usually involves making the player think on the fly. Rayman Legends levels scroll, revealing the next parts of the level slowly, meaning the player can’t prepare. A game like Fire Emblem, a war game, will allow the player to plan a skirmish extensively, then spawn unexpected enemy reinforcements during gameplay. This forces the player to understand the mechanics well enough to adapt on the fly, and if the mechanics have been introduced before (in this case: reinforcements might spawn, the enemies are all recognizable), is the key to turning a knowledge test from a quiz to fun gameplay.

An important thing to consider when thinking about knowledge and how it plays into your choices and difficulty curve is to, once again, stick to a simple core mechanic and build upon that. However, a single core mechanic is oftentimes simplistic, which means that having multiple simple core mechanics contributes to a more well-rounded overall experience. Megaman has a firing system, but also a power-up system which are tied together by a resource management system. Individually these are very easy to understand. However, as the player gets introduced to more complex situations, the options available to the player by these mechanics will not only individually be considered, but also in the context of other mechanics.

A final aspect to keep in mind when building on the amount of information in the world is to create ‘levers’ that are clearly defined and universal to make new concepts easy to introduce as well as creating consistency, preventing you from designing one-off mechanics. For example, a role playing game skill can have a damage, range, cooldown, and mana cost. Having these levers predefined allows you to tweak more easily and gives you more room to create mechanics that interact with these attributes in understandable and fun ways!

Execution

Execution is an integral part of any game. Similarly to how your body is your mind’s interface to interact with the world, so is a controller your interface to interact with the game’s world. While mimetic interfaces do well, many games still stick with the classic controller setup (with minor variations). As such, execution will always be a barrier of entry. While the specifics of UI design and designing for controls are closely related to combat systems, they are the form and form follows function. Rather, I want to look at the way the designer can use execution challenges to enhance the way users interact with conflict.

The most popular example of execution playing into meaningful choice is the headshot. While the area to target is smaller and subject to movement more than the center of the opponent’s player avatar (through techniques such as crouching, but even simple turning, since heads often protrude forwards), when the target is hit the damage is amplified significantly. The knowledge is relatively easy to gain - games that leverage widely known concepts are usually easy to pick-up, as has been seen since the Game & Watch days in which manuals were absent and every game was based on something well-known like cooking or fishing. However the factor that prevents all high-level FPS games from being composed of purely headshots is the execution barrier. While the execution barrier can be a very frustrating experience, the satisfaction of succeeding is nearly impossible to match; once players do get that headshot, the fulfillment is palpable.

Another example: fighting games. Sirlin argues that fighting games are practically double-blind due to a human’s limited reaction time. This, too, capitalizes on the execution barrier. Platformers often steadily ask their players to execute more and more difficult acrobatic actions as the game progresses - all to keep the player engaged and make the execution aspect of a choice be more engaging.

Execution, however, is a much finer line to tread when balancing for meaningful choices. Just as it can be frustrating to not be able to translate your thoughts into actions in real life, so too can it be frustrating to not be able to translate your thoughts into actions in a game. Introducing execution barriers keeps the player engaged. Giving willing players room to push their interface (the player avatar) to their fullest potential is a great way to introduce depth and allow challenges (and the satisfaction that comes with overcoming those). However, due to nature of execution, every single player will have a different execution level and personal limitations - it can be hard to account for all of these when creating an engaging experience - hence making increased difficulty challenges fall within the skillset of the core experiences is often advisable, whether that is aiming in shooters or timing your jump in platformers.

Example:
While headshots are probably one of the most iconic examples available to demonstrate the power of meaningful choice in execution, one has to only look at the ever-popular endless runner. Endless runner-style games are often defined by forcing the player into split-second decisions where they have to weigh the execution related to the choice - frequently there is an easier-but-less rewarding option that cannot repeatedly be taken should the player want to win. On the other hand, there is the harder-but-more rewarding option. This still gives the player the reward of completing a challenge without forcing the player into the harder execution aspects if undesirable - it allows the player to mold the difficulty to fit their desire.

Designing a power fantasy

The thing that will emotionally define the gameplay experience for the player will be power fantasy. What is the player building towards by mastering the game’s system? Do they want to be a demon slayer constantly switching weapons to stylishly defeat enemies a la Devil May Cry? Or is it to have fun with your friends and family playing various simple games a la Wii Sports? Defining your end-goal also defines the essence of the game, ranging from the gameplay mechanics to the story; being a demon slayer in 1000 BCE is a different feeling than being one in an alternative cyberpunk reality.

Based on this power fantasy, the game takes form. The build-up to this power fantasy, however, is key for your difficulty curve. Being strong is fun, but being too strong means there is no challenge. Your choices are less meaningful (whether you press A or B, you’ll win regardless), and knowledge and execution become less relevant. As such, the balance between what makes the experience fun (experiencing the power fantasy) and what makes the experience challenging and fulfilling is important and oftentimes integral to the experience. The player doesn’t really feel like an acrobat if there is too much leeway for jumping. In the same vein, deciding on not only success requirements but also passing requirements is additionally important. In other words: what constitutes beating the level and what constitutes mastery. A skater might simply skate their way to the end of the level, but doing impressive tricks and combinations might reward them with new moves or bragging rights.

Example:
In Castlevania: Symphony of the Night, the player character starts off being extremely powerful. The player gets to experience what it means to be a fully powered vampire, slaying monsters along the way. Soon after, the player character loses all their equipment and abilities. With this, the developers have communicated not only what the power fantasy is and what the player will be building up to, but also instill a desire to return to that state.
 

What is essential in creating a power fantasy is to, once again, decide on meaningful choices. Creating a power fantasy that communicates its core effectively means that the player character will be less adept at other aspects. If the power fantasy is to be a defensive behemoth, staying consistent with the power fantasy might mean that your character doesn’t have that much speed. In these cases, make sure to give the player a way to deal with these weaknesses. Create a play pattern that makes the player compensate for these weaknesses with their strengths and make sure the players feels the risks - and by extension the intended power fantasy.

In conclusion

Once you understand the feeling that you want your player to experience playing your game, the rest of the design is a matter of properly leveraging the varying aspects of a combat system to your advantage. Your combat system can be seen as a series of conflicts that the player experiences and interacts with. These conflicts can be anything from an enemy threatening the player to a hungry pet. This conflict is interacted with by your player making meaningful choices. This meaningful choice is offered by the system and derives its meaning from the players’ awareness and varying unique gameplay consequences. These choices are tuned based on the players’ knowledge and execution - two factors that are balanced to present the player constant risks, creating a difficulty curve, presenting the player a path to mastery.

The end goal of these constant conflicts paired with the conflict resolution is for the player to experience the intended power fantasy. This power fantasy is defined by the ways that you want the player to feel strong, but is also defined by the limitations, weaknesses, and costs needed to create the contrast to let the players experience the highs of the power fantasy.

Finally, while your combat system is an important core aspect of your gameplay, the way you leverage your system is key. The importance lies in the way you design your levels, enemies, content progression, et cetera. Creating a high quality combat system is creating the tools you have available to you when conveying what you want your player to experience. Make sure that these tools serve multiple purposes, achieve what you need, and are efficient at what they do and not confusing to the user.

We all solve conflict constantly in day to day life; turning it into a fun and fulfilling experience is a combat system designer’s pride.

Acknowledgements:

The author would like to extend his gratitude to Jordan McGee for his contributions to this article.