This is a post about fighting games and the underlying mechanical systems that make combos possible. This post covers

• the systems required to allow for combos
• several different conceptual approaches to a combo system
• and the macro-level “resource utilization” concepts that are needed for combos to exist.

So what is a combo? Rather simply put, a combo is any sequence of skills or abilities (we’ll improve on this definition at the end of the article, but it’s a good starting point). An important point to make, though, is that this is the videogame definition of a combo; this definition has no bearing on fast food menu combos or the like. In video games, combos are traditionally used to produce a greater effect than the individual moves that go into the combo, whether it’s just increased damage, or the consistency required to pull off a difficult move. As a result of the rather broad definition of a combo, there are a few misconceptions associated with it. One of the more important things to distinguish is the difference between combos and strings.

Strings are a sequence of moves pre-set to be executed in succession, where each part of the string can only be accessed by the execution of the previous part. These are often seen in brawler-type games, like castle crashers, fighting games, and combo-action games. The important difference is that a string is essentially one whole item; if you want to use a move in the middle or at the end of a string, you have to do all the ones before it. A good example is “rekka” attacks, regularly encountered in fighting games (originating from Fei Long’s Rekka-Ken in SF2). The first move only serves to confirm the next two, and cannot easily be used for anything else. The reason this needs to be distinguished from a combo is the fact that combos are all about the player being able to tie together any kind of move or ability, and this example of a string can only be tied into one other move (the next part of the string) until the string is finished. A string can be part of a combo; in fact, that is commonly the case. But a string on its own is not a combo, as it is essentially just one move that requires multiple inputs.

So what makes a combo? Resources. Again, this may seem like a hilariously general statement, but it is only that way to match the broadness of combos themselves. Combos are all about a sequence of moves, and the “sequence” part of that statement is where the concept of resource exchange comes in. The point of using these moves in sequence is to tie difficult-to-execute moves (commonly called “enders“) with versatile moves that give a lot of resources in the form of hitstun, space generation, etc. (commonly called “openers“) to ensure that you can perform a subsequent move successfully. The resources required to use these moves in series differ from game to game, and the potential for combos varies as well; as we’ll see in future examples, combos appear in a great many different games: strategy games, fighting games, card games, action games, etc. all share this concept of resource exchange to enable combo possibilities. As is tradition with this series, what better way to break down a concept than to tie together the similarities between games that share it?

Origin of the Combo

 

Combos in their infancy were actually first introduced by beat ’em ups such as Double Dragon, but these are far different than the dynamic nature of combos as we know them today. Nearly every fighting game in existence has combos in one shape or form. It’s widely attributed to be a “glitch” in Street Fighter 2, where it was possible to execute moves in succession due to the hitstun (the duration of time you are stunned after being hit) of the move being longer in duration than the animation time of the move. Because of the edge cases required to successfully execute a combo: attack data, hitbox shape/size of the attack, hurtbox size/shape of the enemy, combos were extremely difficult to correctly do, and, to be executed consistently, required practice, awareness, and foreknowledge on the stats of your moves and hurtboxes, as well as your enemy’s.

Combos in the present, while generally more involved, still resemble the rudimentary combos of old. Street Fighter, for example, has considerably more “openers” for each character in their cast; the importance of this for fighting games is the ability to *try* and open someone up for a combo. The *try* is important, because even if blocked, the attacking player will have “frame advantage”; essentially, their animation will end before it is possible for the enemy to try and punish them for a blocked move. This is an element of the strategy in the game that encourages combo usage by making it easier to start a combo. Plenty of other fighting games have taken their integration of combos in different directions, and they can show you how malleable the mechanical implementation of a combo can be.

Killer Instinct is a rather famous combo-heavy game, as a large amount of the mechanics unique to Killer Instinct all enable combos in some way shape or form. The framework of normal attack inputs is similar to that of most fighting games, but with greater emphasis on comboing; the system of “double” attacks and “triple” attacks allow players to initially get into combos through easier inputs, “autos”, but still allows more experienced players to truly throw together their own combos from the character’s available kit, “manuals”. In addition to this, the traditional combo framework is extended through the concept of “juggling“; normally if a character is on the ground and stun has worn off, they regain control of their character. In Killer Instinct, if you are knocked into the air, hitstun no longer matters. Until you hit the ground, every subsequent attack on you hits, and from this point on the goal is to keep you in the air for as long as possible by “juggling” you with attacks. This makes combos easier, as you no longer have to worry about hitstun wearing off. In addition to this, Killer Instinct also has literal incarnations of “openers” and “enders“; in KI, a combo does more damage if you end it with an “ender” move, encouraging both complicated combos and ending combos with powerful moves.

KI has a lot of extra mechanics to make combos easier, but there’s an extra mechanic in KI that counterbalances this: combo breakers. Combo breakers are executed by predicting the attacks and attack timing of an enemy comboing you, and reacting to them by pressing the cooresponding attack button when one of their moves would land. If done successfully, it immediately ends the combo and resets the extra damage that would have been gained had the combo been finished with an ender. If done unsuccessfully, it renders you unable to combo-break for 3-4 seconds. Additionally, the attacking enemy who was combo broken can counter-break a combo breaker by predicting an incoming combo breaker and doing a Combo Breaker input. Done successfully, counter-breaking a combo breaker will allow you to continue comboing; this is an important mechanic in the game, as it enables counter-play on both sides. However, counter-breakers cannot be planned for; they can be baited, by using a move that is easy to break and anticipating when your opponent would do so, but they cannot be part of a combo. The moment a combo starts relying on something other than the player’s actions, it ceases to become a combo and becomes a plan. The reason for this distinction is to make sure that combos don’t become too general; it could be said that if you knew how to win from any move in chess, and the previous description of combo is a “sequence of moves”, that could possibly be considered a combo if you considered an opponent’s move a “possible move”. With this new distinction, now the combo is an enclosed system; only acted on by the player’s moves; the enemy’s position and the surrounding area can influence the moves chosen, but they cannot act on the system. With this distinction in mind, we can move on to another fighting game example, Marvel Vs Capcom.

In Marvel Vs Capcom 3, combos are incredibly natural and easy. Moves cancel into one another (interrupting the animation immediately with another move, while the hitstun from the canceled move still applies), so doing moves in succession is easy. The only rules that govern this technique is the hierarchy of moves; medium moves can be canceled into heavy moves, but not vice versa (the order being light, then medium, then heavy, then special, then special moves, then hyper moves. In addition to this, there are a lot of useful resources that enable elaborate combos. Certain moves can put you in a KI-like juggle state, some moves can hit you off the ground after you’ve been knocked down, bounce you off the wall, be unblockable, and you can even call in your other party members to do a move while you are comboing. The other important thing to know about Marvel’s combo system is that it becomes harder to combo over time; damage naturally decays over combo hit count, while hitstun decays over time. Marvel is a naturally awesome game, in the true definition of the word; the massive differences between the power level of moves, along with the crazy garishness of the game’s enders, and the insane combo possibilities makes a game that has a very large amount of depth. Good play in Marvel is characterized by efficient (and commonly difficult) combos, consistent, reactive and malleable gameplay, solid team construction and strategy, and an extremely flexible and adaptive (and offense-based) game plan. It requires a great range of skills, because the potential inherent in the combo-based combat system is incredibly large; Marvel is notorious for having one-touch to death combos be the norm. The amount of theorycrafting and crazy gimmick teams just shows you what is possible within a combat system that allows for such player ingenuity through combos and team comps.

 

Where Marvel’s combos are about maximizing the potential damage of a combo before the damage fall-off becomes severe, Magic the Gathering is about enabling combos in the first place. “Normal” decks usually only have isolated instances of this; when you open the options to all cards, “true combo” decks (decks composed around the entire idea of “getting a combo to go off“) can sometimes be the only viable option. Combo decks in Magic regularly function by turning an otherwise mediocre to unplayable card into a completely broken one.Take, for example, a card that turns what is otherwise a lose condition (a state in the game that eventually results in your immediate loss) into an immediate win condition. In a normal deck, that card isn’t good, especially for that mana cost, and that you usually draw before you could play this card. However, in a deck whose only purpose is to remove cards from your deck, it suddenly becomes an easy way to win. The problem with most of these kind of decks is the fact that once your opponent sees that card, they immediately know what your entire deck is about (most decks like this are named after the appropriate card). This is where the combo part comes in; if you manage to fulfill the game-winning requirement quickly, or perhaps even in the same turn the card is played, your opponent has no options, and you have combo’d them to death. These decks do exist, from the other bad cards that now suddenly combo with this perfectly, to normally good cards whose drawbacks enable this card. Due to the vast range of cards available in Magic, with all their various conditions and requirements, Magic serves as a beautiful example of the previously-mentioned concept of resource exchange.

Combos, as previously explained, are normally sequenced through the exchanging of resources: hitstun for damage, or for time to do a move. In fighting games, there are only 3-5 resources used in comboing: time, damage, spacing (distance between characters), and move size (time is potentially more than 1, depending). However, in Magic, there are so many possible resources that could be used to help combo; for example, in Marvel, you cannot kill a character to do direct damage to another character, or use a large amount of super resources to immediately kill an enemy character. Marvel may be broad, but it’s constrained to the limits of the fighting game system; Magic has no such constraints, and as such, you can exchange anything for anything. Life into red mana, then into damage, then into card draw, then into damage or card draw again, and so on. In this way, comboing can be likened to a series of trades of resources for other resources, usually in an advantageous way. Cards that require little resources for large payout (openers) work well with cards that require a large buy-in for a huge reward (enders); combo-decks are essentially just a construct around getting an extremely ridiculous ender out. In that way, combo-decks are perfectly analogous to Marvel combos. Card combos did not originate from fighting games, but they clearly share that core concept, and several traits that enable it. Many other games have combo related things, and all their constructs of combos still share these traits. Enjoy this list:

• SC2: the combo of Fungal Growth, then Banelings, since Baneling’s main drawback is the difficulty of deploying them correctly
• Rome: Total War: Incendiary Pigs, then Cavalry, as Incendiary Pigs break formations, and Cavalry can capitalize on that well
• Tony Hawk: Pro Skater: literally anything about this entire game. Moves for points, manuals/grinding for chains, with a system that encourages obscenely
  long chains for more points
• DOTA/LoL: moves that stun/impair mobility into moves that are difficult to line up, exchanging that stun resource to compensate for a skillshot’s unreliability
• Bayonetta/DMC: extremely similar to Marvel, moves that juggle into moves that hit in the air repeatedly, capitalizing on the juggle resource by using it to enable a multi-hitting attack that needs someone to stay still

The majority of these are directly combat-based, mostly because combos require an immediate succession of moves, so conceptual combos, like a Zergling/Baneling build in SC2, does not count; it’s a plan, both because of the vague time placement (you don’t “perform” a build order “move”) and because of the potential reaction to enemy play. Directly using zerglings to hold an enemy unit pile still and running banelings into them does count, however. Regardless, it goes to show how universal combos can be.

 

So let’s draw this back together; what is a combo? A combo is any succession of moves linked together by the manipulation of resources, typically for a rewarding payout. That definition sounds grossly mechanical (in addition to being vague), but due to the general nature of combos, it plays less like a definition and more like a checklist. Then again, if combos are so general, what’s the point of trying to define them? Besides the obvious “establishing a solid design vocabulary by discerning and defining traits common to games” being the point of this series and all. Well, every example of a combo given has been in a completely different mechanical gameplay/combat setting. RTS games, MOBAs, fighting games, card games, RPGs; all of their mechanics are different, and yet we can unmistakably identify combos across all of them. THIS is why combos are so important; they are standalone examples of a person’s understanding and grasp of the mechanics of a game at play. To make ANY combo, you have to understand how to combo, what parts in the game go together, and how to correctly utilize them. If someone is capable of making an effective combo in your game, it means that the background mechanics of the game are intuitive enough for them to toy with them. Think of crazy redstone contraptions in Minecraft. All those moving pieces have simple, real-life hardware definitions, and people grasp their mechanics so well they can make awesome things with them. Combos are evidence of the same thing; it takes the same kind of mental process to understand what you would use logic gates for as to understand what resources a move needs to be comboed into.

Combos may seem like straightforward things, but they’re difficult to put together. We’ve talked about all these combos in different games, and it’s because I can understand the underlying systems, and how they link together. Understanding, breaking down, and creating combos are the first step to understanding the entire system of any game; once your eyes are opened to the attributes inherent in every move of a combo, your eyes are opened to the game itself. With that, you can make anything happen; the mark of true understanding is putting something together that the developers didn’t even think was possible. And with combos, that happens all the time.