The Gap

Often in games you will hear references to the gap. Most frequently in relation to gapclosers as moves that specific characters receive. However, no one ever explicitly states what the gap is. The working definition I have made for the gap is, When one player can attack another without the possibility of reprisal. Generally we see this as a form of range advantage. The first place I came across the term was in the MMO-RPG World of Warcraft. It was used when talking about the interplay between ranged and melee characters.

This is the gap. The ranged character can hit the melee character without fear of being hit in return. This principle crosses several genres though. It is not confined to MMOs. It also makes it presence known in MOBAs, RTS, Fighting games, and even Chess.  This idea is at the center of many of these genres and has many names. Range, gapclosers, escapes, and so on all belong to the same principle.  Some concrete examples are in order. I will be going through quite a few so that people unfamiliar with various genres of games can still follow along.
MOBAs/MMOs:
These two get lumped together since their gameplay is so similar. To pull away the complexity, imagine there is a character with a ranged attack and a character with a melee attack. All other factors being equal, the ranged character can attack and move and be dealing damage to the melee character without taking damage in return. This move is referred to as kiting. This is the work of the Gap. The ranged character never has to do anything additional and will win the fight. He/She can just keep taking shots at the melee character without being afraid of taking incoming damage. For more concrete examples, picture Ashe versus Udyr, or a Frost Mage versus a Warrior. These match-ups show a clear weakness for the melee to get on top of their opponent to do damage provided no external forces exist. More telling is Caitlyn’s dominance during the early game. Just having 100 range on other ad carries allowed her to be a prominent force in the professional scene for quite some time as getting the odd autoattack in without reprisal would eventually force the other adc to go back to base.
Fighting Games:
A major delineation of characters in fighting games is Fireball vs non-Fireball.
https://www.youtube.com/watch?v=eSDYCfHdVwA
In the video, we see that Ryu is able to attack from virtually anywhere on screen and keep Zangief at bay. Zangief has to overcome the Gap in order to attack Ryu. Each matchup has its own Gap. Fighting games have the Gap more than other examples since unlike MMOs, MOBAs, or RTS games there are no external factors that alter the dynamic.
RTS:
In real time strategy games, range is a critical component to a unit’s strength. So many decisions have to account for range. I’ll speak in depth here about Protoss units since I think they have many examples. The Zealot is a fine unit that drops off as the games goes on, not because their damage is poor, but because they just die before they can close the Gap to deal damage. They have an upgrade that lets them Charge up to units and they become a significant threat again. The Stalker has decent damage but its claim to fame in the early game is its range and speed. These attributes let the Stalker have significant control. Stalkers have an upgrade called Blink that allows them to instantly teleport a short distance. This enhances the attributes of the Stalker by ensuring that they can close the Gap on targets of opportunity or flee from bad situations, opening a Gap from the danger.  The Sentry has a basic ability called Forcefield, which creates barriers, either allowing friendlies to escape or trapping enemy units. The Colossus is a pillar of Protoss strategy, and when does it become the crazy death machine? When its range goes from 6 to 9. This means that the Gap the enemy has to overcome to attack it on the ground is enormous, and more importantly, they have to go through all your other units. These are just some simple ones. Think of the various patches in SC2′s history. What did they do early in Wings of Liberty’s lifetime when Zerg were struggling? They buffed Roach range by 1. That meant Roaches made a better concave and couldn’t be kited as easily. They could also hit Photon Cannons from behind building walls. RTS games lean on the Gap to make the units interact in interesting ways.
These are just some simple examples. The Gap exists across the board. But why bother to define it? Can’t we just be happy with the various terminologies that these games have for the Gap and be satisfied? Two reasons jump to mind.  First is the idea of Asymmetry. Asymmetry has some broad meanings and some very specific ones. I’m going to argue in favor of asymmetric multi-player games. Asymmetric balance is incredibly difficult to pull off. Starcraft: Brood War was a phenomenon.  It had three separate races that all managed to be unique and well balanced. Asymmetry is valuable because if executed properly it adds to the dynamism of the game, specifically as a way to capture your initial audience. The Gap is inherent asymmetry. It exists to confer a starting advantage to different pieces, leading to areas where some pieces are strong and other times weak.  In whatever game you are playing, having room to explore and having games play out differently each time keeps people playing. Having your various pieces be strong in different situations gives lots of room to explore. League of Legends and other highly competitive games grow naturally from their fan base. The larger the number of people playing the game, the larger the scene around the game becomes. While asymmetry is not necessary for a good game, or for replay value, it adds a dynamic that symmetrical games can’t hope to have. The initial value of asymmetry is the “hook” that it provides. Letting players experience different match ups help them feel out limitations and strengths naturally.
Symmetrical games tend to feel like Rock, Paper, Scissors to beginners When everyone has access to the same options they feel how far behind the curve they are when they are starting out. This is problem tends to shrink as a player progresses, and even in symmetrical games the emergent asymmetry of the positions are usually the result of attempting to set up an artificial gap. Take a Terran mirror match in Starcraft. This is a symmetrical match up since both players start with the same resources and available strategies. However, as the game progresses, one player goes for Medivacs and another goes for bio backed up by tanks. This emergent asymmetry is a result of the players each trying to get into a position were they have a Gap over their opponent. The dropping player is trying to use his mobile force to stay away from reprisal, hitting in places and leaving before his opponent’s stronger force can react. The Tanking player is trying to set up positions where his tanks can do maximum damage without fear of his opponent being able to get to the tanks due to their massive range and damage.
However, the big reason to discuss the Gap in broad terms is because of how many decisions designers have to make surrounding it. Things that are almost invisible nowadays. Should a ranged character and a melee character do the same amount of damage with their autoattack? How fast should the characters move? Does turning happen instantly or is their some delay? How fast should attacks be? All of these decisions are predicated on the Gap. We expect melee characters to do more damage because they have to first close distance to do damage. We expect melee characters to have higher movement speed so they aren’t as easy to kite. Turing speed is an important aspect or many games because it reduces the effectiveness of kiting. Ghostcrawler and Morello have both talked about the “Arms race” between ranged and melee characters and this is exactly why. Finding a balance point for the Gap is difficult.
All of what I’ve presented should be fairly self-evident. Its just a formalization of a concept that’s been rattling around in the head anyone who plays games. The next bit is different. What is Crowd Control? It is a way to stop an opponent from taking action. The Gap as I defined it is when one player can attack another without the possibility of reprisal. Being stunned or otherwise controlled is an incarnation of the Gap. This is why crowd control is so powerful and difficult to balance. For melee characters it can even function as a traditional gapcloser and let them get right up on their opponent. This is part of what makes crowd control abilities so sought out. If you are behind a stun or root can let you have a moment when your opponent’s advantage is meaningless. CC gives you the option of coming back in situations where you are behind. It also lets you pick off people that are out of position.
The Gap is a core part of modern game design, but how far back does it go? How long have we been playing around the Gap? Well, the Gap is why basketball players tend to be the tallest around. That extra bit of height gives the taller player a zone where he can control the ball and not have the enemy be able to interfere. American Football is all about creating a Gap for wither your Quarterback or your Running Back. You have blockers and attackers. Chess is about setting up inequalities, spaces where you can attack and not suffer reprisals.  The Gap can be seen at work in games throughout history.
One of the keys to understanding design is understanding the Gap. Looking for areas where the Gap is too large or too small. Seeing the space as an area alive with advantage and disadvantage.
Lef