League of Legends is a team-based, competitive eSport most often played as a matchup between two teams of five. It is considered the premier example of the relatively new genre known as a MOBA (multiplayer online battle arena), but can also be described as a mix of real-time strategy (RTS) and tower defense. In a game of League NPC armies march down lanes from one team’s base toward another, and the five members from each team help push NPC army lines forward in an effort to destroy enemy towers and ultimately their base. The NPC’s mindlessly march toward the mid-points of each lane and fight each other, however the human players have endless ways in which they can leverage strategic advantages by killing NPC’s for gold (exchanged for items), securing neutral objectives, as well as moving around the map defeating enemy players. Games usually last 30-45 minutes.
League of Legends has been one of the most popular PC video games for almost 8 years now. In order to keep the game feeling fresh among its player base, the developers have relied on bimonthly patches to release new champions and items as well as to rebalance/rework existing champions and items. Among the periodic changes that the games’ success undoubtedly relies on, one thing has remained relatively constant: the design and game theory behind the game’s primary map, Summoner’s Rift. The map has received aesthetic and graphical overhauls, as well as the addition/subtraction of some vegetation, however much of the underlying design of the map has remained unchanged as the very dynamic nature of the game hinges on these elements.
Basic Map Design
Summoner’s Rift is characterized by three lanes, each defended by several turrets. Early on in League of Legends first seasons this presented a unique challenge as five players on each team had to find a way to maximize resource allocation across only three lanes. The prevailing solution that emerged was to place a vulnerable (low health, low mobility) mage or assassin in the middle lane, as there is the shortest distance between the safety of the turrets. Top lane is typically where you would find a melee tank or fighter. Bottom lane generally houses a vulnerable ranged marksman as well as a supportive champion to help protect the vulnerable marksman (the support is designed to operate on a lower gold income). The final person is left to extract their gold from the jungle, the space in between the three primary lanes, which is full of neutral monsters and requires constant mobility.
The “jungler” adds a unique tension to the match, as League of Legends has a “fog of war” system; that is, anywhere without ally turrets or minions is blacked out on the map unless vision is established with a vision ward. This means that the players in other lanes have to be constantly aware that the jungler could be anywhere on the map, ready to ambush a lane to establish an advantage. As the META (most effective tactic available) has matured, this allocation of roles has seldom been challenged, even in other MOBA games.
A final fundamental aspect of the map’s design are the large neutral objectives located in the river that divides the map in half. These objectives have gone through various iterations to become the monsters (elemental drakes and Rift Herald/Baron Nashor) they are today, with the ultimate purpose of creating points of contention which would ultimately force team fights. During some seasons after specific patches, League of Legends games have had longer average durations than 30-45 minutes. Games can stall out if people farm (kill NPCs for gold/XP) their lanes too long with little pressure being applied to key areas of the map. Riot Games’ solution was to create central map objectives that result in powerful buffs for the team who secure them.
Figure 1. Summoner’s Rift with graphical overlays highlighting the bases and lanes for each side. The turrets of blue side’s top and middle lanes are denoted with numbers. The top lane’s outer turret is denoted with a white number three, top lane’s inner turret is denoted with a white number two, and top lane’s nexus turret is denoted with a white number 1. The same applies to middle lane however the numbers are orange. The spawn point for champions on the blue side is denoted with a white letter “N”. This is a modified image taken from Simon Ferrari’s 2013 paper titled “From Generative to Conventional Play: MOBA and League of Legends” published by the Digital Gaming Research Association (DiGRA).
Turret Spacing and Map Control
The turret spacing between and among lanes is perhaps the most critical design element on Summoner’s Rift which helps to dictate the tempo of the game. While this may be something that most League of Legends players know on a subconscious level, many may not actively appreciate how something as small as a few millimeters impacts the tempo.
Figure 1 shows Summoner’s Rift with a few graphical overlays to help demonstrate my point. For the purpose of this article I will focus on blue sides’ top and middle lanes, where the turrets are denoted with white and orange numbers respectively. Essentially, the distance between turrets both within and among lanes gets shorter the closer you get to the defending base. This is significant because it becomes easier and easier to defend your remaining turrets as the outer ones are destroyed, as the distance between remaining turrets decreases. This comeback mechanic is built into the design of Summoner’s Rift and can result in games stalling out, allowing the defending team to catch up on gold.
While League of Legends is an incredibly dynamic game with an ever-evolving META, many of the fundamental map design choices that dictate game tempo have remained relatively constant. That being said, Riot Games has shown that they are not afraid to push the envelope; whether that be champions with mobility dynamics that ignore map terrain (think Aurelion Sol and reworked Talon), or their casually referenced development of terrain destruction abilities. We will have to see what the future holds for Summoner’s Rift.