League of Legends (abbreviated LoL) is a multiplayer online battle arena video game developed and published by Riot Games for Microsoft Windows and macOS. The game follows a freemium model and is supported by microtransactions, and was inspired by the Warcraft III: The Frozen Throne mod, Defense of the Ancients.^[1]

In League of Legends, players assume the role of an unseen "summoner" that controls a "champion" with unique abilities and battle against a team of other players or computer-controlled champions. The goal is usually to destroy the opposing team's "Nexus", a structure that lies at the heart of a base protected by defensive structures, although other distinct game modes exist as well. Each League of Legends match is discrete, with all champions starting off fairly weak but increases in strength by accumulating items and experience over the course of the game.^[2] The champions and setting blend a variety of elements, including high fantasy, steampunk, and Lovecraftian horror.

League of Legends was generally well received upon its release in 2009, and has since grown in popularity, with an active and expansive fanbase. By July 2012, League of Legends was the most played PC game in North America and Europe in terms of the number of hours played.^[3] In January 2014, over 67 million people played League of Legends per month, 27 million per day, and over 7.5 million concurrently during peak hours.^[4] League has among the largest footprints of any game in streaming media communities on platforms such as YouTube and Twitch.tv; it routinely ranks first in the most-watched hours.^[5][6] In September 2016, the company estimated that there are over 100 million active players each month.^[7][8] The game's popularity has led it to expand into merchandise, with toys, accessories, apparel, as well as tie-ins to other media through music videos, web series, documentaries, and books.

League of Legends has an active and widespread competitive scene. In North America and Europe, Riot Games organizes the League Championship Series (LCS), located in Los Angeles and the League of Legends European Championship (LEC), located in Berlin, respectively, each of which consist of 10 professional teams.^[9][10] Similar regional competitions exist in China (LPL), South Korea (LCK), Taiwan/Hong Kong/Macau (LMS), and various other regions. These regional competitions culminate with the annual World Championship. The 2017 World Championship had 60 million unique viewers and a total prize pool of over US$4 million.^[11][12] The 2018 Mid-Season Invitational had an overall peak concurrent viewership of 19.8 million, while the finals had an average concurrent viewership of 11 million.^[13]

League of Legends is a 3D, third-person multiplayer online battle arena (MOBA) game.^[2] The game consists of three current running game modes: Summoner's Rift, Twisted Treeline, and Howling Abyss.^[15] Another game mode, The Crystal Scar, has since been removed.^[16] Players compete in matches, lasting anywhere from 20 to 60 minutes on average. In each game mode, teams work together to achieve a victory condition, typically destroying the core building (called the Nexus) in the enemy team's base after bypassing a line of defensive structures called turrets, or towers.

In all game modes, players control characters called champions, chosen or assigned every match, who each have a set of unique abilities.^[17] Champions begin every match at a low level, and then gain experience over the course of the match to achieve a maximum level of 18. Gaining champion levels in matches allows players to unlock their champion's special abilities and augment them in a number of ways unique to each character. If a champion loses all their health, they are defeated but are automatically revived in their base after enough time passes. Players also begin each match with a low amount of gold, and can earn additional gold throughout the match in a variety of ways: by killing non-player characters known as minions and monsters; by killing or helping to kill enemy players; by destroying enemy structures; passively over time; and through unique item interactions or champion abilities. This gold can then be spent throughout the match to buy in-game items that further augment each champion's abilities and gameplay in a variety of ways. Champion experience, gold earned, and items bought are specific to each match and do not carry over to subsequent matches. Thus, all players begin each match on a more-or-less equal footing relative to their opposing team.

Across matches, players also earn rewards that are applied to their account.

Player accounts begin at level one and progress onward with games played.

Player level is separate from character level; both a level 30 account and a level 5 account would begin at character level 1 at the start of a new game.

From 2009–2017, the maximum account level was 30, and as players progressed, they unlocked additional content and abilities.

This system was reworked in November 2017, with the removal of the level 30 limit and removal of a Runes / Masteries system that gave-game bonuses to players based on their account level.^[18] Playing matches and leveling up provides "Blue Essence" (called "Influence Points" (IP) from 2009–2017), a currency that can be used in lieu of "real money" to access certain locked features.

Accounts are given rankings based on the Elo rating system, with proprietary adjustments by Riot Games.^[19] These ratings are used in automated matchmaking to make games with players of comparable skill level on each team.

League of Legends consists of three main maps, or "Fields of Justice." Each has different terrain, objectives as well as varied summoner spells and items. A fourth map, the Crystal Scar, was discontinued.

Summoner's Rift is the most popular map in League of Legends.^[15] On this map type, two teams of five players compete to destroy an enemy building called a Nexus, which is guarded by the enemy team and a number of defensive structures called turrets, or towers.^[20] One nexus is located in each enemy base on opposite sides of the map, in the lower-left and upper-right hand corners. These structures continually create weak non-player characters known as minions, which advance toward the enemy base along three paths: top, middle, and bottom lanes. Players compete to advance these waves of minions into the enemy base, which allows them to destroy enemy structures and ultimately win the match. Between lanes are neutral areas of the map known as the 'jungle', arrayed in four quadrants. A shallow river divides the map between the teams, but doesn't actually impede movement; all champions can wade through it no differently than dry land.

Each team wishes to defend its own structures and destroy the other team's structures.

These include:^[21]

Some objectives are 'neutral', meaning that they will not attack champions who pass by, but champions can choose to fight them if they wish to gain a reward at the cost of having to fight for it.

They include:

Many of the details have changed over time; League is not a static game, with mechanics being both introduced and removed since launch in 2009. For example, the Rift Herald was only added in 2016, and had its abilities reworked in 2017;^[23][22] Dragons gave gold rather than buffs from 2009–2014, and the dragons only became elementally flavored drakes in 2016; jungle monsters have been added and reworked; the length of time it took for inhibitors to respawn was 4 minutes rather than 5 minutes for a time; Baron Nashor gave a stronger buff to the statistics of champions but no buff to minions from 2009–2014; and so on.

In the Twisted Treeline, two teams of three players compete to destroy the opposing team's Nexus, which is guarded enemy Towers.^[24] It is conceptually similar to Summoner's Rift, but smaller to account for three vs. three rather than five vs. five.^[24] Rather than Summoner's Rift 3 lanes of turrets and 3 inhibitors, Twisted Treeline has only 2 lanes and 2 inhibitors, with the jungle in between. The other differences are the addition of two "Altars", control of which grants the occupying team a variety of bonuses, and the replacement of Baron Nashor with Vilemaw, an evil spider deity. Living members of the team that slays Vilemaw are granted a temporary bonus, similar to the one granted by Baron Nashor.

The Howling Abyss is used for "ARAM" (All Random All Mid) matches, and is five vs. five.^[20] The difference between the Abyss and the other maps is that there is only a single narrow lane of turrets and an inhibitor and no neutral jungle area.

Thus, rather than skirmishes and hidden movement, the Abyss focuses exclusively on large team-fights in the sole middle lane.

Players cannot return to their allied base to replenish health and mana or purchase items unless they have been killed.^[24] ARAM was launched as an official mode in September 2013.^[25]

The Crystal Scar was used for Dominion mode, a discontinued game format where teams of five players competed to capture control points and hold those points for the longest possible period of time.^[26] The map consists of a circle with 5 control points.

Each team controls a base known as a fountain, located at the bottom left and right-hand corners of the map.

Each team scores points by capturing and owning more objectives than the other team over time, which is then reduced from the other team's "life" total.

These points count down from an initial score of 200.

The first team to reduce the other team to 0 points wins.

Dominion was launched on September 26, 2011 and was retired on February 22, 2016, although the Crystal Scar is used for certain other rotating formats, such as Ascension.^[27][16]

League of Legends includes several game types players can select.^[2][29]

League of Legends also includes three ways teams may choose what champion they will play for a given match:

There are currently 144 champions in League of Legends as of May 14, 2019.^[30] League divides its champion types up a number of ways. The most salient difference is the type of damage a champion deals; some champions deal largely physical damage, which is resisted by the armor stat, and other champions deal largely magic damage, which is resisted by the magic resistance stat. Some champions deal with a combination of both and can choose which to emphasize; some rare abilities deal 'true' damage which is not mitigable by either armor or magic resistance. Riot Games has classified all champions as one of six types to aid beginners.^[31] Not all champions perfectly fit their type, of course. The official Riot classifications are as follows:

Item choice plays an important role in the above and can shift the style of a champion.

For example, if the champion Jarvan IV purchases all damage items, he functions something like an Assassin; he can kill enemies quickly but dies rapidly himself.

If Jarvan buys all defensive items, he's a Tank focused on disruption and buffing his allies.

Somewhere in-between, he's a Fighter.

In the same way, champions like Morgana, Annie, and Lux can build item sets that are focused on high damage like a Mage, or item sets focused on disrupting enemies and aiding allies like a Support.

Riot Games, starting in 2013, has released a number of special limited-time game modes.

These special modes would usually be accessible for two weeks, then retired.

In 2016, Riot announced that "Rotating Games Mode" would be a recurring event, so that every weekend a previously released game mode would be made accessible again for that weekend.^[34] Game modes include Ultra Rapid Fire (URF) and All Random Ultra Rapid Fire (ARURF), Hexakill (Twisted Treeline), One For All (Summoner's Rift), Nemesis Draft, Nexus Blitz, Nexus Siege, Legend of the Poro King, Doom Bots of Doom, and Hunt of the Blood Moon, Ascension, One For All (Howling Abyss), Hexakill (Summoner's Rift), Black Market Brawlers, Definitely Not Dominion, and Snowdown Showdown.

The Ultra Rapid Fire (URF) mode was originally a 2014 April Fools' Day prank that proved so popular it became a proper rotating game mode; in URF, champion abilities have no resource cost and have their cooldowns reduced by 80%, double the normal cap of 40% that can be attained through items. Additionally, champions have increased movement speed, reduced healing, faster passive gold gain, and faster attacks.^[35][36]

Teamfight Tactics is an auto battler game mode implemented on June 26, 2019.^[37][38] Based on the Dota 2 mod Dota Auto Chess, the mode centers around a battlefield consisting of hexagons, which players may take turns to strategically place champions onto a game board. After champions are placed, a short battle automatically commences, with the outcome - the number of champions killed - determining the health and gold of each player. Once a player's health is completely depleted, they are out of the game, with the last player standing being the winner. Through a feature called Shared Draft, every couple of rounds, players have access to a free arsenal of champions to select from. Players with lower health eventually are given the opportunity to choose their champions first, allowing for better odds for them to recover during a losing game.^[39]

League of Legends is funded through microtransactions using Riot Points (RP), an in-game currency that can be purchased by players in the client store. RP can be used to purchase champions, champion skins, ward skins, summoner icons, emotes, and certain multi-game boosts. An additional currency, Blue Essence (BE) (known as Influence Points from 2009–2017), is earned by playing the game and leveling up. League of Legends is free-to-play and all in-game purchases with a material effect on game-play may be acquired by either RP or BE. The final currency, Orange Essence (OE), can be used to unlock champion skins, ward skins, summoner icons, and emotes via the "Hextech Crafting".

League of Legends takes place in the fictional world of Runeterra. In Runeterra, the champions of League of Legends are a collection of heroes and villains who have a variety of backstories, often related to the political struggles of the various countries of the main continent of Valoran. Additionally, some champions are extraplanar and come from worlds other than Runeterra, but are visiting for their own purposes. These champions sometimes clash with each other, roughly reflected in the gameplay of League of Legends.

The setting has gone through two phases: the "original" setting that was canon from 2009–2014, and the rebooted setting from 2014–present.^[40] The original setting was very focused on justifying the exact mechanics of a game of League in the world of Runeterra. The MOBA predecessor to League, Defense of the Ancients, featured two warring sides with two separate hero rosters; however, in League, any combination of champions was legal to create a team. To explain this, in the original setting, Valoran was functionally ruled by extremely powerful time mages who could intimidate the other nations into compliance with their whims. They created the "Institute of War", also known as the "League of Legends", to resolve disputes and act as something like an international sports league. In these disputes, "Summoners" (a.k.a. the game player) could control any of Runeterra's greatest heroes or villains in their struggles, thus justifying why a team of 5 characters who all hated each other might form. Additionally, these time mages would actually power-down the characters to "level 1" before each match to make things 'fair'; some character's backstories even involved them explicitly having their powers sealed by the Institute of War due to them being too powerful otherwise, such as the demigoddesses Kayle and Morgana. This explained why characters might participate in multiple matches and have to relearn the same skills each time. After a match, a "Judgment" would sometimes be handed down, with the winning Summoners able to give land and privileges to those they favored.

The narrative team at Riot eventually decided this setup was too constraining, and "rebooted" the story behind League of Legends in 2014.^[41] In essence, the original story put too much emphasis on the faceless player stand-in Summoners and the Time Mages of the Institute; "the very idea of all-powerful Summoners made Champions little more than puppets manipulated by godlike powers."^[40] Any interesting champions the Narrative team created were rendered as secondary, mere servants to the Summoners, unable to influence their own destiny. Many champion's lore did not give them reason to join the Institute, such as serial killer fire spirit Brand or void monster Rek'Sai. Riot wished to let champions take the center stage and have stories of their own, pursuing their own unique goals. For example, Riot has since released a plotline about a lost empire in the Shurima desert^[42] and a plotline about a clash between the pirate Gangplank and the pirate-hunter Miss Fortune in the city of Bilgewater,^[43] both of which were driven by the champions of League of Legends, not Summoners. Riot compared this style of narrative to comic book characters and classic literature, where interesting characters can have many adventures over time and not necessarily have all of them make sense in the same continuity.^[40] A side effect of this is "that the game and story aren’t one-to-one copies of each other."^[40]

The world of Runeterra consists of a number of countries and city-states, locked in a web of rivalry, alliance, and conflict.^[44] The two largest and most powerful entities are the states of Demacia and Noxus, who have fought wars in the past, and are in a Cold War-esque state currently, with each seeking to quietly undermine the other. Demacia is inspired by an idealized Medieval European kingdom, while Noxus is reminiscent of the Roman Empire. Demacian champions tend to value themes like chivalry and honor, while Noxus prides itself on vision, might, and guile.^[45][46] Piltover and Zaun are a city-state at the forefront of technology; Piltover, the "respectable" half of the city, has a "steampunk" style, while Zaun, the neglected undercity of Piltover, is a darker vision of the power of technology, engaging in ethically questionable research.^[47] The Freljord is an icy domain riven by a three-way civil war between rival claimant Queens Ashe, Sejuani, and Lissandra.^[48] Bandle City is a peaceful domain of yordles, a race of small humanoids unique to League of Legends. Ionia is an island nation with a strong connection to magic and features champions inspired by monk and ninja archetypes, as well the Vastaya, a race of animal-human hybrid creatures also unique to League of Legends.^[49] Bilgewater is a port town with a pirate theme. The Shadow Isles is an island chain that was magically corrupted, and has become haunted by a malign force known as the "Black Mist" which leeches life and empowers the undead.^[50] Targon is an ancient mountain peak with a Greek mythology theme. Shurima is a recently resurrected empire that was until recently lost to the desert, with a somewhat Egyptian theme.^[51] Icathia is another fallen and abandoned city where Void monsters from another dimension have crossed into Runeterra, with a Lovecraftian theme.^[52]

Of the current maps, Summoner's Rift is set at the Institute of War from the 'original' League storyline; the Twisted Treeline is set in the Shadow Isles;^[53] and the Howling Abyss map is set in the Frejlord.^[25]

The game's developer, Riot Games, was co-founded by Brandon "Ryze" Beck and Marc "Tryndamere" Merrill, who were roommates while they attended the University of Southern California. They partnered with Steve "Guinsoo" Feak, the previous designer of the popular Warcraft III: The Frozen Throne custom map Defense of the Ancients, and Steve "Pendragon" Mescon, the administrator of the former official support base for the map, to develop League of Legends.^[54]

The original inspiration for "DotA" was a 1998 mod for StarCraft created by community member Aeon64 called "Aeon of Strife".^[55] After the release of Warcraft III: Reign of Chaos and its subsequent World Editor in 2002, DotA was created by another modder, Eul. He ported and expanded the "Aeon of Strife" mod to the new engine and named it "Defense of the Ancients". Guinsoo later made DotA Allstars by inserting his own mix of content to "DotA", greatly expanding the number of heroes, added recipes and items, and introduced various gameplay changes. Guinsoo then passed the mod to IceFrog after accepting a job at the newly formed Riot Games.^[56]

The idea of a spiritual successor to Defense of the Ancients was that it would be its own stand-alone game with its own engine, rather than another mod of Warcraft III, began to materialize at the end of 2005. League of Legends was born "when a couple of very active DotA community members believed that the gameplay was so much fun and so innovative that it represented the spawning of a new genre and deserved to be its own professional game with significantly enhanced features and around-game services."^[57]

Riot Games officially opened its office in September 2006, and, as of 2013, has over 1,000 people working on League of Legends.^[58] According to Marc Merrill, when creating the various champions in the game, instead of leaving the champion creation to just a few people, they decided to open up the champion creation process to everyone in the company based on a template where they could vote on which champions made it into the game.

League of Legends was first announced on October 7, 2008. It was in a closed beta from April 10, 2009 to October 22, 2009. It then transitioned to open beta until release.^[59][60]

League of Legends was released on October 27, 2009.^[61] Riot Games self-publishes and operates the game and all of its customer service aspects in North America. Riot Games has signed deals regarding the distribution of League of Legends in Asia, Europe, and North America. By July 2013, the game has been released and was distributed in Australia, the United States, Canada, Europe, Philippines,^[62] and South Korea.

The game is distributed in China by Tencent Inc., the largest Internet value-added services company in China best known for its QQ Instant Messaging client. The game has been distributed to Tencent's growing 300 million Internet user base through its leading QQ Game portal. The deal was one of only a handful of partnerships to bring a U.S.-developed online game directly to China.

In Europe, Riot Games initially signed an international licensing partnership with GOA, the video games department of Orange's Content Division and Europe's largest gaming portal.

On October 13, 2009, GOA and Riot announced that they would start channeling server access for players located in Europe to GOA's dedicated servers.

This partnership did not last; on May 10, 2010, Riot Games announced that they would take over distribution and operation of the game in Europe.

To do so, Riot Games established a European HQ in Dublin.^[63]

On July 16, 2010, Riot Games announced that Garena would publish the game in Southeast Asia.^[64] Additionally, Southeast Asian players had the ability "transfer accounts" to import their progress stored in North American or European servers into the Southeast Asian server. The game has since been distributed by Garena in Taiwan as well.^[65]

In March 2013, Riot Games released a beta version of an OS X client in addition to their Windows client.^[66] The Mac client was since moved out of beta and OS X / macOs players have had full access to League.

Riot has since expanded to many countries, after the initial North America / Europe / Korea / Garena's Southeast Asia launch.

In 2012, a Brazilian and Turkish server were added; in 2013, Latin American and Russian servers; and a beta of a Japanese server was launched in 2016.^{[67][68][69][70]}

League of Legends received generally favorable reviews, according to review aggregator Metacritic.^[71] IGN initially awarded League of Legends an 8 out of 10 in 2009, highlighting an enjoyable game design, inventive champion design with good customization options, and lively visuals. However, the game's confusing launch was criticized: it was felt that the title was released too early, with some features missing and others to be removed. Finally, the reviewer noted that high level players in the game have "little patience for newcomers", though the reviewer believed that matchmaking (not implemented at the time of review) would solve the problem by matching players of similar level together.^[78]

Leah B. Jackson of IGN re-reviewed the game in 2014, changing IGN's score from 8.0 to 9.2.

Jackson hailed the game "as an example of excellence", praising the variety of champions, rewarding progression systems, and fast but intensely strategic team play.^[77] As compared to fellow MOBA games Heroes of Newerth and Dota 2, Mike Minotti of VentureBeat considered League of Legends as the easiest to learn and to have fastest gameplay pace of the three, while the other two feature more complex gameplay mechanics and are considered closer in style to the original DoTA All-Stars.^[79][80] In 2015, the game placed 15th on USgamer's The 15 Best Games Since 2000 list.^[81]

In November 2011, Riot Games stated that League of Legends had accumulated 32.5 million players, 11.5 million of whom play monthly, of which 4.2 million play daily.^[82] Riot said in October 2013, the game had 12 million active daily players and 32 million active monthly players. In January 2014, the game had 27 million active daily players, 7.5 million concurrent players at peak times, and 67 million active monthly players.^[83] Global concurrent users online peaked at over 5 million players as of March 2013.^[70][84]

By March 2012, League of Legends had become the #1 title in Korean PC cafés.^[85][86] League continues to be popular in Korea; it remained the #1 game until the middle of 2016, when Overwatch displaced it, and is still the #2 game (disclaimer: these numbers do not include home playership rates).^[87][88] In July 2012, Xfire released a report stating that League of Legends was the most played PC game in North America and Europe, with 1.3 billion hours logged by players in those regions between July 2011 and June 2012.^[3] League of Legends is also popular in the Philippines, and was the second most played game in internet cafés in the country in June 2013, behind Defense of the Ancients.^[89] In Taiwan, it is estimated that almost five percent of the entire population had played the game by 2016, with almost a million players subscribed on the server.^[90]

As of August 2018, the game has an active user base of over 111 million players.^[91] As of 2018, the game has an annual revenue of $1.4 billion, making it one of the highest-grossing games of 2018, behind Fortnite and Dungeon Fighter Online.^[92]

Lyrics in the 2018 song "Masterpiece" by Swedish musician Basshunter quote lines from League of Legends.^[93]

In 2009, the game won the Reader's Choice award for PC Best Strategy Game in IGN's Best of 2009 Awards,^[94] and the PC Gamers' Choice in GameSpy's Gamers' Choice Awards 2009.^[95] In 2017, the game was nominated for Best Spectator Game in IGN's Best of 2017 Awards.^[96]

League of Legends is one of the largest eSports, with various annual tournaments taking place worldwide.^[119] In terms of eSports professional gaming as of June 2016 2016, League of Legends has had US$$29,203,916 in prize money, 4,083 players, and 1,718 tournaments, compared to Dota 2's US$64,397,286 of prize money, 1,495 players, and 613 tournaments.^[120]

At the collegiate level, Riot Games sponsors play of the game by college teams in the United States and Canada, offering scholarship money to teams that reach their conference playoffs.^[121] Riot organizes their own four regional conferences, but also partners with two NCAA athletic conferences, the Peach Belt Conference and Big Ten Conference, who organize their own conference play based on their existing institutional membership. Additionally, since 2017, the Big Ten has partnered with Riot to provide $35,000 in scholarship funds yearly to each of the Big Ten's 14 member teams and to broadcast play on the conference's own television network, BTN, through 2019.^[122][123] League of Legends has also been apart of traditional international sporting comeptitions, such as being included as one of the six esports demonstration events at the 2018 Asian Games in Indonesia. In it, eight countries participated after qualifying from their respective regional qualification tournaments, with China winning gold.^[124]