Legends of Runeterra is played 1v1. Each player begins the match with a hand of four playing cardsrandomly selected from their card deck, a 20-health-point nexus, and zero mana. Before the match begins, each player also has the option to trade out any of the first four cards they drew for random different ones from their deck. After this pre-game phase concludes, both players receive a mana gem, one player receives the attack token, and the other receives the defense token. Only the player with the attack token may attack during this round. After each round, the tokens switch between players, and each player draws a random card from their deck. As the number of rounds increases, so too does the number of mana gems each player receives, up to a maximum of 10. At the end of each round, any unused mana becomes spell mana, up to a maximum of three. This mana can only be used to cast spell cards. To play cards, players must spend mana gems. Once played, unit cards may be placed forward once more to either attack or defend with. When attacking, if no opposing card blocks, the card will hit the enemy player's nexus, dealing damage equal to its power stat. If the attacking card is defended against a blocking card, the two cards will clash, dealing their respective damage amounts to one another. Each card also has a health stat. If the damage received is greater than or equal to the health stat of the card, it is destroyed. Striking an enemy nexus with a card deals no damage to the attacking card. The objective of the game is to bring the opponent's nexus to zero health points.
Cards
Legends of Runeterra offers a variety of cards to allow each player to play games in their own unique way. A deck of cards must consist of exactly 40 cards, in which no more than 3 copies of each cards may be added. Additionally, a player can't add more than 6 Champion cards total in a deck. There are three types of cards: Champions, Followers, and Spells. Champion and Follower are lumped together as "units", cards which stay on the field and battle for the players. Champions are generally the most powerful cards in the game, and each has a unique criterion that, once met, will level-up the card to a more powerful version. Followers are normal units that have all the basic functions of a unit card, but do not level-up. Spells are single-use cards that cause special effects when played, and then disappear. Spell cards come in three different "spell speed"; Slow, Fast and Burst. Slow spells can only be cast on an open game state, and can't be used in response to an opponent's move. Fast Spells can also be used in response to a Slow or other Fast spells. Burst Spells on the other hand, can also be used in response to Slow, Fast and other Burst Spells. Additionally, Burst Spells don't consume actions, so multiple Burst Spells can be used in a row, during a single chain. All cards in the game come with a mana cost. The player must spend the amount of mana listed on the card in order to play the card. The maximum amount of mana a player can start the round with is 10. All unit cards in the game have their own Power and Health stats. Power is used to determine the amount of damage dealt to the enemy Nexus or blocking units. When a unit's Health reaches 0, it is destroyed and can no longer be used unless it is revived or recovered by an effect.
Development
Riot's employees were fans of collectible card games, and they saw an opportunity to develop one in the League of Legends universe that would fit in with the company's philosophy of "building a game for core gamers who really want to go deep into a genre." Riot brought in a group of professional players in to help test out the game before release, at least one of whom would be retained to help design the final game. The game is an outlier in its genre because it does not require players to purchase so-called "blind decks"; this was partly to let the developers change the metagame as they saw fit without worrying about players losing interest if the deck they heavily invested in became less powerful. Riot's goal was to give each set of cards at least ten viable decks. At one point Riot considered not having packs for players to collect, although testers reacted negatively to this. Legends of Runeterra was announced by Riot and entered its first preview on October 15, 2019, coinciding with the tenth anniversary of League of Legends. Eurogamer noted that the timing was unusual, given the position of the genre following the failure of the similar Artifact as well as the waning audience for Blizzard's Hearthstone. Designer Steve Rubin noted, "There definitely was a moment in development when we were seeing Artifact coming out and we were kind of thinking 'Oh, do we rush it out, or do we not?'" Ultimately, Riot moved forward hoping their game's appeal would transcend the state of the CCG market and attract new players with its more generous business model. The initial preview lasted until October 20 and was only available to a small pool of players. A second preview gave players access to the game's Expeditions mode from November 14 to 19. The game entered open beta on January 24, 2020. The full, official launch of the game occurred on April 29, 2020, for both PC and smartphones. The release also brought the first expansion set in the game, Rising Tides.
