2013 role-playing browser game
 stylized as Kingdom Hearts χ[chi], is a Japanese role-playing browser game developed by Square Enix (in collaboration with Disney Interactive Studios), BitGroove and Success, and published by Square Enix for web browsers as the eighth installment in the "Kingdom Hearts" series. Gameplay involves players navigating a customized avatar through Disney-inspired worlds fighting enemies, along with taking down bosses in multiplayer matches in competition with other teams. A version of the game for mobile devices called Kingdom Hearts Unchained χ was released as the ninth installment of the series in Japan in September 2015, and worldwide in 2016. 
In April 2017, "Unchained χ" was rebranded as Kingdom Hearts Union χ[Cross]. It was rebranded once again in June 2020 to Kingdom Hearts Union χ Dark Road with the release of the standalone game Kingdom Hearts Dark Road, the thirteenth installment in the series. "Dark Road" is accessed within "Union χ". It was announced in February 2021 that "Kingdom Hearts Union χ Dark Road" would be shutting down its online features and transitioning into an offline app, starting with "Union χ" in May 2021 and "Dark Road" in August 2022. In August 2024, the game was delisted from all app stores.
"Kingdom Hearts χ" is a prequel to the "Kingdom Hearts" series as a whole, taking place centuries prior. It takes place before the Keyblade War, which established the organization of the "Kingdom Hearts" universe as of the original game. The player assumes the role of a Keyblade wielder who joins one of five factions led by Keyblade Masters fighting for control of the limited light existing in the world. "Union χ" acts as a sequel, retelling part of the story of "Kingdom Hearts χ" before diverging and telling a new story set after its events. The game's plot is connected to "Kingdom Hearts III". The title refers to the χ-blade, a weapon central to the series' story arc. "Kingdom Hearts Dark Road" explores the origins of series antagonist Xehanort and his eventual turn to darkness.
The game was designed as a playing experience that could attract newcomers to the series. Its presentation was compared to that of a fairy tale, as depicting the usual style of the series would have been difficult on the platform. Both Tetsuya Nomura and Yoko Shimomura, veterans from the main series, returned as director and composer respectively. The game received favorable reception from critics. A companion film, "Kingdom Hearts χ Back Cover", was released as part of "Kingdom Hearts HD 2.8 Final Chapter Prologue" in January 2017.
Gameplay.
"Kingdom Hearts χ" is a role-playing video game set in the universe of "Kingdom Hearts" which includes original characters and locations as well as ones from Disney and "Final Fantasy" media properties. Before beginning, players create their own character. Players can customize the gender, hair, and clothing, and choose accessories themed after both Square Enix and Disney universes present in the "Kingdom Hearts" series. Story missions are unlocked by the player. After a certain amount of the available content has been completed, new story missions become available. Players navigate their surroundings by dragging their cursor across the screen. Players navigate different worlds, defeating monsters known as the Heartless. The base game is free to play, with optional microtransactions. Actions use up AP, which can be replenished by either waiting or by using potions, which can be earned or bought. Rare items such as special cards can also be purchased. Alongside the single-player mode, there is a multiplayer mode where teams of players take on Raid Bosses, gigantic Heartless with high HP.
Enemies appear on-screen, and can be engaged by clicking on them. During the player's turn, three cards are randomly drawn from a deck of nine, each resulting in an attack. If the cards' combined strength and attached skills are insufficient to exhaust the enemy's HP, the heartless will counterattack. If the player survives this attack, or continues by spending additional AP, a new turn begins. Upon defeating an enemy, the player earns Lux (which unlocks rewards as it accumulates, but resets weekly), experience points (through which the player advances in level), and Munny (an in-game currency). The player also earns Fragments, cards based on the characters original to the "Kingdom Hearts" series and those from Disney and "Final Fantasy" franchises: the fragments are imbued with different properties depending on the character, such as physical or elemental strikes. Players can level up their cards to improve their attack and defense. Players can strengthen their Keyblade using materials found in each world, and new Keyblades are acquired as the story progresses. Each strengthens different types of cards; for example, Starlight is an all-around Keyblade offering boosts for Power-, Speed- and Magic-type cards, while the "Snow White"-inspired Treasure Trove is Power-type focused.
The mobile version of the game, entitled "Kingdom Hearts Union χ", shares multiple gameplay features with its browser counterpart: the main exception is that this version is tailored for a touch screen. The ability to travel freely between different Disney worlds is also replaced with a stage system. These stages, called quests, are confined to specific areas of specific worlds. Instead of spending AP on individual actions, AP is paid to start a quest, and the player can attack as many enemies, collect as many materials, and open as many chests as he or she can find before defeating a target Heartless. If the player's HP is fully depleted, a choice is offered between forfeiting all progress in the quest or continuing to fight by spending Jewels, a new general-purpose in-game currency. Lux is considered another name for character-leveling experience points. Clothing, hair, and accessories are obtained through Avatar Boards, which each contain an array of nodes on branching pathways. These nodes are unlocked, in set sequences, with Avatar Coins, and may also yield such benefits as increased limits for AP and HP. Cards from the browser version are here replaced by Medals, which are no longer drawn randomly in battle. Instead, each equipped Medal is presented one at a time, and the player is given the choice of attacking one enemy, attacking all enemies (dealing less damage), or using the special attack granted by the Medal (provided the Keyblade's special attack gauges are sufficiently filled). Medals can be combined with matching Medals to improve their special attacks.
Synopsis.
Setting.
"Kingdom Hearts χ" is set in a world called Daybreak Town, hundreds of years prior to the other games in the series. The game begins before the legendary Keyblade War, a conflict sparked due to disputes between Keyblade wielders over the light that created the world, triggering a calamity that reshaped the world into that seen in the rest of the "Kingdom Hearts" series. Prior to the war, a precognizant Keyblade Master known only as the Master of Masters bestows a Book of Prophecies to five of his six apprentices, the Foretellers, before disappearing. The book has the ability to manifest objects and people from the future, and contains an account of future events, from which the five Foretellers learn of a prophecy foretelling the world's destruction. To prevent this, the Foretellers use their books to manifest future worlds and defeat the Heartless infesting them to gather pieces of light, called Lux. Each Foreteller creates and leads their own "Union" themed around their individual animal icon: Unicornis, governed by Ira; Anguis, governed by Invi; Leopardus, governed by Gula; Vulpes, governed by Ava; and Ursus, governed by Aced. The player character, a newly awakened Keyblade wielder, chooses to support one of the Unions and works to ensure the chosen faction's supremacy. The future worlds created by the Book of Prophecies include several worlds introduced in previous series entries, including Dwarf Woodlands (based on "Snow White and the Seven Dwarfs"); Agrabah ("Aladdin"); Wonderland ("Alice in Wonderland"); Olympus Coliseum ("Hercules"); and Beast's Castle ("Beauty and the Beast").
"Kingdom Hearts Union χ" takes place shortly after the events of "Kingdom Hearts χ" in an alternate data worldline, with the player reliving the past to forget the events of the Keyblade War. Due to the Book of Prophecies' loss of power without the Master or Foretellers present, the Keyblade wielders instead visit simulated datascapes based on the various Disney worlds. The game initially repeats the story of the original, dubbed "Unchained χ", but diverges partway through the narrative in a new narrative titled "Union χ". New stories feature the player forming a new team with four other Keyblade wielders, who become friends, while a new set of union leaders must contend with new formless, sentient incarnations of True Darkness. Other major story events that do not involve the player were delivered via game updates, serving to expand on the story of "Kingdom Hearts χ" and continue the narrative after the events of the Keyblade War. All of the worlds from "Kingdom Hearts χ" reappear, alongside returning worlds Castle of Dreams ("Cinderella") and Enchanted Dominion ("Sleeping Beauty"). The game also introduces a new world, Game Central Station ("Wreck-It Ralph").
"Kingdom Hearts Dark Road" is set many years later, beginning 70 years prior to the events of "Kingdom Hearts Birth By Sleep". The story explores the origins of series antagonist Xehanort and his eventual turn to darkness. Scala ad Caelum, a world first seen in "Kingdom Hearts III", acts as a central hub for the characters in the story, while gameplay takes place in the worlds seen in "χ".
The events of all three games are told in a non-linear order; they are presented below chronologically.
"Kingdom Hearts χ".
The player character receives a Keyblade and is given a choice of joining one of five Unions, after which a spirit called a Chirithy explains the player's role of destroying Heartless to collect Lux. Under their Chirithy's direction, the player visits projections of future worlds to carry out their mission. As they continue, Chirithy explains that the Foretellers have learned from the Book of Prophecies about a great battle in which the world will be consumed by darkness. To save the future, the Foretellers use the book's powers to project the future into their era, hoarding Lux to protect the world's light.
The player befriends Ephemer, a Keyblade wielder from a rival Union who wishes to explore the Foretellers' tower in the center of town. The player agrees to help, but Ephemer disappears shortly thereafter. Later, the player meets another wielder from Ephemer's Union named Skuld, who is investigating his disappearance. Exploring the tower, the player and Skuld are caught by Ava, who challenges them to a duel. Upon her defeat, Ava reveals that she has recruited Ephemer into the Dandelions, a group of Keyblade wielders intended to be kept out of the impending war so they may rebuild the world in its aftermath. Ava offers the same invitation to Skuld and the player; Skuld accepts, but the player is uncertain. As time passes, other wielders accuse one another of stealing Lux, and the Foretellers – suspecting one among themselves to be a traitor – begin rallying more wielders to their Unions to bolster their forces for the war.
Seeking a solution, the player, Skuld, and Chirithy find Gula, who believes the only one who can stop the war is the now missing Master of Masters. Ava tracks down the Master's sixth apprentice, Luxu, who vanished to watch the war unfold as per the Master's instructions; when Luxu reveals the true nature of the traitor, Ava attacks him, starting the war as prophesied. Skuld returns to the Dandelions while the player participates in the war alone, battling for as long as they can before collapsing in exhaustion. The war ends with the player as the sole survivor, reuniting with Chirithy, Skuld, and Ephemer before losing consciousness. Sometime later, Chirithy awakens the player and lies to them that the events surrounding the war were all a dream. Unbeknownst to them, Maleficent appears nearby – having traveled back in time after being defeated by Sora and his friends – and makes plans to conquer her world in the past.
"Kingdom Hearts Union χ".
Prior to the Keyblade War, the Master of Masters gives Ava a list of five Keyblade wielders who are to become the new Union leaders; against his orders, she gives a Book of Prophecies to one of them, Brain. Strelitzia, another of the new leaders, attempts to convince the player to join the Dandelions, but she is ambushed