Xenoblade Chronicles is an action role-playing game developed by Monolith Soft and published by Nintendo for the Wii. Initially released in Japan in 2010, it was later released in the PAL regions in 2011 and in North America in 2012. A port for the New Nintendo 3DS was released in 2015, and a remaster for the Nintendo Switch, titled Xenoblade Chronicles: Definitive Edition, was released in May 2020. Xenoblade Chronicles is the first entry in the Xenoblade Chronicles series, a subseries which forms part of the larger Xeno metaseries. Although it lacks direct narrative connections to previous Xeno games, like them, it incorporates aesthetic and narrative elements from both fantasy and science fiction. The game features navigation through an open world split into zones, side-quests tied to party members' affinity, and a real-time action-based battle system which incorporates Shulk's ability to see brief glimpses of the future.

Xenoblade Chronicles takes place on the frozen bodies of two warring titans, the Bionis and the Mechonis. The people of the Bionis, including the human-like Homs, are at perpetual war with the Mechon, a mechanical race of the Mechonis. Key to the Homs' efforts in fighting against the Mechon is the Monado, a sword said to have once been wielded by the Bionis. During an attack on his colony, the main protagonist Shulk discovers his ability to wield the Monado and sets out on a quest for revenge with his best friend, Reyn, with others joining in as the game progresses.

The concept for Xenoblade Chronicles originated in June 2006, when the game's executive director and lead writer, Tetsuya Takahashi, visualized and constructed a model of two giant titans frozen in place, with people living on their bodies. Development began in 2007 under the title Monado: Beginning of the World, though it was eventually rebranded with its current title to honor Takahashi's previous work on the Xeno series. The script was worked on by Takahashi, anime writer Yuichiro Takeda, and Nintendo writer Yurie Hattori. The music was handled by six different composers, including first-timer and lead composer Manami Kiyota and industry veterans Yoko Shimomura and Yasunori Mitsuda, with the latter also writing the ending theme, "Beyond the Sky".

The game was announced in 2009 under its original title and released in Japan the following year. Despite releasing in Europe and in Oceania, its North American release remained unconfirmed until December 2011, when a fan campaign called Operation Rainfall drew attention to the game. Upon release, the game was critically acclaimed as one of the best recent role-playing games, while its New Nintendo 3DS port was praised for successfully re-creating the game in a portable form. It was particularly praised for its story, which critics called innovative and surprisingly complex, and was commercially successful in both Japan and the West. In the years since its release, it has been considered one of the best video games of all time. A spiritual successor by the same development team for the Wii U, Xenoblade Chronicles X, was released in April 2015. A sequel for the Nintendo Switch, Xenoblade Chronicles 2, was released in December 2017. A third entry, Xenoblade Chronicles 3, was released in July 2022, also on the Nintendo Switch.

Xenoblade Chronicles is an action role-playing video game (RPG), in which the player controls one character out of a party of three using the Wii Remote and Nunchuk or the Classic Controller. The game employs an open world design, where players can freely navigate seamlessly interconnected environments. The game has a day-and-night time cycle, which often affects in-game events, quests, enemy strength, and item availability: for instance, stronger enemy types appear at night. While time flows automatically and a day cycle repeats about every ten minutes in real time, players can adjust the in-game clock to the desired time at any point. Additionally, while the game is about exploration, areas called "Landmarks" aid in traversing the land by serving as warp points that allow the player to instantly return to that point at any time. The game also supports a "save anywhere" feature, where players can save at any point outside of battle. The game has a New Game+ mode, which maintains much of the player's progress from their initial playthrough into future playthroughs.

Exploration, quest completion, and item collection are large parts of the gameplay. The player is encouraged to explore the large environments, which generally allow them to visit whatever can be seen on the horizon. While exploring, the player can take on side quests from various non-player characters that inhabit the game's world, which commonly involve obtaining certain items or killing a certain number of enemy characters. When the necessary requirements are fulfilled, some quests are completed automatically without the player having to return to the quest giver. Item collection plays a role in the game in the form of the "Collectopaedia". Scattered across the game are glowing blue orbs, and upon collecting them, the player is awarded with a random item that they can add to the Collectopaedia; when a certain number are collected, the player is rewarded with new items. Aside from the Collectopaedia, ether crystals can be obtained from fallen enemies or ether crystal deposits, which are used in the "Gem Crafting" mini-game to craft gems that offer various benefits when equipped.

Many in-game systems affect the general flow of gameplay. The "Affinity" system tracks the relationships between characters and locations in the game. "Location Affinity" tracks the interpersonal relationships between the game's named characters and how they get along with one another, as well as a town's general perception of the player's controllable party. Completing quests can change perception of the characters and open up additional story sequences and quests. There is also "Party Affinity", which is the level of affection between each party member and ranges from indifference to love. Affinity between party members can be raised by having them participate in battle together, giving gifts, or using the "Heart-to-Heart" system. "Heart-to-Hearts" are intimate moments between two characters that show more of a character's personality, history, or thoughts, and can be initiated by having a certain level of Affinity between them. The Affinity system affects how characters work together in battle, as well as gem crafting. The game also has an extensive customization system, which includes changing the characters' outfits and weapons. These changes are directly reflected in the game, appearing in the field and during scripted cutscenes.

Xenoblade Chronicles has a real-time action-based battle system, where the player controls the current lead character in real-time, and party members will "auto-attack" when enemies enter their attack radius. Manually input attacks, called "Arts", may also be performed by the player, but in a limited fashion. Battle Arts are only available after a "cooldown" period that occurs after they are used, while character-specific "Talent Arts" become available after enough auto-attacks are executed. Both party members and enemies have a finite amount of health points, and attacks deplete this value. Combat is won when all enemies lose their HP, but is lost if the player character loses all their HP and is unable to be revived. Health may be restored by the player by using healing Arts in battle, and regenerates automatically outside of battle. Winning battles earns the player experience points, which allows the characters to grow stronger as they level up and learn new Arts. Arts for each character must be set by the player on their respective setup, called a "Battle Palette", outside of battle.