The implementation of online multiplayer both proved challenging due to the team's inexperience, and required a comprehensive story rewrite to recast the protagonist as a player-created avatar.

[1][2] Working from the home hub of New Los Angeles (NLA), the avatar explores the five continents of the open world planet Mira alongside a party of companions.

[1] The avatar can adopt different roles within BLADE, each of which grants different advantages; Pathfinders open up new locations, Interceptors defend research teams from hostile lifeforms, Harriers actively seek hostile lifeforms, including powerful monsters called Tyrants; Reclaimers retrieve wreckage from the White Whale, Curators explore new locations and collect data for BLADE, Prospectors collect rare resources, Outfitters develop gear, and Mediators resolve conflicts among NLA's people.

[3] The avatar initially explores Mira on foot, but gains access to the transformable Skell mechs during the later half of the game after completing a specific set of quests.

Squads can take part in "Tasks", time-limited random missions where players collect a set number of resources from Mira's environment.

[9][10][11] After Earth is caught in the crossfire of an alien war, humanity escapes on spaceships — only a few ships make it off the planet, one of them being the White Whale, containing the city New Los Angeles (NLA).

[1][4] The game takes place on Mira, an uncharted world far away from Earth where the White Whale crash-lands: NLA becomes the center of human activity and commerce.

Due to his bitterness against NLA's leaders for abandoning his family on Earth, Lao attempts to betray the White Whale to the Ganglion, but is persuaded otherwise and gives them the information needed to find the Lifehold.

Before dying, Lao reveals from Luxaar's memories that humanity's DNA was designed by their Samaarian ancestors to destroy the Ganglion using a genetic failsafe.

A narration by Lin reveals that Elma visited Earth thirty years before the Ganglion arrived, giving humanity their means of escape.

Xenoblade Chronicles X was developed by Monolith Soft, with company founder Tetsuya Takahashi forming the original concept and serving as the game's executive director.

[17] Xenoblade Chronicles directors Genki Yokota of Nintendo and Koh Kojima of Monolith Soft returning in their original roles.

[22] The battle system was based upon the basic mechanics of that used in Xenoblade Chronicles, but with an increased sense of speed to make it feel more like an action game.

[15] The team initially envisioned the story taking place over several different planets, but this was discarded as stretching out the possible content over several worlds would limit the experience for players.

[30] Allied mecha designs were handled by Takayuki Yanase, who had previously worked on the anime Ghost in the Shell: Arise and Mobile Suit Gundam 00, along with the video game Metal Gear Rising: Revengeance.

[32] Yoko Tsukamoto, an artist for Lord of Vermilion and Xenoblade Chronicles, was brought in to add fantasy elements to the world, while additional designs for enemies native to Mira were created by Takashi Kojo.

Background art design was outsourced to Kusanagi, a company whose previous art-based work included Ni no Kuni: Dominion of the Dark Djinn.

[37] Takahashi created most of the main scenario himself, working on the script alongside Xenoblade Chronicles co-writer Yuichiro Takeda and Gundam series writer Kazuho Hyodo.

[15] Due to the scale and experimental nature of the game, the Monolith Soft team made an effort to move away from the philosophical storylines their company had become known for with previous titles.

[15] The scenario initially had a set main character with their own narrative, but midway through development the online mode was introduced, and the team decided to rework the story to accommodate a player-created avatar.

The "X" designation stands for "cross" in the Japanese release, which stood for both the meeting of different races in the game's story and the interaction of players online during gameplay.

[42] The vocalists included rapper David Whitaker, singers Mika Kobayashi, Yumiko Inoue, Aimee Blackschleger, Cyua, mpi, and Sayulee.

[53] Alongside the game's release, downloadable content (DLC) was made available for purchase, featuring four new characters with accompanying stories split between three quests, and optional data packs to speed loading times.

[58] Following its release, Xenoblade Chronicles X received software updates via download: the first was minor adjustments to in-game text, while the second added Spanish and French subtitles.

[66] Donald Theriault of Nintendo World Report enjoyed the storyline and plot twists, giving special praise to the affinity missions and localization.

[75] Matt Miller of Game Informer enjoyed the scale and tension of opening missions,[71] Thomas Whitehead of Nintendo Life found the narrative both nuanced and deep.

[74] Eurogamer's Simon Parkin praised the writing and overall pacing,[69] while Alex Fuller of RPGamer noted the worldbuilding done through the side quests and environments.

[77] Japanese gaming magazine Famitsu noted pacing issues,[70] and Destructoid's Chris Carter described the story as "serviceable, yet sometimes drawn-out".

[67] Jose Otero of IGN enjoyed the premise and positively compared its structure to an anime, but faulted the presentation and felt the dialogue "fell flat".

[78] Jeff Landa of Electronic Gaming Monthly was fairly negative about the story and characters, faulting the lack of a compelling narrative or the Xeno series' previous philosophical elements.