Lightning Returns: Final Fantasy XIII is a 2013 action role-playing game developed and published by Square Enix. A sequel to Final Fantasy XIII-2, it concludes the storyline of Final Fantasy XIII and forms part of the Fabula Nova Crystallis subseries. It was released in 2013 in Japan and 2014 in North America and the PAL regions. It was ported to Windows in 2015 and Android and iOS via cloud gaming in 2016 in Japan. Lightning Returns employs a highly revamped version of the gameplay system from the previous two games, with an action-oriented battle system, the ability to customize the player character's outfits, and a time limit the player must extend by completing story missions and side quests.

The game takes place five hundred years after the previous game's ending. Lightning, the main protagonist of the first game and a key character in the second, awakes from a self-imposed hibernation thirteen days before the world's end. The deity Bhunivelze chooses her to save the people of the dying world, including former friends and allies who have developed heavy emotional burdens. As she travels, she learns the truth behind the world's fate and Bhunivelze's true agenda.

The game's development began in May 2012, shortly after the release of the last DLC for XIII-2, and it was revealed in September of that year as part of the Final Fantasy 25th Anniversary Event. The key creative minds and developers from the preceding games returned, and Square Enix's First Production Department created it, with tri-Ace assisting with graphics development. The development team wanted the game to conclude the story of Lightning and the XIII universe, as well as address criticisms leveled at the previous two games.

The game sold 277,000 units in its first week of release in Japan and went on to become the 17th best-selling game of the year, selling over 400,000 copies by the end of 2013. As of May 2014, 800,000 copies have been sold. Critics have given the game mixed reviews: while they mainly praised the game's battle system, opinions on the graphics, time limit, and other aspects of gameplay were varied, and the story and characters were criticized for being weak or poorly developed.

The player controls Lightning through a third-person perspective to interact with people, objects, and enemies throughout the game. The player can also rotate the camera around the character, allowing a 360° view of the surroundings. The world of Lightning Returns, as with Final Fantasy XIII and its sequel XIII-2, is rendered to scale with the character who navigates the world on foot. In one area, the player can use chocobos, a recurring animal in the Final Fantasy series. The player can freely navigate the game's open-world layout, explore towns and country areas, and accept quests from various non-playable characters (NPCs). Lightning can also sprint for limited periods, climb up ladders, and jump freely. The game features three difficulty levels: Easy, Normal, and Hard, the latter of which is unlocked after completing the game. There is also a New Game+ option, which allows players to begin a new game while carrying over their equipment and stats from a previous playthrough. The in-game clock runs continuously during normal navigation, with one in-game day equating to two to three hours in real time on Easy mode and one hour on Normal and Hard modes. The timer starts at seven in-game days but can be extended to thirteen days. The timer stops during cutscenes, conversations, and battles. Lightning can also pause time using an ability called Chronostasis.

Lightning's growth correlates with her quests; her stats are boosted, with the main story quests yielding the biggest boosts. Many side quests are only available at specific times because of the world's real-time structure, which means NPCs are constantly moving and only appear in certain places at a given time. Lightning can also accept quests from the Canvas of Prayers, a post board found in all the main locations. Completing NPC quests rewards Lightning with a portion of Eradia, spiritual energy retrieved when a person's burden is lifted. Every day at 6 A.M. game-time, Lightning is drawn back into the Ark, a location where the in-game clock does not progress. There, Lightning gives her gathered Eradia to a tree called Yggdrasil; if she has enough, the in-game clock is extended by one day. She can also restock on supplies and collect new equipment. Another feature in the game was Outerworld Services, where the players could take photos and share them, along with their personal stats and battle scores, on Facebook and Twitter. The Facebook features were disabled in April 2015. All Outerworld services were terminated in April the following year.

The battle system, called the Style-Change Active Time Battle system, incorporates elements from the first and second XIII games' Active Time Battle (ATB)-based Paradigm systems, and bears similarities to the dressphere system featured in Final Fantasy X-2. Lightning has access to several customizable outfits (garb) with different power sets (plural: schemata; singular: schema). Each garb has its own ATB gauge, and its actions map to the controller's face buttons, eliminating the need for the usual menu-style ATB battle system; this allows Lightning to have limited movement whilst engaged in battle. Most of the garbs and their accessories are either purchasable in the in-game shops or received upon completing quests. Stronger garbs, items, shields and weapons are unlocked in Hard Mode, along with access to more challenging areas and boss battles. Lightning can directly equip three schemata, with additional slots for backup schemata that can be equipped outside battle. She can be equipped with a close-combat weapon (such as a sword and a spear), a shield, and a cosmetic accessory. Each garb's color scheme can be customized using both pre-set and custom colors, with the option to alter both specific and all portions of the schema.

As in the previous game, enemies appear in the open field and can be avoided or engaged. The number of enemies increases at night, as do their strength and ability to deal damage as the game progresses. After defeating all the standard versions of an enemy, the final version appears as a boss. Defeating it yields a high reward and the extinction of the enemy type in a specific area of the game. When Lightning attacks an enemy, or they attack her, the battle begins. If Lightning strikes a monster, they lose a small portion of their health, but if the enemy strikes Lightning first, she loses health. Lightning's ATB meter depletes as she attacks, requiring her to switch to another assigned garb; the depleted garb's meter recharges while not in use. Lightning uses her many swords for short-range melee attacks and magic for long-range ones. She can block and evade enemy attacks with her shield, which can be assigned to any garb. Each enemy has a stagger meter, indicated by a line behind their health bar.