Shovel Knight: King of Cards is a downloadable content (DLC) expansion for the 2014 platform game Shovel Knight, developed and published by Yacht Club Games. The player takes control of a dandy named King Knight as he goes on a quest to win a card game and be awarded the title "King of Cards". King Knight attacks enemies by charging towards them, and is flung into the air after making contact with a surface or enemy. Gameplay is similar to the original Shovel Knight, but features shorter levels and several new locations. Aside from the platforming, the player can engage in a card minigame called Joustus where they must strategically place cards on a board to ensure they occupy certain spaces.

Yacht Club Games intended for King of Cards to be the final planned DLC for Shovel Knight, and desired for it to be the most ambitious expansion. After removing the world map in the previous content pack Specter of Torment, Yacht Club Games hoped to make a new one featuring secret levels and stages with a shorter layout. The developers wanted to create a new experience separate from the franchise's typical platforming gameplay, leading them to create the Joustus minigame. The expansion was released alongside the multiplayer fighting game Shovel Knight Showdown. Upon release, King of Cards received generally favorable reviews from critics, who praised the level design and King Knight's characterization, while the Joustus minigame received a mixed response.

Like Shovel Knight, King of Cards is a 2D side-scrolling platform game.^[1][2] Players control King Knight, a dandy on a quest to win a card game called Joustus and be appointed the "King of Cards".^[3][4] King Knight features a different moveset than other Shovel Knight protagonists; he attacks enemies by charging into them, and is flung upwards after charging into a surface or enemy. After he is flung upwards, he spins in a pirouette, and can bounce upon enemies and objects while spinning.^[1][5] King Knight also has access to magical items called Heirlooms, such as a sword that is used to attack enemies or jump higher, a cloak that deflects attacks, and a bubble that allows him to float above the ground.^[5][6] Heirlooms are purchased using Merit Medals, collectables earned by exploring levels and defeating enemies in the Joustus card minigame.^[5]

The levels of King of Cards are shorter than those of other Shovel Knight titles, and are placed around a nonlinear world map that has several routes to progress. Some stages feature hidden exits that lead to extra levels.^[1][3] Members of the Order of No Quarter, the antagonist organization of the original Shovel Knight, wander the world map, and can be defeated in optional boss battles to earn a reward.^[7] In addition to the platforming gameplay, the player can engage in a card minigame called Joustus at pubs located around the world map. In Joustus, players place cards down onto unoccupied spaces on a board, each card having pointed arrows on some of its sides. A placed card can push an adjacent card to an unoccupied space if it has arrows pointing towards that space. The intent of the game is to have the player's cards pushed onto certain spaces marked by gems, while preventing the opponent from having their cards occupy the gem spaces.^[1][3]

Prior to the events of Shovel Knight and Specter of Torment, a card game called Joustus becomes popular across the world, with a tournament offering the title of "King of Cards" to whoever can defeat the three Joustus Judges. King Knight, a pretender wanting the title of king, receives a deck of cards from Specter Knight and begins to work his way through the tournament. King Knight's victories attract the attention of a bard and an airship captain named Cooper, who both seek a Joustus champion. With Cooper's airship, King Knight travels to Pridemoor Keep to battle the first judge, King Pridemoor, gaining supporters along the way. However, due to the rules simply saying that the Joustus judges had to be defeated, King Knight defeats him in battle instead of using cards. Pridemoor offers to help King Knight defeat the remaining judges, and boards Cooper's airship.

As King Knight searches for the next judge, his mother begins showing romantic interest in King Pridemoor, disgusting King Knight. He defeats the second judge before continuing on towards the last. On the outskirts of the final judge's lair, King Knight witnesses a conversation between Specter Knight and two hooded figures. King Knight confronts and defeats the last judge, King Birder, who is revealed to be one of the hooded figures. The other figure appears, identifying herself as an evil spellcaster called the Enchantress; she tells King Knight of her plan to assemble an army of knights called the Order of No Quarter to help her dominate the world. King Knight, Pridemoor, and their allies pursue the Enchantress to the Tower of Fate, where King Knight defeats her in combat. The Enchantress sways King Knight by offering to appoint him as king in Pridemoor's place, and he turns on his allies to join the Order of No Quarter. King Knight ends the Joustus contest and usurps Pridemoor's throne, with his mother and King Pridemoor abandoning him. In a post-credits scene, King Knight finishes renovating Pridemoor Keep, and remarks to himself that he is finally able to enjoy his kingdom. Shovel Knight enters moments later, and both prepare for combat.

As part of the Kickstarter crowdfunding campaign for Shovel Knight back in 2013, Yacht Club Games listed several stretch goals, additional game features added when funding met a certain target. Among the stretch goals were the addition of three downloadable content (DLC) expansions based around boss characters from the original Shovel Knight. The developers held a vote on which bosses would receive their own campaigns, and King Knight was one of the winning characters.^[8]

King of Cards was the final planned expansion to Shovel Knight alongside the multiplayer fighting game Shovel Knight Showdown, and was intended to be the most ambitious entry in the franchise.^[9] After removing the world map in Specter of Torment, Yacht Club Games hoped to make a larger campaign that featured secret levels and stages with a smaller layout.^[8] The new world map was influenced by Super Mario World and has the main progression routes marked by green paths, while hidden levels are marked by red paths inspired by Mario's use of the color to indicate secret areas. To help players find routes to the hidden levels, Yacht Club Games used red objects to lead players to secret exits, and placed each exit in the middle of each stage to prevent players from replaying the entire level to find both the conventional and hidden routes.^[10]

The team reduced the size of the levels in order to differentiate King of Cards from the previous Shovel Knight games, and halved the player's available health. This was because the health system of the previous entries was designed to work with long levels, and reducing available hit points would make the new stages similarly dangerous. Wanting to avoid decreasing the difficulty of bosses to account for the lower health, Yacht Club Games allowed for enemies to drop health power ups for every three hits they received.^[11] The developers were inspired by Wario when designing King Knight, and intended the character to act "like a big guy who throws his weight around."^[9] King Knight's mobility was altered several times, and the final design was compared by the developers to Plague Knight's from Shovel Knight: Plague of Shadows.^[9] The designers described him as an "over the top and decadent dandy"^[12] and decided to center gameplay around expanding King Knight's holdings by gathering treasure and supporters.^[12]

Yacht Club Games decided to add Joustus to fit their intention that King of Cards would be bizarre and comedic, and wanted to make a new experience beyond the franchise's platforming gameplay. They teased its inclusion in Specter of Torment, and drew inspiration from existing card games such as Hive and Triple Triad from Final Fantasy VIII, as well as trading-card games like Magic: The Gathering and Pokémon. Joustus was developed separately to ensure that it could match the scale of the rest of the game, and was introduced as an optional mechanic to avoid detracting from the platforming. The early prototype of Joustus was called Cardurr, and was based around a 3x3 board inspired by Triple Triad.^[13] Special abilities and mechanics for the cards were created inside spreadsheet shared between team members. Yacht Club Games paid specific attention towards the complexity of the abilities, and created several playable mechanics such "Bomb Arrows" which could be used to remove cards from the board, and "Cascade Arrows" which could convert an opponent's card to the player's side. The developers included ways for the player to cheat at Joustus to align with King Knight's characterization as an evil protagonist.^[14]

After creating the mechanics and abilities for Joustus, the developers planned the total number of cards. The final roster of cards features the likenesses of most characters in the Shovel Knight franchise.^[14] The team spent a significant amount of time brainstorming how the player would obtain new cards in-game, at one point designing a collectable item called "Card Juice" that could transform platforming enemies into cards.^[15] The ability to steal cards from defeated opponents was inspired by collectable card games, and required the creation of a unique deck for every hostile character. To balance the card-playing AI that the player would face, the developers constructed the programming to make decisions intending to prolong each game, while allowing it to shift its behaviors to fit the player's skill. The minigame was originally intended to be played at villages located around the world map, though these locations were replaced by smaller pubs called Card Houses.^[15] The game was planned to release on April 9, 2019, but was delayed,^[16] and was later launched for Windows, macOS, Linux, PlayStation 3, PlayStation 4, PlayStation Vita, Wii U, Xbox One, and Nintendo Switch on December 10, 2019.^[17][18][19] A version for Nintendo 3DS was released on December 13.^[20]

According to the review aggregator website Metacritic, King of Cards received "generally favorable reviews".^[21] Some critics felt that the game was a worthy final expansion to Shovel Knight.^[1][4][6] Nintendo Life said that the game was of similar quality to its predecessors,^[1] while Shacknews felt that King of Cards was the most ambitious expansion in the entire franchise.^[4] Despite finding the game inferior to Plague of Shadows and Specter of Torment, USgamer said that King of Cards was still a competent game within the series.^[7]

Reviewers highlighted the shorter levels.^[1][3] Nintendo World Report found the levels unique in how they deviated from the franchise's typical structure while remaining challenging, and liked how they could be finished more quickly. Nintendo Life compared them to Nintendo platforming levels and felt they brought more mechanical diversity.^[1] IGN felt that the levels were well-balanced, and were difficult but not frustrating to play.^[5] Other critics found some of the stages and designs too familiar.^[2][6][23] Destructoid felt that the campaign was hurt by the inclusion of settings from previous games,^[23] an opinion that Easy Allies also held.^[6] GameSpot found the reuse of previous levels and bosses nostalgic, but became uninteresting over time.^[2]

King Knight's characterization and writing received praise.^[2][3][4] Shacknews equated the character to "a bad Renaissance fair actor who's gotten too far into his role,"^[4] and felt that this characterization helped make him into a fun protagonist.^[4] GameSpot liked the inclusion of humor through the writing, and found King Knight to be entertaining.^[2] GameRevolution enjoyed the story, writing that Yacht Club Games had unintentionally created a narrative relevant to modern times through its depiction of an evil and incompetent character rising to power through chance. The reviewer further enjoyed King Knight's character development throughout the game.^[25] While finding King Knight to be less appealing than previous series protagonists, IGN liked the character's story and called him "The Jerry Lawler of Shovel Knight".^[5]

The Joustus minigame received a mixed response. GameSpot found it challenging, stating that it offered a way for players to take a break from the platforming.^[2] Nintendo Life felt Joustus was more than a simple minigame, calling it complex and fun.^[1] Shacknews considered it a bold and interesting inclusion, and made King of Cards stand out from its platforming-focused predecessors.^[4] On the other hand, GameRevolution criticized the Joustus opponents as too easy, and said that the game relied on randomness over skill.^[25] However, Nintendo World Report found Joustus difficult because of how many strategy elements were incorporated.^[3]