Humanity is on the brink of extinction as robotic monsters known as "Raptures" have wiped out most of human civilization across the world. The relatively few humans left are hiding in a large underground city known as The Ark, surviving on what resources they can scavenge from the surface or make on their own. In an attempt to fight back against the Raptures and reclaim the surface, humans have created Nikke, humanoid androids in their ideal image, carrying weapons capable of destroying the Raptures.
The player is a newly-graduated Commander tasked with leading a small group of Nikke. After a botched mission on the surface forces them to execute a corrupted Nikke, the Commander is thrust into a conspiracy that threatens not only their own survival, but the survival of the remaining humans in the Ark.
The Commander can choose up to five different Nikke to take into battle, balancing their assigned weapons on top of their own strengths and weaknesses against those of the Raptures they will face. Nikke are stuck with their attached weapon, but can equip different gear depending on their class to enhance their base stats.
Battles are done in a cover shooter style, with separate health bars for the Nikke and the cover they are hiding behind. By dragging a finger or stylus across the bottom half of the screen, the player can make their Nikke pop out from cover and automatically fire at whatever enemy the reticle is aiming at, with extra damage for hitting the enemy core with an affinity that they are weak against. Their other teammates will automatically fire at priority targets. The player can order all Nikke to stop firing and get behind cover if they suspect a powerful attack is about to hit, but this is only a temporary solution.
After dealing enough damage, the player fills a Burst meter that allows Nikke to activate a special Burst ability in three stages (as shown by the Nikke having 1-3 in Roman Numerals by their portrait). After activating Bursts 1-3 in order, the player unlocks Full Burst mode, where all Nikke will focus fire on the target designated by the active Nikke for about 10 seconds, delivering greater damage in addition to any buffs provided by the activated Bursts. After this, there will be a cooldown for the Nikke who activated their Burst, ranging from 20-60 seconds, before they can use it again.
Most battle stages fall into one of three modes:
- Destroy: As the name suggests, destroy all enemy Raptures until a Boss comes out to face you, then destroy them to complete the stage. Some stages, a powerful Boss will attack you from the start.
- Defense: Waves of Raptures spawn from the left side of the screen and you must defend the wall on the right side from being breached until the timer ticks down to zero. The wall has 20 HP, but some bigger Raptures do more than 1 damage after crossing the threshold.
- Base: A pseudo-King Of The Hill mode, where Nikkes and Raptures are engaged in a tug-of-war over a large square of territory. Raptures on the ground are able to occupy the base, and your squad must destroy them to increase control over the base. First side to reach 100% control, or the most control when the timer hits zero, wins the stage.
Outside of battle, players can explore a world map in each chapter that displays different enemies that they can fight. There are also hidden Secret Relics that players can collect scattered across most maps. Collecting these relics results in everything from simple flavor text to blueprints that can be used to construct buildings at the Outpost, and collecting a full set of certain relics can give the player a small amount of gems when checking them in at the Command Center.
The titular Nikke are the android girls with guns, formed in mankind's ideal image, which explains why most of them have giant T&A despite providing no tactical advantage (don't think about why some of them look like little girls, that will involve a lot of disturbing questions you don't want to know the answers to). Each Nikke is equipped with one of the following weapons:
- Assault Rifle (AR) - All-around decent weapon that can hit targets at any distance.
- Minigun (MG) - Takes a few seconds to spin up and loses accuracy at long distance, but riddles Raptures with hundreds of bullets before needing to reload.
- Rocket Launcher (RL) - Explosive ordnance that can take out groups of smaller enemies clustered together in a single shot, especially at full charge.
- Shotgun (SG) - Ideal for encounters with close-range enemies, the shotgun trades accuracy for firepower.
- Submachine gun (SMG) - A close-range weapon that is not as powerful but can be quickly reloaded.
- Sniper Rifle (SR) - Weapon that takes time to charge, but can accurately punch through enemies at long range. Unlike other weapons, the reticle zooms in while aiming.
Split between three classes
5 elemental Affinities
Most Nikke have been built by one of three companies (or classified under a fourth, separate faction). This has little affect in-game except as a restriction on which Nikke can be used in the Tribe Tower, or specific upgrades through the Recycling Center at the Outpost.
Owned by a stern woman named Ingrid, Elysion develops Nikke with a focus on security and logistics to maintain order throughout The Ark.
|Counters||Neon, Rapi, Shifty||Ragtag squad of outcasts stuck together with the rookie Commander at the start of the game.|
|Infinity Rail||Brid, Diesel, Soline||Tasked with operating and maintaining mass transit throughout The Ark.|
|The Scouts||Delta, Signal||A recon squad tasked with keeping watch over Rapture movements on the surface.|
|Absolute||Emma, Eunhwa, Vesti||The "absolute" strongest squad that Elysion has produced, tasked with completing highly dangerous missions.|
|Extrinsic||Guillotine, Maiden||A special squad tasked with putting down Irregular Nikke before they harm any humans.|
|A.C.P.U.||Miranda, Poli||Assists the police with maintaining order in The Ark, most people are unaware that these are Nikke.|
|Aegis||Helm, Mast, Anchor||A squad designed for naval combat, with an amphibious warship called the Admire.|
|Perilous Siege||D, K||Nikke Assassins, capable of killing even humans if they are ordered to.|
|Triangle||Privaty||Law enforcement that works directly for the Central Government, with members drawn from the Big Three.|
|Replace||Soldier EG/FA/OW||Mass-produced Nikke used for various missions, considered "replaceable."|
Owned by a bratty yet intelligent girl named Syuen. Missilis produces Nikke that push the boundaries of high-tech research, sometimes into areas of questionable legality or morality.
|Mighty Tools||Centi, Liter||Can build or support the construction of anything from large buildings to small gadgets.|
|Recall & Release||N102 (Anne)||An experimental unit that studies and manipulates Nikke memories.|
|Nepenthe||Epinel||A recreational squad designed to help humans forget about their troubles for a bit.|
|Master Hand||Julia||The Central Government's ceremonial guard, they perform at official functions and try to preserve humanity's music.|
|Exotic||Crow, Jackal||Living at the Outer Rim of The Ark, the squad are ill-tempered Nikke who wear bomb collars to keep them in line.|
|Wardress||Mihara, Yuni||A duo with unique personalities who capture special Raptures alive for Missilis to study.|
|Matis||Drake, Laplace, Maxwell||Missilis' strongest public-facing squad, equipped with the latest tech that the company has.|
|Seraphim||Pepper||Medical support squad tasked with healing both humans and Nikke alike.|
|M.M.R.||Ether||A secretive research unit that experiments on humans and Nikke to create new weapons.|
|Real Kindness||Guilty, Sin, Quency||A trio of ultra-powerful Nikke currently imprisoned underneath the Outpost until they can be rehabilitated.|
|Triangle||Admi||Law enforcement that works directly for the Central Government, with members drawn from the Big Three.|
|Replace||Product 08/12/23||Mass-produced Nikke used for various missions, considered "replaceable."|
Owned by the flamboyant Mustang. Tetra produces Nikke with a focus on entertainment and commerce, proving that Nikke can be just as effective at selling products as they are at shooting enemies.
|Counters||Anis||Ragtag squad of outcasts stuck together with the rookie Commander at the start of the game.|
|Nepenthe||Folkwang||A recreational squad designed to help humans forget about their troubles for a bit.|
|Unlimited||Alice, Ludmilla, Neve||Nikke who live in the far North on the surface, rescuing any lost Nikke and humans (or their bodies) that they find.|
|Prima Donna||Aria, Noise, Volume||Musical superstars with a heavy influence on The Ark's pop culture.|
|Maid For You||Cocoa, Soda, Ade||Nikke who focus on cleaning, cooking, and other maidly duties.|
|Happy Zoo||Biscuit, Nero, Leona||Nikke who take care of animals in The Ark, and can talk to them.|
|Carronades||Belorta, Mica||A heavy explosives squad that clears out Rapture-occupied bases.|
|Talentum||Dolla, Rupee, Yan||A squad that heavily influences most public (and some private) commerce throughout The Ark.|
|Cafe Sweety||Milk, Sugar, Frima||A cafe staffed by Nikke who quietly do odd jobs on the side, from deliveries to fire support.|
|Protocol||Exia, Novel||The official intelligence-gathering arm of the Central Government.|
|Underworld Queen||Sakura, Moran, Rosanna||A secretive Tetra squad that oversees major criminal organizations while hiding their own Nikke nature.|
|Coin Rush||Noir, Blanc, Rouge||Nikke who run a massive "adult entertainment" center in The Ark, including a casino.|
|School Circle||Rei||Part of a Missilis experiment to see if Nikke can continue learning after they've been created.|
|Seraphim||Mary||Medical support squad tasked with healing both humans and Nikke alike.|
|Exotic||Viper||Living at the Outer Rim of The Ark, the squad are ill-tempered Nikke who wear bomb collars to keep them in line.|
|Triangle||Yulha||Law enforcement that works directly for the Central Government, with members drawn from the Big Three.|
|Replace||iDoll Flower/Ocean/Sun||Mass-produced Nikke used for various missions, considered "replaceable."|
Nikke who were created in The Ark long ago but now wander the surface, far from the watchful eyes of the Central Government.
|Pioneer||Rapunzel, Scarlet, Snow White||Survivors of the original Goddess Squad who now wander the surface, fighting for humanity in their own ways.|
|Inherit||Harran, Isabel, Noah, Dorothy||Nikke who want to retake the surface, but not for The Ark. Their true motives are unknown.|
|The Heretics||Modernia, Nihilister||Irregular Nikke who were infected by a virus and fought for the Queen of the Raptures. Later rehabilitated to fight for humanity again.|
Faction created for crossover collaboration events that don't fit in any of the standard Nikke factions.
|Devil Hunters||Makima, Power, Himeno||Members of Public Safety Devil Extermination Special Division 4 (from Chainsaw Man).|
|YoRHa||2B, A2||Military unit of humanoid androids who fight to reclaim the Earth for humanity (from NieR:Automata).|
|Machine Lifeform||Pascal||Robots supposedly incapable of emotion or other human traits, however... (from NieR:Automata)|
Three rarity types: Rare (R), Super Rare (SR) and Super-Special Rare (SSR). Though most of the Nikke are at SSR tier, the commander only has a 4% chance of drawing one per recruitment, and <1% of getting a specific SSR Nikke.
Commanders can collect 50 molds to exchange for a high-tier Nikke, but even that draw does not guarantee a SSR. SSR molds only have up to a 60% chance of drawing an SSR Nikke, and that chance drops to 40% with an SR mold.