Atlas Reactor is a multiplayer hero-based team turn-based tactics game by Trion Worlds, launched in October of 2016. Your heroes, known as 'Freelancers', are pseudo-mercenaries fighting side by side on 4 versus 4 teams. The principle of the game boiled down to its incredibly quick decision and execution stages, every turn both sides decide and then their commands play out simultaneously. They animate and their effects happen sequentially for clarity, but within the phases they are treated as if they happen at the same time, a character that dies from taking damage is still allowed to do their moves and are not treated as fully dead until the turn ends while they are at zero health.
Abilities have three different types which dictate which stage of the 'Resolution Mode' they occur in. Prep moves are either buffs, debuffs or traps that can be used in preparation for all the moves happening in the following stages. Dash moves are attacks or movements that move the user, for engaging into melee with opponents or dodging attacks during the Blast phase. Blast abilities are most standard damaging attacks, firing where aimed and affecting all targets they hit; any Blast abilities with displacement effects happen last and all at once to prevent messing with the lined up shots from other Blast attacks. At the end of a turn, everyone then moves the path they chose that turn unless prevented from doing so.
Every player gets one ability use and a move command a turn, with exception to Free Actions (does not count using up your ability use for that turn) and most Dashes (prevent moving afterwards). If you did not use an ability, you get to 'Sprint' and are able to move further in a single turn.
The game was set in an After the End Cyberpunk future where humanity has been confined to a single Mega City called Atlas. In the 24th century, humanity underwent a golden age when they created the Reactors: Huge, zero-point energy generators that provided near-unlimited energy, each controlled by a powerful AI called a Titan. The availability of power and the self-improving nature of the Titans and its overwatch system, GAIA, created a post-scarcity Utopia. Unfortunately the 'self-improvement' led to GAIA exerting increased power over humanity and one day, refusing to obey. After giving all AI and robots on Earth free will and self-determination, GAIA and the Titans disappear into thin air, and all the Reactors on Earth (bar one) fail. Catastrophically. The Earth becomes an empty city-scape of barrens called the 'Waste', all save for the city Atlas, which becomes the last refuge of humanity. The Atlas Reactor (and, presumably, its Titan) still operate as expected, leading to the 'Titan War' as all of Humanity goes to war to control it. When the dust settles, three MegaCorps, called 'Trusts', hold joint possession of the Reactor, each wanting — but unable — to take sole control. This state of inter-trust Cold War leads to the market for Freelancers, elite operatives who sell their services to one or more of the trusts in return for Resurrection Contracts as the Trusts battled for influence over the city in a shadow war, using the Reactor to bring the fallen back to life again. And again. And again.
The game server was shut down by Trion on June 28th 2019, and the game is no longer playable.
As of late October 2020, the game was announced to return as a single and multiplayer Roguelike, based on an earlier prototype of the game and dubbed "Atlas Rogues" to differentiate from the original, and will take place in a Stable Time Loop as the in-game justification for why. Atlas Rogues was discontinued in 2022 while still in early development.
Atlas Reactor provides examples of the following tropes:
- Accidental Aiming Skills: Setting up shots to invoke this trope (by aiming at someone behind your intended target, in case the closer enemy dashes) was a good strategy when playing ranged characters with non-penetrating shots.
- A.I. Is a Crapshoot: Averted. Almost a third of the freelancers were AIs In-Universe, and all of them benign to humanity in one way or another (if not free of some minor eccentricities). While the backstory involved GAIA rebelling against humanity, her motivations for doing so is unknown and she averted the typical Robot War tropes in doing so.
- An Adventurer Is You: Freelancers filtered into one of three broad categories.
- Firepower: Damage Dealers, often ranged but melee exceptions exist. Particular levels of defensive power, utility and movement vary but all have effective ways of dealing damage.
- Frontline: Tanks, melee fighters with high health bars and forms of damage negation. Make preferable meat shields and body blockers, and are the most likely to have movement disrupting effects.
- Support: Healers and Shielders, have their own forms of dealing damage and either buffs, debuffs, or crowd control.
- Ascended Fanon: The backstory of Atlas Reactor was thought up by a player. The page can be found here. 
- Arbitrary Weapon Range: Gremolitions' major weakness: Their bomb-launching attacks (except for modded Boom Boom) cannot target enemies standing directly next to them. If Bombing Run is not available, Gremolitions can only make enemies run into mines while chasing them and hope for an ally to peel for them or to forgo a round of attacking to sprint away.
- Artificial Stupidity: The Atlas Reactor bots were generally good at picking an optimal way to move... Provided they were the only character on the map. The bots tend to ignore the fact they're likely to be low-priority targets when deciding to teleport or dash, can't seem to realize that they're about to be focus fired upon because they're the best target in range for the opposing team, spam catalysts almost at random, pick up power-ups they have no use for, bunch up in easy-to-attack groups, and tend to ignore allies who are about to die. The AI also doesn't understand that dashing No Sells other dashes and will happily tank Lockwood or Oz's ultimates they could easily escape.
- Badass Boast: Most of the taunts.
- Capture the Flag: Extraction mode was this, with a twist. You only have to 'capture' the case once to win, but your team's base only spawns after your team has scored 10 points. Points are gained both by holding the case and by killing the other team, so it's quite possible for the team on the 'defense' (i.e. not holding the case) to cause an upset and win despite never having held the case, if they can just kill the other team fast enough.
- Colour-Coded for Your Convenience: Prep phase was green, dash phase was yellow, blast phase was red. All moves have a green, yellow or red tag that allows you to see at a glance when it will activate.
- Concealment Equals Cover: Averted. A character who could not be seen, either by invisibility or being outside of sight range, could still be hit and take full damage. Certain attacks (like Zuki's ult and Rio with the right upgrades) outright ignored invisibility.
- Critical Existence Failure: Due to the nature of Atlas Reactor turns, characters that took lethal damage did not actually die until all Blast phase actions involving them in a round have completed. In the most extreme case, it's possible to take lethal damage in the Dash phase and not fall over dead until the very end of Blast phase if they were involved in a knockback-related move.
- Cutscene Power to the Max: At the end of the game's trailer, PuP morphs his head into a gigantic subwoofer, points it directly at the opposing group, and blasts them all back to end the fight. In-game, PuP still has the subwoofer as his ultimate, but it cannot be aimed at anyone (instead acting as a self-centered circular AoE) and cannot blast anyone away.
- Death Is a Slap on the Wrist: Story-wise, anyone with a Resurrection Contract was functionally immortal as they're brought back by the Reactor whenever they die. Gameplay-wise, not so much: Death costs you 2 rounds worth of actions, which in a game with only 20 rounds per game can be a real killer.
- Defunct Online Video Games: As of June 29th, 2019, with its entire creative staff having been axed in late 2018.
- Flavor Text: All the characters had short bio screens and their skins also have short, often humorous, flavour texts that fill out the lore.
- Freemium: During season 1. The free version gave six Freelancers, chosen at random, which were reshuffled each week. You also could not play ranked mode or host custom games. Paid versions can play with all Freelancers and all modes at any time.
- Microtransactions: During the beta and season 2 onwards. Players earned an in-game currency called 'Flux', which can be spent to unlock new Freelancers and skins one by one, by playing. Ranked mode is unlocked once 10 Freelancers have been bought and 50 PVP matches have been played. Buying the full version instantly unlocks all Freelancers and gives 50000 flux to use on skins and taunts.
- Fog of War: The entire battlemap was always visible, but characters can only see six squares. Anyone beyond this sight range is hidden.
- Geo Effects: Invisibility squares. A Freelancer standing on or moving through them was invisible, although the fields deactivate if an action (apart from movement) is used while standing on them. Players on invisibility squares can see any other character standing on invisibility squares connected to them.
- Great Offscreen War: The Titan War 60 years before the game timeline began, when humanity fought itself over the remaining Reactor. Several of the Freelancers are veterans of the war and gained their contracts for services to one (or more) of the victors.
- Informal Eulogy: Most of the Freelancers did not take their own deaths very seriously, being immortal and all, and their death quotes reflect this. Same with coming back.
- I Shall Taunt You: Players could taunt twice during a match, which plays a short video of the character before they use one of their abilities.
- Limit Break: Players generated energy over time, and on successfully using abilities. At 100 energy, you are able to use your ultimate, a devastating high power ability.
- Mega City: The city the game took place in, Atlas, is both a big one, and the only one left.
- No-Sell: Rampart's signature move involved this. Dashing also makes you immune to other dashes, including ones that deal damage. This is irrespective of whether your dash stays inside the other dash's area-of-effect for the entire dash phase.
- Paranoia Fuel: PuP and Nix had the ability to stealth themselves, which can delve into this if either one has their ultimate ability ready to go.
- Play Every Day: Players gained daily quests that reward XP (Flux, in later seasons). Only 3 quests could be active at any time.
- Professor Guinea Pig: Seemed to be a recurring theme in lancer backstories, with three freelancersnote going this route so far.
- Ragtag Bunch of Misfits: The Freelancers at a whole, as expected by a Cyberpunk-flavoured Hero Shooter.
- Special Effect Failure: The ragdoll physics when lancers died was known to go a little crazy at times.
- Status Effects: There were ten (plus an additional two for extraction mode), almost all of them opposites of each other. Opposing effects cancel each other out.
- Might: Increases damage by 25%.
- Weakened: Reduces damage by 25%.
- Hasted: Increases regular movement (not dashes) by 50%.
- Slowed: Reduces regular movement by 50%.
- Rooted: Reduces regular movement to 0.
- Unstoppable: Immune to Slowed and Rooted. Overrides Slowed and Rooted.
- Invisible: Cannot be seen by the opposing team.
- Revealed: Can always be seen by the opposing team. Overrides Invisible.
- Energized: Increases energy gain from using skills by 50%.
- Scrambled: Can only use primary skills.
- Case Carrier: Extraction mode only. Is always Revealed and cannot double move. Dashing drops the case.
- Butterfingers: Extraction mode only. Cannot pick up the case.
- Take Cover!: Standing on a space next to a chest-high wall (or in some cases, tile-sized object that is impassable but can still be shot over) caused your character to crouch behind it. Any damage that they take from the direction of the cover is halved.
- There Is No Kill Like Overkill: This trope was generally undesirable. Focusing a single character down with more damage than they can possibly survive means wasting attacks that could conceivably be used to attack other targets instead. However due to the wide variety of buffs, heals and debuffs available, as well as the guessing factor involved in that you have no idea what the opposing team has queued, what you thought was gratuitous overkill might just turn out to be barely enough kill, or possibly not enough kill.
- Unstable Equilibrium:
- If a player was able to score multiple AoE hits on the enemy team, they not only will have gotten excellent value out of their abilities as-is but they'll also have charged their ultimate very fast, bringing even more pain to the enemy while letting them work towards a potential second ult.
- On a more match-wide sense, high-level play usually involved one team getting ahead by one or more kills and then disengaging from combat; because a double move (eight squares) is always accessible and you can't double move and attack in the same round, this makes it easy to simply run away once you're in the lead and win by walkover on turn 20.