With the exception of custom game modes, matches in Atlas Reactor are 4-on-4, player versus player, turn-based tactics battles. Players can die and respawn indefinitely, but teams win by being the first to 5 kills or by having the most kills after 20 turns (or more for sudden death overtime). Turns are divided into two modes: Decision Mode and Resolution Mode. In the decision mode, players have 20 seconds to coordinate tactics, select actions, and lock them in. In the Resolution Mode, these action resolve over four phases: the Prep phase allows for setting traps, placing shields, and casting buff/debuffs before any movement or damage is done; the Dash phase contains all dodges and charges which may deal damage; the Blast phase is for shooting, blasting, and any other stationary attacks, followed by knock-back attacks, which render the targets unable to move during the Move phase; the Move phase allows for player movement after all other actions with more movement granted to those who used no (or free) actions. Within each phase, all players actions are calculated simultaneously but are rendered sequentially for the player. Therefore, a character seen dying before their action will remain standing until it is completed.