Additional game features include Battle Mode, Versus Mode, Training Mode, and S.T.A.R. Labs, which includes 240 character-specific challenges of varying difficulty. Online multiplayer modes include King of the Hill, a setup that allows up to eight players to spectate a match while waiting for their turn to fight, and Survivor, which carries over the current winner's health bar and character selection over each match. Playing through any of the game modes, including online matches with optional goal objectives, will net the player experience points that may be used to unlock alternate costumes, music, concept art, and other rewards. Synopsis The campaign of Injustice: Gods Among Us was written by NetherRealm Studios in collaboration with DC Comics' writers. Described by NetherRealm as "Story Mode 3.0", the Injustice campaign was approached similarly to Mortal Kombat vs. DC Universe and the 2011 Mortal Kombat reboot through the use of a cinematic narrative versus the traditional ladder-based single-player experience. According to lead designer John Edwards, the plot is meant to rationalize the game's fighting mechanics between characters that would not normally fight one another and explain how Batman can "stand toe-to-toe" with Superman. Writers Justin Gray and Jimmy Palmiotti served as story consultants to ensure that the comic characters kept their proper voices in Injustice. Plot In a parallel universe, the Joker tricks Superman into killing his pregnant wife Lois Lane and detonating a nuclear weapon that destroys Metropolis, killing millions of people. Mad with grief and rage, Superman murders the Joker, quickly losing his moral compass. Five years later, Superman has formed the One Earth Regime to enforce global peace, and rules the Earth as a ruthless dictator, alongside many other heroes and villains, and killing any who oppose him. Batman establishes the Insurgency to oppose Superman's Regime, and the ensuing war between the two factions leaves the Justice League disbanded. In the prime DC universe, the Joker also attempts to destroy Metropolis with a nuke supplied by Lex Luthor, but the villains are foiled by the Justice League. When Batman confronts the Joker, the two are suddenly teleported into the Regime's universe, where they find themselves pursued by Regime forces. Wonder Woman, Aquaman, Green Arrow, and Green Lantern are also teleported there. The last leaves to recharge his power ring and rescues a captive Deathstroke, while having altercations with Cyborg, Raven, Sinestro, and his own Yellow Lantern counterpart, all members of the