Batman and Superman fight mainly because they deeply distrust each other and are manipulated into a showdown, especially in “Batman v Superman: Dawn of Justice.”

Core reasons they fight

  • Batman sees Superman as a potentially unstoppable existential threat after witnessing the destruction in Metropolis during Superman’s battle with Zod, which killed innocent people and shook Bruce Wayne personally.
  • Superman disapproves of Batman’s brutal vigilante methods, including branding criminals, and sees him as dangerous and out of control.
  • Lex Luthor deliberately engineers their conflict by feeding Batman’s paranoia, stoking public fear of Superman, and setting conditions that force Superman to confront Batman.

What happens in “Batman v Superman”

  • Eighteen months after Man of Steel, Bruce has spent years as Batman and now fixates on the idea that if there is even a small chance Superman could turn against humanity, he must be treated as an absolute threat.
  • Luthor steals Kryptonian tech, manipulates events (like the Capitol bombing) to frame Superman as dangerous, and ensures Batman acquires kryptonite and builds armor and weapons specifically to kill Superman.

The forced showdown

  • Lex kidnaps Martha Kent and tells Superman he must kill Batman within an hour to save her, turning a philosophical rivalry into a literal “fight or your mother dies” scenario.
  • Superman goes to Gotham intending to ask for Batman’s help, but Batman is ready for war with kryptonite gas, armor, and a spear, so attempts at talking quickly collapse into a brutal fight.

How the fight ends

  • Thanks to kryptonite, Batman eventually gains the upper hand and is seconds from killing Superman with the spear.
  • Superman pleads “save Martha,” triggering Bruce’s memory of his own mother Martha Wayne and making him realize he has become what he hates, leading him to spare Superman and team up against Luthor’s monster Doomsday.

Bigger picture and comics context

  • Across comics like “The Dark Knight Returns,” their clashes usually come from ideological conflict: Superman as government-backed symbol and Batman as a fiercely independent, ends-justify-the-means vigilante.
  • Many stories show them eventually recognizing each other’s humanity and values, moving from enemies or rivals into uneasy allies and, ultimately, close friends who respect their different approaches.

TL;DR: If you’re asking “why did Batman and Superman fight,” the short answer is: fear, ideology, and Lex Luthor’s manipulation turned two heroes who should have been allies into temporary enemies.

Information gathered from public forums or data available on the internet and portrayed here.