It's an understatement to say that DC Comics’ Superman and Dragon Ball’s Goku are two ridiculously overpowered heroes in their respective universes, but when fighting against Marvel's Thor in a cross-company match for the ages, Supes reveals why Goku would mop the floor with him! Let’s just say rules are rules, especially the ones governing each character’s specific universe.
An unavoidable loss already explained in 2003's crossover titled JLA/Avengers, written by Kurt Busiek and illustrated by the late and great George Perez, the hook of this series is all in the name. Pitting the Justice League of America against the Avengers in a bid to save their respective universes from total and utter annihilation, this popular event saw iconic DC and Marvel characters like Batman, Superman, Captain America, Thor, and more, duke it out in ways that gave fans of both companies something to obsess over.
Part of the bigger Justice League/Avengers battle happening at the time, the brawl in question sees the Mighty Thor face off against The Man of Steel in a way that can only be described as epic. Blasting Thor in the chest with his patented heat vision, Superman is attacked with an electrified Mjolnir, giving way to a supposedly impossible feat: Superman single-handedly holding Thor’s iconic mystical hammer at bay, something that no one on the battlefield — The God of Thunder especially — can fully comprehend. And as all stand in awe at the strength of Superman on full display in front of them, Superman utters a single line that explains everything fans need to know about why he could never beat Goku.
Stopping the full might of Mjolnir with the palm of his hand, Superman says, “Sorry to disappoint, but in my world, it looks like the dials go up to eleven!” a bit that can initially be construed as a fun little one-liner (or Spinal Tap reference) for Supes to utter while tossing Thor to the side. Instead, this quote holds a deeper meaning, specifically in regards to the very nature of these differing Marvel, DC, and Dragon Ball universes and the rules and limitations that shape and mold them into the realities their heroes and villains live and fight in.
Theorizing earlier that each universe has some kind of built-in law of physics in terms of how powerful characters can become, Superman gives the Marvel Universe’s power scale a “10”, with the DC Universe’s cranked to “11,” telling fans through this in-lore explanation why he could never beat Goku: if DC's world goes up to 11, Dragon Ball's bombastic power cap goes to 15 at the absolute least. But make no mistake, Superman is indeed a strong hero, it’s just that the term “powerful” is relevant to the characters inhabiting that particular universe, with Dragon Ball currently sitting at the top of the list with ridiculously overpowered characters like Ultra Ego Vegeta and Ultra Instinct Goku utilizing their transformations of unimaginable strength and skill in ways that always seem to hint at another even more powerful form on the horizon.
To summarize, the most powerful heroes in DC Comics will always out-muscle the most powerful ones from Marvel, and the most powerful hero in DC (Superman) will always lose to Dragon Ball’s most powerful hero (Goku) simply because, at this point, Dragon Ball’s power cap is beyond human comprehension. So while it’s highly unlikely Superman and Goku will ever meet, Big Blue’s words in this crossover will have to act as the definitive reason as to why he could never beat this stronger Saiyan warrior.