Every comic book fan knows at least one version of Superman's origin story, and each reboot brings with it a new explanation for his famous red and blue suit. But whether you believe it's a Kryptonian blanket or ancient El Family armor, the real question fans should be asking is: what does Superman keep in his belt?
It's easy to understand why the question is both painfully obvious and largely unconsidered by all but the most trivia-hungry comic fans. Over the years the true importance of Superman's uniform has been ignored, or even obfuscated by changing designs. Typically seen as a branding or marketing decision, the launch of DC's New 52 saw Superman's outer-underwear and belt completely removed. But after Rebirth, Superman's classic red shorts have returned in the DC Universe, and his shimmering golden belt has returned along with them!
Over the years countless writers and fans have documented every utility belt compartment, every gadget, and even the true origin of Batman's chest logo. Which means it's time for the contents and purpose of the Man of Steel's belt to finally receive the same level of scrutiny. So for the fans who simply MUST know the answer, we're thrilled to offer it--because it may just be the coolest secret in all of superhero comics.
The Joke Answer: Superman's Cash
The first person to ask about Superman's belt while actually being in a position to answer the question, John Byrne decided to address it when he took over the hero in 1986. With Superman: The Man of Steel starting a new age for DC's mascot, it reintroduced several key components of the mythology. That included his homemade Supersuit, and his belt. John Byrne decided to answer the question by revealing the round, polished, golden buckle was secretly hollow... and then used to to deliver a throwaway gag.
When Superman finds a small video drone keeping close behind him (sent by Lex Luthor and attempting to get a clear photograph of his ever-vibrating face), he makes an unorthodox move. Instead of simply destroying the camera or tracking it back to its source, Superman spots a man selling balloons. Purchasing a bunch of them, he then uses the colorful inflatables to obscure the drone's view long enough to snatch it. Luckily he has the cash to purchase the balloons, he reveals, since he always keeps a few spare dollars in his hollow buckle.
It's a fun answer to the question if that's what fans are looking for, or if they still hold Byrne's incarnation of the Man of Steel above all others. However, it's an answer that lacks... punch. After all, with so many years watching Batman plan for any and all possible threats, wouldn't Superman do some planning of his own? Thankfully, the answer to that question is a resounding YES.
The Real Answer: A Kryptonite Ring
There are several reasons fans remember Superman/Batman: The Supergirl from Krypton, since the story from writer Jeph Loeb and artist Michael Turner went to some truly unique and unexpected places. For the purposes of our question, though, it's most significant for bringing Kara Zor-El a.k.a. Supergirl into the DC Universe back in 2004. At first this twist of fate seemed to be a happy one, delivering a family member to Superman. But Batman saw things differently. To him, it meant the arrival of a being with all the powers of Superman, whose loyalties, character, and potential were completely unknown. Which made her--despite Superman's reassurances--the most dangerous person on the planet.
Batman would, as usual, be proven right when Darkseid succeeded in manipulating Supergirl to become one of his Female Furies serving his Apokoliptian throne. So as Batman and Wonder Woman took on Darkseid and the Furies, respectively, it fell to Superman to make Kara see reason... by any means necessary. And when it became clear she would kill him without hesitation, Superman unlocked his belt buckle to use the secret weapon he hoped would never be necessary: a Kryptonite ring.
Even though comic book fans were still years away from flooding Twitter and Reddit with their outraged responses, Loeb knew to address the obvious issue. As Superman unlocks his hollow belt buckle (an act so rare he can't recall the last time he performed it, in an almost guaranteed nod to Byrne's story), he makes a point of describing it as lead-lined, thereby keeping him completely safe and radiation free. While most fans will agree the ring was likely forged by Bruce Wayne--who else would Superman trust with the material in the first place?--Clark's acknowledgment of the ring as his own back-up plan shouldn't be overlooked. Not just anybody can carry the one thing capable of killing them for fifty years without breaking a sweat.
In the end, it all works perfectly to plan: Supergirl and the readers are completely oblivious to the fact that Superman would store anything in his belt in the first place. Enduring the immediate Kryptonite poisoning visible on his arm, Superman delivers a hit Kara is completely unprepared for. The fight is over in one blow, at which point the ring can be stowed safely in its original lead housing. Solving one of comicdom's most obvious but unanswered mysteries in the process.
Comic book fans shouldn't confuse the Kryptonite ring stored in Superman's belt buckle with the similar piece of jewelry wielded by Batman during some of their fistfights (one of the most famous being used when Batman fought a Poison Ivy-controlled Superman in Batman: Hush). In fact, this bit of trivia could be seen as a demonstration of their friendship. With enough Kryptonite on hand to fashion two rings, Superman kept one in his belt in case he ever faced off against a Kryptonian... and gave its mate to Batman, in case he ever became the threat himself. Proving that after so many years as friends, Batman's need to prepare for the worst really did rub off on Superman after all.