[Editor's note: The following contains spoilers for Zack Snyder's Justice League.]
If you took a drink every time someone growled the word "Anti-Life" in Zack Snyder's Justice League, you...probably forgot a good amount of the movie. So let me reassure you: At no point during the film do we get a clear definition of what the Anti-Life Equation actually is. Steppenwolf (Ciaran Hinds) finds it etched into the surface of the Earth. Darkseid (Ray Porter) really wants it. It is, in the big guy's own words, "the key to controlling all life and all will throughout the multiverse." But what is it, specifically?
Well, maybe Darkseid only spoke in vague terms because the comic book history of the Anti-Life Equation is long, complex, and constantly-changing since it first showed up in 1971. The easiest definition is a literal one: The Anti-Life Equation is an ancient, otherworldly mathematical formula that grants the user total control over any sentient race. (In some cases, it can also compel the dead back to life.) The equation was first discovered by a Mother Box inside the mind of a character named Sonny Sumo—tragically absent from Zack Snyder's Justice League—in Forever People #5, written and drawn by the great Jack Kirby. The character Beautiful Dreamer defines "Anti-Life" as: "The very opposite of living! If someone possesses absolute control over you - you're not really alive."
Darkseid became aware of the Anti-Life Equation some time later, after his devious Apokolips emissaries contacted the residents of Mars, most notably J'onn J'onzz, the Martian Manhunter. (Who does appear in Zack Snyder's Justice League, played by Harry Lennix.) Darkseid learned that the Martians believed in the philosophy of a "Life Equation"—the mathematics behind sentient beings' free will—and deduced that a "Life Equation" suggested the existence of an "Anti-Life Equation." The ruler of Apokolips became obsessed with the idea. Throughout the character's comic book history, he's been tied to the equation more than anyone else; his search for it, his use of it, the ways it often destroys him and brings him back.
"You people have given him a vision," the New God known as Metron tells the Martians in Martian Manhunter #33. "The concept of the Anti-Life Equation now drives Darkseid. You have given a name to that for which he has searched."
Grant Morrison, being Grant Morrison, later wrote out the exact equation in the mini-series Seven Soldiers: Mister Miracle. In that specific instance, it looked like this:
loneliness + alienation + fear + despair + self-worth ÷ mockery ÷ condemnation ÷ misunderstanding x guilt x shame x failure x judgment, n=y where y=hope, n=folly, love=lies, life=death, self=dark side
The Darkseid of Zack Snyder's Justice League is a little less complex than that, searching for a vague concept that would give him total control over everything and everyone, ever.
“I have turned 10,000 worlds to dust looking for Anti-Life," the character says in ZSJL. "Looking for those who robbed me of my glory. I will stride across their bones and bask in the glow of Anti-Life and all of existence shall be mine.”
As for how Anti-Life ended up etched into the surface of Earth, how Darkseid planned to use the "old ways" to get it, and how the Justice League would stop him? Those are unfortunately questions for sequels to Zack Snyder's Justice League that aren't likely to happen. (I would also like to know how Darkseid just, uh, forgot where Earth is?) The filmmaker was clearly setting up future films with Darkseid in mind as the Bigger Big Bad beyond Steppenwolf, with the Anti-Life Equation filling in the Infinity Gauntlet role that Marvel utilized for the Avengers. (Yes, Darkseid came before Thanos in the comics. No yelling!)
Either way, Zack Snyder's Justice League is now available to stream on HBO Max.