Like many other gamers, last week I fired up “No Man’s Sky” again. It is a massively popular and hugely ambitious science-fiction game. In it, you explore a vast galaxy, discover new planets and species, and uncover the mysteries of the universe. Along the way, you encounter three sentient alien species: the scientific Korvax, the martial Vy’keen and the greedy Gek.

The Gek are, in essence, space Jews.

They are a species of short, hooknosed humanoid creatures with shrill voices — and sometimes hats and glasses. And where the Korvax are logical robots and the Vy’keen are proud warriors, the Gek are scheming capitalists.

In short, these characters are yet another retread of a tired, anti-Semitic stereotype given a sci-fi veneer. This is, unfortunately, fairly common for speculative fiction: Stereotyped crypto-Jews have long filled the fantasy and science-fiction genres — from J.K. Rowling’s goblins to Watto in “Star Wars” to the dwarves in “The Hobbit.”

Creating characters that embody anti-Semitic stereotypes is not always an expression of overt bias. Rather, these characters may have been unwittingly developed from caricatures drawn from pervasive stereotypes about Jews. These caricatures have been remixed and ingrained in popular culture over centuries from sources as varied as “The Merchant of Venice,” “Candide” and “Oliver Twist.” In short, these modern creators may have reproduced anti-Semitic caricatures despite, rather than because of, their intentions.

The “greedy Jew” stereotype began in the 11th and 12th centuries as new Jewish communities sprung up across Western Europe. These communities were filled with migrant professionals from the more-advanced economies to the south and east. Their experience, coupled with Jewish cultural, religious and educational traditions, made them very well suited to work at the apex of the developing economies of their new homelands.

Then the church banned Christians from collecting interest on loans to other Christians. Jews, however, were not placed under this restriction. Christians, especially aristocrats, were enthusiastic customers of Jewish moneylenders because loans are a necessary part of any advanced economy. But this created animosity; moneylenders are rarely popular.

Thus, the “greedy Jew” stereotype was born. This was made even worse because in many places, Jews were restricted from many other professions by the discriminatory emerging guild system. And so this stereotype is deeply ironic. Jews were encouraged, then forced, to be moneylenders, and ultimately hated for lending money.

Over the 18th and 19th centuries, Jews fought for and achieved more rights and freedoms, squashing many medieval stereotypes. But economic anti-Semitism remained. In fact, as Europe industrialized and adjusted to a global market economy, the myth of Jewish greed metastasized into the myth of the “Jewish world conspiracy,” wherein Jews are not just greedy, they diabolically control the entire economy.

This economic prejudice was weaponized by the Nazi regime. Propaganda films like “Der ewige Jude (The Eternal Jew)” regularly blamed supposed Jewish manipulation for the economic crisis that gripped Germany.

American anti-Semitism has a long history, too. Though Jews have been part of the United States since the colonial period, the mass migration of Jews to America in the late 19th and early 20th centuries established a new Jewish community that also endured discrimination. And while structural anti-Semitism began to be dismantled in the United States in the generations after World War II, anti-Semitic ideas have persisted in popular culture.

Consider the Star Trek franchise. Star Trek has always embraced political allegory. In the original series, from 1966 to 1969, many of the aliens were stand-ins for real-world Cold War cultures. The Klingons were crypto-Soviets. The Romulans represented the communist Chinese.

When the Cold War ended, the sequel series “Star Trek: The Next Generation” needed a new set of villainous aliens. Enter the Ferengi: short humanoids with prominent ears and noses and sharp teeth. Ferengi men wear distinctive head coverings, and their women are rarely seen. (Ferengi culture is deeply misogynistic and patriarchal.) And more, they are extremely legalistic — their marriages are conducted by business contract, and they have a set of 285 rules that govern their lives.

Above all else, the Ferengi are defined by their greed.

They are the Trek universe’s hyper-capitalists, and their 285 Rules of Acquisition include such classics as: “Once you have their money, you never give it back” (Rule One); “Greed is eternal” (Rule 10); “A contract is a contract is a contract . . . but only between Ferengi” (Rule 17); and “War is good for business” (Rule 34). Taken together, they represent a culture that is not only viciously avaricious but supremely amoral and deeply insular.

To make matters perhaps even worse, many of the actors hired to portray featured Ferengi characters — Armin Shimerman, Aron Eisenberg and Max Grodénchik (who played Quark, Nog and Rom, respectively, on “Star Trek: Deep Space 9”) — are of Jewish descent. The creators of the Ferengi made characters who look and behave like the Jews in the worst of Nazi or early-20th-century American propaganda.

Whether intentional or not, the Gek in “No Man’s Sky” follow this tradition.

This is a profound problem for an otherwise stunning game — and for all authors of speculative fiction. It should stand as a warning to other creators of fantastical worlds. Because even though they may not intend to create worlds populated with stereotypes, they grew up in a world filled with them. It is easy to see how this could happen: When content creators need a species of greedy traders, maybe they are more inclined to make them short. And bespectacled. And maybe give them shrill voices and big noses.

This is a land mine placed by society. Authors or designers may not intend to step on it, but they need to be aware of it and do better. Creators of fantastical worlds need to familiarize themselves with the hateful prejudices and stereotypes that exist in the world and investigate their personal implicit biases — so that they do not end up simply replicating them.