Contrary to what broadcast television’s fall schedules might suggest, the revamped trend of using comicbooks as source material for TV shows has been hot for a while — even if the brains behind the networks’ programming slates have a hard time remembering that.

“It’s funny — if you talk to the people at the networks, they constantly forget that ‘The Walking Dead’ is based on a comicbook,” David Goyer, exec producer of NBC’s upcoming “Constantine” says of the hit AMC series. “I mean, constantly. ‘The Walking Dead’ is the most successful show on television, bar network, bar anything. That’s a massive statement.”

That’s because the highly rated zombie apocalypse drama, which is an adaptation of scribe Robert Kirkman’s Image Comics series, doesn’t feel like it came from a one-dimensional medium, argues comicbook author and “Batman: The Animated Series” alum Joe Lansdale — at least not in the stereotypical sense.

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“Real characters with real problems, and things that rise above merely angst, have helped” make “Walking Dead” successful, according to Lansdale, who is also the author of a series of novellas about an everyday crimefighting duo named Hap and Leonard, the basis for a series currently in development at AMC sister network SundanceTV. “You can understand that kind of angst in that kind of world, and there are no super powers. The story is less about the walking dead as it is about the characters having to live in a changed world, and with each other, and how they cope with that. Comics are a great source for television, and certainly this show has proved it. Also, more freedom [of content] is a big part of its success.”

Similarly, “Constantine” and The CW’s midseason procedural “iZombie,” hail from DC Entertainment’s darker Vertigo imprint. Goyer points out that his lead, John Constantine — who was established in Vertigo’s “Hellblazer” series — has appeared in comics alongside the likes of Batman and Superman, even if he doesn’t wear lycra.

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The (potential) success of these edgier, more niche properties should mean greater opportunities for characters beyond the more prosaic figures found in Marvel and DC’s main catalogs, says Reginald Hudlin, a film and television multi-hyphenate and self-proclaimed comicbook lover who penned the Marvel series “Black Panther” from 2005 to 2008. The next step, he says, is diversification in casting as well as in source material.

“Oh there’s no question, and that’s one I plan on taking full advantage of,” jokes Hudlin, who is African-American, before adding that “as this genre matures, you’ve got to look for ways for making yourself unique in the marketplace and one of the ways to do that is to have a person of color as a lead. I think if you have a charismatic star as your lead, audiences have no bias except for things that are entertaining.”