In the past decade Hollywood has given us movies that began life as theme-park rides, board games, magazine articles, and even self-help books. Now get ready for the next wave of tech-flavoured source materials for future blockbusters after studio Warner Bros optioned a high-concept time travel story based on a long-running Reddit thread.

The idea originated when James Irwin, an author and two-time champion on the US TV quiz show Jeopardy from Des Moines, Iowa, attempted to answer the question: "Could I destroy the entire Roman Empire during the reign of Augustus if I traveled back in time with a modern US Marine infantry battalion" on the popular social news and entertainment website. Irwin, who was writing a book titled The Encyclopedia of US Military Actions (Through Facts on File), posted a 350-word short story in the thread chronicling the exploits of the fictitious 35th Marine Expeditionary Unit, which suddenly disappears from modern-day Kabul and reappears on the Tiber River in 23 BC.

The thread became so popular that it found its way on to the Reddit home page, where studio execs found it in 2011 and decided to contact the author with a view of transforming the idea into a movie. Irwin, who by this point had expanded his story to 3,500 words and was beginning to see it critiqued by military experts and historians, wrote a first draft of the project he called Rome, Sweet Rome, himself. On Tuesday, Variety revealed that a new script is now being written by Brian Miller, the screenwriter of 2011 found footage science fiction movie Apollo 18. The new version swaps US marines for members of a US special force unit but maintains the original's essential premise, though Miller did not see Irwin's draft.

"You can definitely tell that the story was something that I dashed out on my lunch hour without doing a lot of research beforehand," Irwin, told popularmechanics.com in 2011. "Any Marine is going to see mistakes in it, and I'm sure if there were Romans around, they'd say the same thing."

Rome, Sweet Rome now has its own Subreddit on the site, suggesting a ready-made audience for the point when the project eventually hits cinemas. Far from being impressed by the original thread's emergence as a pitch for a Hollywood movie, commenters are already hard at work on spin-off concepts. One recent post is headlined: "Alternative history idea: Spanish conquistadors vs American Vikings". A commenter responds: "Holy shit, can we get a badass writer like Cormac McCarthy to write it?"