Warning: this footage contains graphic images

What makes ISIS propaganda so effective, particularly in drawing a seemingly endless stream of recruits from western countries, including many living comfortable lives in North America, Europe and elsewhere?

The answer, according to a study carried out by George Washington University scholar Javier Lesaca, is by ditching the grainy, boring footage of bearded men engaging in lengthy monologues about holy war, which was once the trademark of global jihadis, and instead opting to tap into cultural references western Muslims will find more familiar.

Specifically, ISIS propaganda very often directly replicates scenes from western action movies like American Sniper, and uses graphic first-person footage which mimics the style of violent, popular video games like Grand Theft Auto and Call of Duty.

In one recent case, "Islamic State" produced a gruesome video showing child recruits traversing obstacles and other challenges to earn the "honor" of executing prisoners in a deserted desert complex, in a clip which appeared to draw inspiration from the popular Hunger Games movie series.

Lesaca's study of more than 800 videos illustrated how religious messaging in such videos are kept purposefully sparse, with the focus more on idealizing the "Islamic State" and its "holy war" to the point that its adherents "think of themselves as actors in movies."

"By speaking to its target audience in their own cultural language, they're making terror popular."