For most filmmakers working today, the challenges involved in building a successful franchise aren’t likely to come up. It’s hard enough to get one movie made, much less a whole fleet of them. By that same token, navigating today’s industry requires some understanding of the key market forces driving success, and IP is definitely one of them. Come up with an idea that can scale and you might have a shot at real sustainability.

However, this is not the most fertile time to embrace that concept. Warner Bros. Discovery’s “Shazam! Fury of the Gods” underperformed at the box office last weekend. Early tracking for “Dungeons & Dragons: Honor Among Thieves” doesn’t look much better.

Meanwhile, Disney’s two biggest properties, Marvel and Star Wars, both seem to have hit an inflection point. Marvel fired longtime president of physical and postproduction Victoria Alonso this past week,...