United Kingdom, Oct. 13 -- Borderlands 4 director Randy Pitchford says he's surprised more studios haven't successfully replicated the looter-shooter formula that has made the franchise a global hit.

The Gearbox Software CEO reflected on the 16-year history of Borderlands and feels that few truly understand what makes players love making decisions about loot.

Pitchford told BBC Radio 5 Live's Let's Talk About Tech gaming podcast: "If other developers better understood why gamers love making decisions about loot, we'd have good competitors."

The gaming boss revealed that with Borderlands 4 - which was released last month - the franchise is expected to surpass 100 million units sold, though he remains humble about that milestone.

Pitchf...