In a recent clarification regarding Borderlands 4, Gearbox revealed that the game incorporates some open-world-like features while adhering to a more traditional gameplay format. CEO Randy Pitchford highlighted the differences from earlier iterations, stating:

“With Borderlands 3, it was more compartmentalized… Borderlands 4 is the most open and free ever.”
Translation: “Con Borderlands 3, era más compartimentalizado… Borderlands 4 es el más abierto y libre de todos.”

Anthony Nicholson, the Senior Project Producer, emphasized that while the game includes elements such as seamless travel and side missions, it will not stray into the complexities often associated with traditional open-world games:

“We did not set out with the intent to create an ‘open world game’ in the traditional use of that term.”
Translation: “No nos propusimos crear un ‘juego de mundo abierto’ en el sentido tradicional de ese término.”

The game appears to be set on a single planet, Kairos, which is described as having a darker tone compared to its predecessor, Pandora.