Diablo 4 quickly introduces players to the main villain of the game, Lilith. After a fight with her followers, players will spend the next sections of the game trying to find and stop her before she can enact her plans for Sanctuary.
Diablo 4 also offers a large open world full of side content to do, which players can use to power up their characters to prepare them for the main story. Even more of this side content is opened after you beat the main campaign, making it one of your top priorities.
How Many Acts Are There?
Diablo 4 has a total of 6 main acts, along with a prologue and epilogue. The prologue contains the first few missions of the game until you reach the main city of Kyovashad. From there, the next three acts of the game are available. After completing the first three, the next three acts will be completed in order, as the game ramps up to its conclusion.
The first three acts take about two and a half hours to complete, each containing multiple main missions to complete. The fourth act is incredibly short and is mostly used to set up the more intense later acts of the game. The final two acts are the peak of the game action of story events and take closer to four hours each to complete. The epilogue is only a few more missions after the main story, mostly used to wrap up the story and some characters you've met along the way.
Best Act Order
Upon reaching Kyovashad, you'll gain access to the first three acts of the game, all of which will be marked on your map. Each of these acts will take you to different sections of the map, helping you explore the world you're defending from Lilith. These acts can be completed in any order you'd like, as the stories don't continue off of each other. Each of these acts will have you following in Lilith's footsteps, trying to figure out what she is doing here in Sanctuary.
All of these acts are important as they set up major characters and plot points that will eventually be comminuted in the later acts. The first act is the easiest to complete as it takes place in the Fractured Peaks. Since you won't have a mount during the first three acts, travel can be a little slow, making Act One ideal for those looking to jump right into the action.