The swampy jungle hides more than just monsters.
Long ago, the Bilefen was once home to humanity’s forebears, the Nephalem. As the years went by, humans slowly replaced the Nephalems and established their settlements there. Eventually, the swampy wasteland was overrun by a plague affecting the area’s humans and beasts.
Throughout Bilefen are ancient abandoned temples where the Nephalem resided; the same temples serve as Hidden Lairs where you can farm Normal Gems, Random Gear, and Gold.
Start running through each Hidden Lair location within the zone as soon as the “A Hidden Lair has opened in this zone” flashes across your screen. You only have 10 minutes to find the Hidden Lair and enter it. Otherwise, the Hidden Lair will despawn and repawn in one of the other Hidden Lair locations in the same zone.
Looking for the next Hidden Lair will also be challenging because Hidden Lairs open randomly. Hidden Lair spawns do not have a spawning pattern, which means you have to run around the entire zone to find the open Hidden Lair. You can make this process easier by partying with other players and splitting up across Bilefen to find the open Hidden Lair faster.
Hidden Lair runs are very similar to Elder Rift runs. Hidden Lair dungeons will feature the main objective that requires players to slay the Lair Guardian along with some other minor objectives, like killing groups of monsters in the dungeon.
Unlike Elder Rift dungeon runs, however, Hidden Lair runs do not have a time limit, and all you need to do to progress is kill the Lair Guardian. You do not have to do anything specific to find the Lair Guardian, as this boss is already pre-spawned in the dungeon as soon as you enter the Hidden Lair.
Completing minor objectives will reward you with a large chest full of rewards like Gear or random quality, Normal Gems, and Gold. Defeating the Lair Guardian will give you the same rewards. There’s a healthy amount of XP from clearing Hidden Lairs.
Lastly, some Hidden Lair dungeons will sometimes feature a second floor that you can access via a red portal after defeating the first Lair Guardian. The second floor works the same way as the first one; the Lair Guardian might be identical.
Bilefen’s land area is much smaller than any other zone in Diablo Immortal. But the smaller land area does not help speed up your Hidden Lair search.
Bilefen’s layout does not allow you to cross the map from the Abandoned Village (top half of the map) and Crimsonblade Haven (bottom half of the map) on foot, which means that whenever a Hidden Lair shows up on the other side of the map, you need to use the teleporter or run around the map to find the Hidden Lair.
Fortunately, since Bilefen’s Hidden Lairs are former Nephalem settlements, most of them can be found next to each other at the Abandoned Village. The rest of the Hidden Lairs are found in Crimsonblade.
Finding active Hidden Lairs in Bilefen is easy, thanks to the zone’s use of abandoned settlements as Hidden Lair entrances. The old Nephalem settlements are grouped close to one another, making it easy to jump from one spot to the next in search of the active Hidden Lair.
Of course, make sure you are around or at the recommended Level for this zone before you try to go on Hidden Lair runs, as there is a massive jump in monster difficulty compared to Dark Wood or Shassar Sea. Grind for XP at Tomb of Fahir or upgrade your Gear first to ensure you can survive the swamps of Bilefen.