Successfully complete the indicated tasks to unlock secret masks. Note: The secret masks are also displayed downstairs on a wall at the Base Of Operations.
Ghoul mask: Defeat the secret Hunter boss to get the special Ghoul mask. To unlock the secret Hunter boss fight, first go to the following location in West Potomac Park. Interact with the "MB3" laptop found in the sewer tunnel at the SHD mission to activate the map above the laptop. There is also an SHD Tech Cache in this area. After activating the map, an "X" will appear on the map with a crescent moon symbol above it. Go to the "X" location shown on the map. The location is east of the Lincoln Memorial. Shoot the lightbulb hanging from the platform in the reflecting pool to spawn a secret armored Level 35 Hunter boss. Defeat the boss to get the Ghoul mask. Note: This can only be done at night.
Wraith mask: Go to the following location in the far southeast of the map, just to the right of the Safehouse. There will be a memorial wall with lots of veteran names on it. First, shoot the light that is illuminating the names on the wall. Then, face the wall and select the "Salute" emote approximately six times (if anyone else is with you, they may need to salute as well) to spawn a Level 35 Hunter boss. Defeat the boss to get the Wraith mask. Note: This can only be done at night.
Crimson mask: Go to the following location in Downtown East (northeast of the map), next to the Stronghold. Stand in the middle of the courtyard, and enter each of the two open office buildings. There is a laptop you can interact with on the desk in each building. Interact with both computers to spawn a Level 35 Hunter boss in the courtyard. Defeat the boss to get the Crimson mask. Note: This can only be done at night.
Cross, Death, Diamond, and Phantom masks: Go to a park in the East Mall at the following location. Locate the hidden switch next to the coffee machine in The Pavilion Cafe. Activate the switch, then run around the Christmas tree in the middle of the park a few times to spawn three Level 35 Hunter bosses. Defeat all three Hunter bosses to get the Cross, Death, and Diamond masks. There is a fourth Level 35 Hunter boss that spawns just east of the park, at the following location. Defeat this Hunter boss to get the Phantom mask. Note: This can only be done at night.
Demon mask: Go to the following location in Downtown East (northeast of the map), just to the right of the Control Point. Enter the large glass atrium by going down the escalator and wrapping around to some stairs you ascend to reach the area. There will be four small black and white targets in four windows to the west. Shoot them from top to bottom to spawn a Level 35 Hunter boss. Defeat the boss to get the Demon mask. Note: This can be done during the daytime.
Travel to Foggy Bottom (west area of the map). Follow the road directly west of the safe house to find a point-of-interest. Travel up the road and enter the open doorway to find a ladder leading to the sewers underground, at the following location. Enter the sewers and look for a woman in a bunker. Talk to her, and she will send you to a nearby observatory, where you will unlock a bonus mission. Successfully complete this mission to unlock a WW2 uniform. The uniform can be found in the apparel menu, under the full-body outfit option. Note: If you get lost in the observatory, go upstairs and interact with the painting to reveal a secret passage.Easy loot and money
This trick allows you to collect a lot of loot daily that you can either keep (rarely), or sell/deconstruct for parts. As you progress through the story, complete every Control Point. Note: Control Points become harder at Level 30, after finishing the story. As you capture Control Points, you will unlock Supply Rooms, which contain multiple chests. There is one weapon and one piece of gear in every supply room. There are 2-4 Control Points in every region of the map, which you can fast travel to. The Supply Rooms will resupply every 24 hours (real time). Fast travel to as many Supply Rooms as desired and collect the loot. Then, repeat the process after the Supply Rooms resupply in 24 hours.Unlocking and joining clans
To unlock the Clan menu at your base, successfully complete two Theater Settlement main story missions. Then, return to the Theater Settlement and talk to Larson to recruit her. She will then be sent back to your main base at the White House. You can fast travel back to the White House to talk to her, or access the Clan tab from the main menu. The menu unlocks after she has been recruited. To join a clan, access the Clan menu from the main menu. Select "Options", "Search Clans", enter the name of the clan you want to join, and apply. You can get special rewards like items and cosmetics for joining a clan.