DLC Pack 1, "The Master Trials", was released on June 30, 2017 with version 1.3.0 of Breath of the Wild.
How to Get the DLC
You can purchase the DLC for Breath of the Wild from the title screen, or from the System menu (press + then press R until you reach the System menu).
Make sure to save your game and go to the Nintendo Switch Home Screen to download the latest version of Breath of the Wild. You can press + or - while the cursor is on the Breath of the Wild icon in your Home Screen menu, then go to Software Update to get the latest version. DLC Pack 1 is included in version 1.3.0 of the game, which was released on June 30, 2017.
Overview of DLC Pack 1
If you have purchased the DLC and downloaded the latest version of Breath of the Wild, the game will show information about the DLC the next time you go to the title screen of the game. It includes new challenges, a new map mode, and sidequests leading to rare treasures.
From the title screen, you can choose to play in Master Mode. This mode is more difficult than normal mode, and it only allows you to have one save file and one autosave file. These save files are separate from your normal mode save files, so you will not lose your previously saved game if you start a game in Master Mode.
When you load your saved game, several sidequests will be added to your Adventure Log. Press + to go to the pause screen, then press L until you reach the Adventure Log.
Hero's Path Mode
When you have progressed far enough in the game, press - to open your map, then press X to switch to Hero's Path Mode. You will see the path that you have taken thus far. Hero's Path mode can store about 200 hours of gameplay, after which your oldest steps will be erased from the Hero's Path.
In this mode, you can watch an animation of the path that you have taken. Change speed by pressing up or down. Press A to see an animation of the path. Press left or right to manually go back and forth in the path. You can press Y to show and hide the map icons. Zoom in the map with the R control stick. Press B to Exit Hero's Path Mode.
You can use Hero's Mode to look for areas of Hyrule that you haven't explored yet or have never been to.
EX Trial of the Sword
Before you can do the Trial of the Sword, you have to complete The Hero's Sword quest. After you get the Master Sword, the Sword Monk will talk to you the next time you leave Korok Forest. Go to Korok Forest and walk onto the platform where you found the Master Sword. A cut scene will occur. After the cut scene, you can put the Master Sword back into its pedestal to start the Trial of the Sword.
During the trial, you will go through a series of rooms where you have to defeat all of the enemies. You not be able to use the weapons and armor that you have collected, so you have to pick up whatever weapons and shields you can find. You will also be able to find food items as you go through the trial.
EX Strange Mask Rumors
Go to Woodland Stable and read the book there to learn more. Woodland Stable is south of Woodland Tower. The book is on the table inside of the stable.
The book says that the mask is hidden in a tree hollow in a forest that makes people lose their way. This is a reference to the Lost Woods, which you can reach by going north from the stable. For more information on finding and going through the Lost Woods (including the "convenient trick" mentioned in the rumor book), read The Hero's Sword page.
Click the button below see the location of the treasure chest in the Lost Woods.
EX Teleportation Rumors!
Go to South Akkala Stable and read the book there to learn more. South Akkala Stable is just north of Akkala Tower. The book is on the table inside of the stable.
The book says that the medallion is rumored to be beneath a labyrinth in northeast Akkala. To reach the labyrinth, you will need a lot of stamina, so you should upgrade your Stamina Wheel or at least make plenty of stamina-refilling foods.
If you think you have enough stamina, go northeast from South Akkala Stable (see previous paragraph if you're not at the stable already) to reach Akkala Ancient Tech Lab. Go into the lab and go up the stairs, then find the path leading to the roof of the building. Climb the tower that sticks up near the small end of the telescope. From there, look northeast to see the labyrinth. Float there with the Paraglider. This is Lomei Labyrinth Island.
For information on finding the Travel Medallion in the labyrinth, read the Tu Ka'loh Shrine page.
To use the Travel Medallion, go to the Key Items section of your inventory and choose the medallion, then choose Place. A travel gate will appear on the ground at your location. You will be able to see the Travel Medallion on your map and travel there instantly any time. To change the Travel Medallion location, just select it in your inventory again and choose Place. It will move to the new location.
Go to the Outpost Ruins and read the book there to learn more. The Outpost Ruins are just east of the Great Plateau Tower.