What is the correct order of operations for setting up a game (picking battlefield, deciding turn order, choosing champion, etc.)?

Ruling: The setup order is: reveal legends, reveal chosen champions, choose and reveal battleground (method depends on game type), determine first player and turn order, then draw 4 cards and mulligan (up to two cards to bottom of deck, redraw that many).

Sequence:

• Reveal Legends
• Reveal your Chosen Champions
• Choose and reveal battleground (method depends on game type)
• Determine first player and turn order
• Draw 4 and mulligan (up to two cards to the bottom of your deck, redraw that many)

Nuances:

• Battlefield selection method depends on format: BO1 uses random selection, BO3 allows players to choose their battlefield but cannot reuse it in games 2 or 3
• Current rules don't specify how to determine first player in games 2 and 3 of a BO3 match