The worlds are filled using the following procedure:

• Assume all progression items are acquired.
• Progression items (non-dungeon) and item locations are shuffled respectively.
• Items are placed one by one. Dungeon items are placed first, followed by all other progression.
  • An item is placed at the next random location where the item is allowed, and where the player can reach it with their remaining progression according to the logic.
  • An item can only be placed cross world if the owning player can reach the same location in their world with their current progression including the item to be placed.

Some bias is applied based on game mode. For multiworld Morph Balls are placed within the last 20% of the pool, and Moon Pearls within the last 40% (which makes them show up earlier).

For singleworld, first sphere locations in Link to the Past are weighted down significantly, and Green, and Pink Brinstar are weighted down slightly.