- A player does not wish to immediately buy an unowned property when they land on it.
- Several players wish to buy a number of Houses, Hotels, or Skyscrapers, but the Bank does not have enough to give all players the amount they want.
- A player goes bankrupt to the Bank. When this happens, the Banker immediately auctions ALL of the bankrupted player's properties to the highest bidder (except buildings), and bidding starts at any price.
- A player lands on the Auction space in Monopoly: The Mega Edition and there are unowned properties.
Interestingly, this is one of the most-often overlooked aspects of the game.