Property is too inexpensive. In the normal game, it is always a good strategy to purchase property because even if it is not part of a monopoly that one owns, it can be traded for something more useful or mortgaged if not. As a result of this rule, players usually put property up for auction unless they really want it. This rule makes the game much more challenging, since players actually must think about what they are willing to buy and when to start an auction. He or she may only make trades with another player in Jail or any player at Just Visiting.
Good lawyers are expensive.
Makes jail a punishment rather than a safe haven. Whenever a player lands on an unpurchased property, any other player can immediately start an auction for that property by bidding twice the normal purchase price. Balances bad dice rolls by allowing players who are willing to pay extra for particular properties to have a chance at them. If it lands on any owned property, the owner pays the bank the amount that would normally be charged in rent. Removes the annoying requirement of constantly have to watch where other players land.