In the Monopoly board game, purchasing properties and building houses and hotels on them is a key strategy for increasing your wealth and ultimately winning the game. Buying houses in Monopoly allows you to charge other players rent when they land on your properties, increasing your income and giving you an advantage over your opponents.
To buy a house in Monopoly, you must first own all of the properties in a color group. Once you have a monopoly on a color group, you can start buying houses by paying the bank the amount indicated on the property card. The cost of houses increases as you buy more of them on each property. For example, the first house you buy on a property costs $500, the second house costs $1,000, and so on.