The ability to wager money is first introduced in Grand Theft Auto: Vice City, when the player must pay entrance fees for Vice Street Racer events, with a set limit on how much they can bet, and perform well enough in the races to break even. Now get out there and work through the new casino missions. Gambling is the wagering of money on an event with uncertain outcomes with intent to win additional money. However you decide to kit out your GTA Online casino Penthouse, you'll be living the high life in opulent surroundings. You can also kit out your suite with a variety of artwork pieces, which are accessed through the Interaction Menu > Penthouse Management > Place Decorations then choosing a room and the piece(s) you wish to purchase with chips before selecting a placement for them. Here, you can acquire casino chips in the same way you would from the Cashier (with the same restrictions), host a party for $20,000, order the Valet to deliver one of your vehicles from the garage, request a free bottle of champagne to add to your inventory, call in the Cleaning Service if your Penthouse needs a spruce up, order a limousine to take you to a set destination, or have a helicopter you own delivered to the rooftop helipad.
The other key feature of owning a GTA Online casino Penthouse is being able to access Phone Services, available by picking up the telephone marked by an i on the minimap near the lift.
