Game Passes are a feature that allows place creators to sell abilities or special perks in their game for currency. The Game Pass provides an alternative to selling a VIP Shirt and is easier to create and sell.
Game Passes are free to make by anyone (no Builders Club required). There are two ways to get to the Game Pass creation page. Firstly you could go to your profile page and click "Create a Game Pass" under one of your active places or go to the develop page and click the configuration dropdown button for one of your places and select "Create Game Pass". Once you're on that page, follow the instructions to create your Game Pass.
Once you have created your Game Pass, you might notice that it doesn't show up on your place's page! In order for it to show up, the game pass must be on sale or available for free. You can do this by going to the Game Pass's page, clicking the options button at the top-right, clicking "Configure this Game Pass", enabling selling the item however you want to, and finally clicking "Save Changes."
Scripters can use the PlayerOwnsAsset method of the MarketplaceService to detect if a player has a certain pass. From there, you can grant the player the privileges or special perks that they have purchased.
Here's an example script to get started:
Here's an example for giving effects directly after purchase
In order to buy a Game Pass from a place creator, you must first navigate to their place's page. Scroll down the page and you will see a Game Passes section if the place has them. From there, you can see the icon, name, and description of all passes as well as a convenient "Buy Now" button to the right if the pass is being sold.
Alternatively some developers are now using MarketplaceService in order to facilitate in-game transactions for their players. They do this through the use of the PromptPurchase method, which prompts the given user to buy an item. However, please note that not all developers will implement this.