Roblox plays on a full 3D world created by players run entirely by physics. Players create an avatar to explore other user's creations. The game is designed as an amusement park, and each world the players create is like an attraction. The players have complete control over what their world can be like and give goals for players to complete.
The most popular types of games made include 3D platformer-like obstacle courses (nicknamed Obbys, which stands for Obstacle Course), battle maps using physics based weapons, tycoons which use scripts that allow RPG-like progression, and simple hang-outs where users can chat and explore a world. Other types include racing games with full vehicles, puzzle games, and physics demonstrations.
Each game is created by a player inside a Place. Every user has at least one Place to create whatever they want. By subscribing to a paid subscription, they can have from 10 to 100 Places. Using the Roblox editor, users can use LEGO-like bricks to create worlds or objects, and create scripts to create game rules or player abilities. To get users to come to their place, the player can advertise their Places in the Roblox website by using Robux.
The game is composed of one currency, Robux. The robux is the currency for paying players and is what most of the game's items use. Paying Builder's Club members get an allowance of robux each day, the amount depending on their subscription.