In addition to standard rolling (which returns results instantly based on a random number generator), Roll20 also features the ability to roll 3D Dice. When you enable this feature, anytime you perform a roll (including rolls in macros), a real-time 3D physics simulation will be shown to you, and the results of the simulation will be used to determine the results of the dice roll.

Here's a quick video showing an overview of how 3D Dice work in Roll20:

Enabling 3D Dice

By default, 3D Dice are disabled. To enable this feature, go to the My Settings tab in the Sidebar. After the Master Music Volume Level Slider is a series of feature checkboxes, you will find a checkbox allowing you to "Enable 3D Dice."

Note that if your computer doesn't meet the minimum requirements to show 3D Dice (e.g. your browser or graphics card do not support WebGL technology), you will receive a warning message letting you know that it can't be turned on.

After 3D Dice have been enabled, all dice rolls you perform that use the standard d4, d6, d8, d10, d12 and d20 dice will be shown in 3D.

To disable 3D Dice, just uncheck the same checkbox.

Viewing Other Player's Rolls

In addition to your own rolls, if have 3D Dice enabled, any other players who also have the feature enabled will see your rolls in real-time as you perform them, and you will see theirs as well.