system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] How does BB-8 generate traction?
gpt
?

Are you asking how he moves forwards?

Either anti grav like the speeder in ANH or how the toy BB8s do it - a weight at the 'front' on a gyro that makes sure the weight is always in the direction he wants to move. A sphere with an imbalanced centre of gravity will move to make the weight go to the bottom.

If you can then keep shifting that weight, it will keep moving  forward.

Think of a hampster in a hampster ball.