I don't know if the droid is CGI or real, but I tried to replicate a possible way to make it. It's basically the same trick they used with the landspeeder in Ep.IV:

And a video:

Wow! It looks great!

Ha that's very clever! But I would guess it's all cgi.

Judging that there's no dust trail behind it, I would also venture to guess that it's all CGI as well. Hopefully this won't be the case all the time, maybe they'll use a practical version for less difficult shots.

No dust doesn't mean its not a practical effect, after all a smooth surface doesn't "Fling" dirt in the air as there is very little for the dirt to get hooked on. the more telling issues here are the lack of sand covering the ball, and lack of a packed trail on the ground, if you've ever rolled a ball on the beach there is always a clear smoothed path left behind and that's from a 12oz ball not a 200lb machine!

Your solution is convincing.

However, I fear it is all cgi.

And what I fear most about #7 is that someone may start singing...

Well even if it's CGI I can't really complain about it. When I first saw the trailer in cinema I thought it looked great and everything looked like scenes from the original films (revised of course in the 89. Special edition). Except the forest scene with mr cross guard sith which looked a much like CGI.

good,Hopefully this won't be the case all the time, maybe they'll use a practical version for less difficult shots

Edited December 12, 201410 yr by gouldtwin

So I guess BB-8 will be practical at least some of the time!

“And when they were demonstrating how they did this thing [bB-8], live on set — because it’s not CGI, that’s a live prop — I was just amazed. They let me play around with it. I was running it all around at the creature shop up in Pinewood. I’m telling you, it’s an absolute delight. And not having thought that I’d ever go back there, to go back into that world, is just – I get the chills. It’s just so much fun.”

-Mark Hamill

I too read it was not CGI.

Mark Hamill, when he was asked if he would join the cast of EPVII, made it a specific prerequisite that they use real props, real sets, models etc. and only resort to cgi where there's no other way to do it. I guess it was a good thing that JJ Abrams wanted to go that route anyway. So...

I had assumed it was a real prop. I mean it would definitely be a stunt to pull off, but I'm guessing they use magnets or something to keep the head on. Seriously makes me wonder how Lego will end up making it when it inevitably ends up in a set.

It could be a prop model, that could have been animated against a blue screen using stop-motion, then edited in.

Thats my best bet on it!