[dqv]

You can jump rope without the rope. I do this because I don't have much space in my garage for a rope to sling around, so I just pretend to hold the handles and skip rope that way.

[lucky_cloud]

Not as fun though. Using the rope adds challenge and builds/reinforces coordination among all four (usually) limbs

[Nimitz14]

Jumping rope also works out the arms a little which you're not gonna get.

[dqv]

I get a pretty good burn by rotating my arms like I'm skipping a real rope. It's good enough for post work out cardio.