I'm combining two separate problems and causing more confusion. That last post I rushed and didn't proofread what I'd said. The following is what I've been taught.
On a lost engine landing and your option is a rough field or just rough terrain, land with the gear up. Otherwise, the gear will dig into terrain, be it a plowed field, very rough surface with pits, etc.
If you have gear stuck in retracted position and no means to force them down, land on the smoothest surface possible. Obviously, a runway. Only if you're stable and landing is assured well beyond the threshold, shut down the engine. There was a video a while back (posted here, I think?) showing a twin landing with gear up and shutting down both engines before he flared. I've been taught to do the same in a single engine but it's a last minute action, if at all. Fly the airplane, first.
But should you land gear up by accident, don't attempt to pull up again and go around. The damage has been done by the prop strike and the engine and prop are unstable to continue running.
Again, this is what I've been taught. I freely admit not everything I've been taught is perfect. The broader base of experience is on the younger side. I'll have to read more about various scenarios and what's most recommended.