The target is crushed when the user falls on top of it. If it misses, the user is hurt instead.
The user leaps into the air and comes crashing down onto the target, or perhaps just rolls or flops down on top of it. It lands with the force of a plummeting stone, badly crushing the target if it hits, but injuring itself instead if it strikes the hard ground instead of its foe.
If this move misses, is blocked by Protect or Detect, or has no effect, the user takes damage equal to half its max HP, rounded down.