Take a rectangular sheet of paper and make three incisions as shown.
Fold the bottom right part to the left.
Fold the bottom left part to the right.
Fold the bottom edge upward.
Hold the bottom part with a paper clip.
Slightly fold the top right part toward yourself.
Slightly fold the top left part backward.
The Roto Copter is complete! Throw it forward, holding by the bottom part. The Roto Copter will spin to the ground!