Insurmountable Waist Height Fence....оf DOOOOM!
You may be an intergalactic warlord stocked with a hand-held nuclear device and laser eyes, but if you think you can just step over a waist-high picket fence, you've got another thing coming, mister.(c)
Apparently being able to rend the very fabric of space and time with your magic isn't enough to budge an overgrown twig.(c)