Claw machines always look so promising. Pop in a 50 cents and grab the toy or gadget of your choosing. A simple snatch and grab, it should be easy, right? Wrong, of course.

You probably already know that claw machines are rigged. So let Vox.com's Phil Edwards explain exactly how in the above video. For decades, claw machines or cranes have been designed, like most arcade games, to at least make a profit for their owners.

A simple look at a machine manual reveals that the machines can be programmed to only grab at full strength occasionally. In fact, some machines can actually compute how often they need to grab at full strength in order to make a desired profit. Owners can tweak the machine to drop prizes midair. They can also program a machine to ensure it's exceedingly difficult to predict when the claw will have the grip strength required to actually win a prize. That hasn't stopped enthusiasts from trying (and documenting their escapades on YouTube).

The practice of rigging a claw machine to ensure a margin of profit is hardly new, Edwards points out. Claw machines first emerged during the Great Depression and allowed users little opportunity to display their skill at moving the claw. Modern machines might allow for greater maneuverability, but they can still manipulate profit margins.

So, next time you're tempted to go after that adorable teddy bear, know that the odds may not be in your favor.