This is a robotic hand constructed from Lego Minstorms NXT that plays Rock, Paper, Scissors against a human opponent. It was built by my friend and co-worker Morgan van Blarcum, and programmed by me in the summer of 2013.
Here’s a video I made to show off Rocky IV. It’s better than trying to explain it:
View the source code on my Github. The include file is just a library to communicate with the accelerometer used to read the player’s hand position. It’s from the RobotC Driver Suite written by Xander Soldaat at BotBench.com.