This Star Wars shirt features an image of Darth Vader and one of the Sith Lord's most memorable quotes, You Underestimate The Power Of The Dark Side. Vader delivered this line before his epic Lightsaber battle with Luke Skywalker in the 1983 film Return of the Jedi. This Power of the Dark Side t-shirt may not allow you to project Force lightning, but it will let everyone know that you are a fan of Darth Vader and Star Wars.