Laser Tag

Source: Star Castle
Unlike the Rubik’s cube and Slinky, laser tag–every arcade’s big-ticket item–has roots in the US Army. In the late 1970s, the US Armed Forces wanted to develop a program for soldiers to practice firing at moving targets without the inevitable risks and costs associated with the use of live rounds. To achieve that, they developed the ‘MILES’ system which enabled trainees to use infrared beams on targets for ‘points’. While the system is still used in armies around the world, it’s more commonly known for being a recreational game, particularly for kids.

Source: US Army
Best-Selling Accidental Toy: Mouse Trap

Source: The Super Click
One of the basic tenants of capitalism is that goods and services that increase speed and efficiency will reap much reward in the market. That theory, however, does not apply to the 1963 game known as Mouse Trap. Bringing to life the over-engineered and complex machinations conceived in the mind of cartoonist Rube Goldberg, the game is centered on catching plastic mice in the most inefficient and vexing ways possible.

Source: Crest Web
So in other words, even if your invention might seem strange or unnecessarily difficult, if the name is good (some of Mouse Trap’s inspiring Goldberg cartoons were called “Professor Butts” and “Self-Operating Napkin) and the concept is fun, you could be in for a big profit. Sad news for Goldberg, though: even though his cartoons served as inspiration for “Mouse Trap’s” inventor, Marvin Glass, he received no royalties or portions of licensing fees based on issues with intellectual property laws.