Electro-mechanical games (EM games) are types of arcade games that operate on a combination of some electronic circuitry and mechanical actions from the player to move items contained within the game's cabinet. Some of these were early light gun games using light-sensitive sensors on targets to register hits, while others were simulation games such as driving games, combat flight simulators and sports games. EM games were popular in amusement arcades from the late 1940s up until the 1970s, serving as alternatives to pinball machines, which had been stigmatized as games of chance during that period. EM games lost popularity in the 1970s, as arcade video games had emerged to replace them in addition to newer pinball machines designed as games of skill.