Quoted from jackd104:

My wife just had two friends over for a couple days. Wife plays a little, but far from a pinhead. These other lady's - not into pinball whatsoever. These are all in their 40s, 50s, busy working moms, to give you an idea. We were having a few drinks in the playroom. One of the ladies has a competitive streak and challenged the other two to pinball. The three of them played about four 3-player games on different machines and had a blast. Yeah, their scores were laughably bad, but they didn't know that, they were just comparing themselves to each other. And they had a great time. I did nothing special to make it more enticing or encourage them to play (although I have done stuff like that in the past for more organized parties). At any rate, it was just a great example of spontaneous fun. So maybe you don't need to do much but provide the opportunity and people may take it (or may not). This is also why I have a couple other things in the gameroom like darts and Ms Pac-Man/Galaga, tends to give anyone something to do if they don't like pins.

Quoted from wtatumjr:

To set the mood I replace the flippers with turkey drum sticks.