The history of video games is replete with origin stories. Most of them are known only to those who follow gaming. There's one story, however, that the average person on the street is likely to have heard: the idea for Pac-Man came about when designer Toru Iwatani ordered a pizza for lunch, ate a slice, and looked at the pie with one slice missing. He was immediately struck with the idea for the game's main character.
It's a good story. But is it too good to be true?
Here's how Iwatani himself put it in Stephen Kent's Ultimate History of Video Games:
[Toru Iwatani] The actual figure of Pac-Man came about as I was having pizza for lunch. I took one wedge and there it was, the figure of Pac-Man.
Seems pretty definitive, no? Straight from the horse's mouth so to speak.
Here he is again in a 2010 interview for Wired.com
Wired.com: Is that story true, that you thought of the shape of Pac-Man after removing one slice from a pizza?
Iwatani: It's true
So I guess that settles it, right? Case closed. Well - maybe not.
How about this, from a 1986 interview by Susan Lammers:
INTERVIEWER: Is the story about the pizza really true?
IWATANI: Well, it's half true. In Japanese the character for mouth (kuchi) is a square shape. It’s not circular like the pizza, but I decided to round it out. There was the temptation to make the Pac Man shape less simple. While I was designing this game, someone suggested we add eyes. But we eventually discarded that idea because once we added eyes; we would want to add glasses and maybe a moustache. There would just be no end to it.
Or this, from Trstan Donovan's Replay:
[Toru Iwatani] When I imagined what women enjoy, the image of them eating cakes and desserts came to mind so I used ‘eating’ as a keyword. When I was doing research with this keyword I came across the image of a pizza with a slice taken out of it and had that eureka moment. So I based the Pac-Man character design on that shape.
One recent author (I forget which one at the moment) claims that Steven Kent told him in a letter that Iwatani had later said something along the lines of "It would be nice if it were true?"
So is the story true, half-true, or just plain false?
We may never know for sure and Iwatani himself has given different answers at different times.
I actually think the Replay story is intriguing. Perhaps Iwatani did come across the image while doing research then he (or someone at Namco) embellished the story by adding the bit about lunch. Once a story is out there, it's harder to undo it (cherished myths can be hard to give up) - and It DOES make for a much better story.
This is, of course, mere speculation on my part.
 Chris Kohler, Q&A Pac-ManCreator Reflects on 30 Years of Dot-Eating, May 10, 2010; http://www.wired.com/gamelife/2010/05/pac-man-30-years/
 Susan M. Lammers, Programmers at Work; New York, Microsoft Press, 1986 (http://programmersatwork.wordpress.com/toru-iwatani-1986-pacman-designer/)
 Donovan, Tristan (2010-07-13). Replay: The History of Video Games (p. 87). Yellow Ant. Kindle Edition.