Having worked with Mr. DeMar, I can also say that he engineered other things to make you feel lucky without being so obvious.

It was only recently discovered that in Robotron:2084 (a video title he designed with Eugene Jarvis), the game's difficulty would ratchet down dramatically if your game started out badly (i.e. you were getting killed over and over before making it out of the first wave).

There were also some clever things Larry put into stuff like pinball match routines. This is the "random" number that would come up at the end and if your last two score digits matched, you won a free game. Cleverly, if you were playing a multiple-player game, the odds of one person winning a free game would suddenly increase - thereby increasing the real-world chances that the rest of the players would insert more money for another round.