Depends. EMs and SS are 5 ball games. DMD are 3 ball.

I tend to think there's a divide in the SS era though - while FH is a WPC game, its not DMD and seems right with three balls. The five ball rules don't feel right to me.

Games up to the early 1980's I found were mostly five ball, but starting to appear in three ball versions. I recall a Firepower on site somewhere in the early days of its release on three ball and nearly causing a riot..... I'm thinking through the 80's there was a choice made by operators and a progression to 3 ball by the end of the 80's. I recall noting that older SS games would get set to five ball when they were no longer the new kid on the block, to attract the players with the additional ball count.