Bally : Variety

Variety

The magic lines on this game were the three left columns of numbers on the bingo card. Each column could be shifted up/down one position. When shifting down, the number on the bottom reappeared on the top and vice-versa. The lines could be shifted before shooting the 4th or the 5th ball, depending features lit on the backglass. Unfortunately, if before 5th ws lit, the game would not score any credits after shooting the 4th ball, but would wait until after the 5th ball was shot. This prevented you from collecting a 3-in-line score after shooting the fourth ball, then rearranging the numbers to go for 5-in-line score on the 5th ball. This limitation wasn't so bad in these initial games with moving numbers, but it becomes much more serious with games that have colored lines that score separately.

This ability to move numbers made it easier to get at least a 3-in-line score, so the player was paid more frequently, which led to more play on the game.

Side 2 of the game flyer has pictures of how magic lines work.

magic lines games

The numbers on the bingo card were on strips that could be moved one position by turning knobs/pushing buttons on the foot rail.

Usually, the numbered strips were the vertical columns of the card, and they could be shifted up/down one position. When a column was shifted up, the top number "wrapped" and became the bottom number. The bottom number wrapped to the top when shifting down.

bally:miss_america introduced horizontally shifting lines that used two 5x5 cards next to each other. A number could be slid from one card to the other.