Add-a-ball games start a ball counter at the original number of balls given to a player at the start of the game and then award the player additional balls as objectives are met, incrementing the "current ball" count for each one.

Early add-a-ball games had individually lighted numbers on the backglass indicating the current ball count.  These were usually completely separate models from the non-Add-a-ball games (even of the same name), but in later years an Add-A-Ball "Option" was instead built into a single model, allowing use as either an Add-A-Ball game, a replay game, or a novelty play game, depending of what the government rules in effect at the location.

Because some locations even disallowed the display of the replay or add-a-ball totals wheel, some games came with a sticker to cover the replay counter.  Some games would even "hide" the extra ball count in backglass graphics that could not be seen until an additional ball was added.

Gottlieb games can usually award up to 5 additional balls at any one time.  If one or more of these additional balls are awarded, they are all played before the main ball counter decrements.  So you could win up to 5 balls during the play of 5 regular balls, or a total of up to 25 extra balls. Gottlieb called this the "WOW" feature.  For Williams games, the ball counter started at 5 balls and awarded balls could raise the total to as 10 balls at one time.

Alvin Gottlieb created the concept which was then designed by Wayne Neyens.

Alphanumeric display from WMS's 1990 'Funhouse'

Some machines, particularly before the L.E.D. era, used other means of mechanical animation, such as moving parts behind the backglass or lights that illuminated different colored masks to produce the illusion of movement.

Mechanical Animation on Gottlieb's 1966 'Central Park'

Backbox of Hayburners II

Being glass, backglasses are fragile and subject to peeling over time.  They are also more restricted than translites in the type of artwork which can be produced, although their color is generally more brilliant than that of a translite.

Backglass of Toledo

The earliest relative of the modern pinball machines, bagatelles consist of a basic construction of a frame around a playfield.  They have no flippers, bumpers, ramps or other mechanical items normally found on a pinball machine, nor do they contain lights, sounds, or power sources.  They have no playfield glass and, with rare exception, are not coin-operated.

Bagatelles are still being manufactured today, although most modern versions are made from plastic and can be found primarily in toy stores.

The playfields are usually quite bare compared to pinball machines, having no bumpers, ball guides or lights like pinball machines, but because they share many of the same mechanical elements as pinball machines, they are included in the database.

The playfield usually contains only the targets and holes, labeled with possible pitch results such as single, double, out, etc., and sometimes some small jumps and a second level of targets/holes at the back. Some games even mimic the players running around the bases, often with mechanical figures in the backbox running around a baseball diamond.

As balls fall into the playfield holes, the corresponding numbers are lit up on the Bingo card(s) on the backglass. The ball will then stay into that hole until the end of the game. Bingo games normally have 5 balls per game -- to make them distinctive from the one-ball machines made illegal in most areas -- and (similar to normal Bingo) awards can usually be won by getting three to five numbers in a row on one of the Bingo cards, with larger awards for more numbers in a row or more coins deposited to raise the odds. Players can either play off the replays earned or have the owner exchange them for cash or prizes.

Bingo games have their roots in a 16th century Italian lottery game named Beano, later renamed to Bingo. They are a result of the early desire to reward players with money, free games and awards. Early games to accomplish this were single ball games with horse and dog racing themes. The (Federal Government's) Johnson Act of 1950 caused the demise of one-ball horse racing machines because it outlawed and made a federal offense the inter-state shipment of gambling devices, manuals and repair parts except to states where the devices were legal, and many areas had already declared them illegal since they were deemed a game of chance rather than a game of skill. (The addition of flippers on later pinball machines caused them to be considered a game of skill since the player could have much more affect on the resulting score.) Since horse/dog racing games were usually one-ball games, and since most areas declared specifically that "one-ball" games were illegal, the manufacturers could see that further production of those types of games would be impractical and so switched to the five ball Bingo designs.

You may also want to read an article titled PINGAMES AND GAMBLING - An Historical Survey by Russ Jensen for more historical information on Bingo machines and the laws affecting them

Active bumpers, the most common, are round mushroom-shaped targets set into the playfield which forcefully kick the ball away when struck.  Passive bumpers look similar to active bumpers, but do not kick the ball when hit.

Bally once made a unique type of passive bumper, called a Mushroom Bumper which is a post with a disk on top. When the ball approaches the bumper, it lifts the disk as it strikes the post.  The disk is attached to a shaft down the middle of the post, which rises when the disk is lifted, activating a leaf switch which registers the hit.

Active bumpers are called Jet Bumpers by Williams, Thumper Bumpers by Bally and Pop Bumpers by Gottlieb.

A thumper bumper from Bally's 1975 'Freedom'.

Left:Diagram of captive ball setup.   Right: Captive balls and target from Capcom's 1996 'Breakshot'

Captive Ball Spinner from Williams' 1966 'A-Go-Go'.

Conversion kits usually contained a backglass and instruction cards, and sometimes a new wired playfield (that plugged into the old connections) but which reused the electromechanical or solid state controllers, cabinet, cabinet art, coin mechanisms, scoring mechanisms, etc.  Some conversion kits included additional items, such as cabinet side decals, new game roms, manuals and miscellaneous other items.  Some later kits even contained new solid state electronic boards to upgrade the control system.

In kits where only only a backglass and instruction cards were included, the game play and scoring was not changed in any way and the original manufacturer's name was often still on the game, which can lead to confusion regarding the status of similar games and their manufacturer.

Because the controllers were usually reused, conversion kits were designed to convert one specific game into another.

Unlike conversion kits, which were designed to be installed by the owner/operator in the field, converted games were converted at a manufacturer's facilities (and usually not by the original manufacturer) and then sold as "new" games by the new manufacturer.  This process became popular during World War II when a ban ¡ª announced March-26-1942 ¡ª was placed on the manufacture of new pinball machines beginning May-01-1942 and lasting four years until May-1946, when the ban was finally lifted.

Converted games were remanufactured several ways.  Some games were given a new backglass and playfield, while others were given little more than minor playfield changes, such as a retouching of the original playfield art.  Some conversion manufacturers, such as Victory Games, would not even remove the original manufacturer's name from the machine.  Other conversions would go as far as completely stripping the components from the game and rebuilding it with a new theme, possibly rescreening the playfield, and even including new side art, manuals, score cards, etc. in addition to a new backglass.

Owners would often send in their games to be converted, but manufacturers also purchased games on their own to convert and, using additional parts available from stock, resell to a different owner.

A number of new companies were created solely for the purpose of offering pinball machine conversions.  According to the Pinball Collectors Resource (by Robert Hawkins & Donald Mueting), there were only four manufacturers of pinball machines from before the ban that were still producing them when the ban was lifted!

A dot matrix display from Capcom's 1996 'Breakshot'.

Bank of 5 drop targets from Bally's 1975 'Freedom'

In EMs, end-of-stroke switches are used in several places.  For instance, a slingshot score is not activated by the standup switches, but the standup switches activate the kicking coil, which &mdash when fully engaged &mdash hits the end-of-stroke switch which pulses the score relay.  They are also used on pop bumpers and some stepping units.

Many games manufactured just prior to 1947 may have had flippers retrofitted into them by their operators in an attempt to keep their games profitable after new games were released with flippers.  When used for these games, this specialty will designate that the games were manufactured without flippers, even though a particular instance of the game has them.  These retrofit flipper can be found in various locations on the playfields, as operators fit them in wherever there was room and where they did not interfere with existing wiring.

A type of gate from Bally's 1976 'Freedom'. The ball can pass through from the left, but not from the right.

Also a hole in the playfield that gobbles the ball, causing it to drain.  See also Sinkhole.

Horserace games are were an attempt to capitalize on the popular sport of horse racing by using a game that could be claimed to not be gambling because of the interaction of the user in shooting the ball.  These games used a horse racing theme and they allowed a player to shoot a single ball for each game.  The player would try to shoot the ball and cause it to fall into a scoring hole, which caused the player to win that payoff.  These games usually allowed players to enter more than one coin at a time to increase the payoff odds.  The playfields were often divided into the areas of Win, Place and Show with appropriate odds on the holes in that playfield area.

A note about the 'one ball' designation listed above: Some 'one ball' horserace games manufactured after World War II actually contained 5 balls, even though still only 1 ball was used to score.  The additional four balls were first shot by the player into the "Skill Lane".  This was done to allow operators to continue using the games in the areas where "one ball games" were increasingly being classified as gambling devices.

For these 5 ball horserace games, the first four balls shot by the player were stored in a pocket positioned just to the left of the rebound spring at the left edge of the rebound arch at the top of the playfield.  The only skill required to reach this "Skill Lane" was the ability to shoot a ball hard enough to reach the left side of the playfield.  Making all four balls into the "Skill Lane" had no effect on the game play or the payout.  After four balls were in the "Skill Lane", the rebound spring was reset to the normal position to allow the 5th (scoring) ball to properly rebound when shot.  If more than one ball made it onto the playfield and dropped into a scoring hole, the payout was disabled for the extra balls.

A basic, single-pole leaf switch

A microswitch with a lever and formable wire attached.

When used as a specialty indicator in this database, this denotes games that were manufacured as a novelty play only model and which had a separate model number given to it by the manufacturer.  If the game merely had novelty play available as an option, but did not have a separate model designation, then it will instead be marked in the notes.

Coin payout machines were eventually labeled gambling machines and outlawed in most states.  At that time, manufacturers converted to awarding and accepting tokens instead of coins in an attempt to circumvent the gambling laws for several years.

Some games may have multiple playfields, with various methods for the ball to travel between them.  The additional playfields are usually smaller and located either above the main playfield, or below the main playfield and visible through a window of some sort.  (Habitrails under the playfield do not count as additional playfields.)

Some games have a 'split-level' playfield where a portion of the playfield is raised above the main playfield.  This is distinguished from 'multiple' playfields because in a split-level playfield there are no real play areas under the raised portion.

A example of a split-level playfield is Williams' 1980 'Black Knight'.  An example of a multi-level playfield is Stern's 2003 'The Simpsons Pinball Party', which has a small second playfield in the upper left corner of the main playfield.

Several playfield inserts from 'Cirqus Voltaire'

Left: A common standard plunger.   Right: Gun handle plunger from Indiana Jones.