If you're looking for descriptions of pinball terms, see The Pinball Dictionary.
History of Pinball:
Pinball first appeared in the early 1930's, in a different form. They were small, cheap, simple games, descended from Bagatelle, where the player would launch the ball up to the top, where it would bounce around in the pins on the playfield, either coming to rest in little "scoring holes" worth points, or falling down to the bottom, where they were worth nothing. "Baby Whiffle", from Automatic Industries, is generally considered to be the first pinball game.
They were practically designed for the great depression. And because they were cheap and simple, they were immensely popular. They also had a very short lifespan - after a few months, new pinball games would come out with new features, and the old ones would be forgotten.
Pinball had problems right from the outset. Another popular coin-operated machine around the time was the "bell slot machine", and there was a lot of suspicion of pinball as being for gambling purposes just like the slots were. The element of chance, which is central to gambling, also played a big part of pinball, and was often used in anti-pinball crusades. It didn't help that some machines were designed almost solely to be used for gambling, and others set up so they could be used that way, if desired.
1933 saw the introduction of electricity to the machines, in the machine "Contact" by Pacific Amusements Co., in the form of a battery. (Incidently, this was the first machine designed by Harry E. Williams, the person whom Williams Manufacturing was named after) The game used solenoids to add momentum to the ball. It wasn't long before the number of electric features required them to be plugged in. Lights, bells, and the famous backglass started appearing in 1934, though the backglass was much, much smaller.
1935 saw the introduction of "Flash", by Rockola. It was designed with a new feature, which offered a way to compensate players with good skill and high scores without crossing into territory that would make it considered a gambling machine. Instead of awarding money, it would give the player a free game. This soon became common on pinball games, though not all of them - there were still plenty designed specifically for gambling.
Even the free game machines usually had features to allow them to be used for gambling purposes. The machine tracked the number of free games, but usually came with what was called the "knock-off switch". By pressing the switch, one of the free games would be cancelled. This switch, coupled with an internal device that counted the number of games cancelled in this manner, made it simple to use the game for gambling - whether obviously, or secretly.
In December of 1936, the first pinball bumper arrived, in the game "Bumper", by Bally. The ball, after being lanuched, would bounce among the bumpers to score points, which were tracked by lights on the backglass, and the player would watch and hope for high scores. The bumpers were usually metal springs that the ball would bounce off of.
Pinball took a break during World War II, with very few games produced. The ones that were produced were simply conversions of existing games, merely re-themed existin games, usually in a war theme. However, during this time was a day considered one of the darkest in the history of pinball. New York City had decided that pinball, being a game of chance instead of a game of skill, decided to ban it as a method of gambling. The Mayor at the time, Fiorello H. LaGuardia (of LaGuardia Airport), "celebrated" this ban by smashing a number of machines in front of a crowd. (This ban was lifted in 1976, though free games on pinball are still illegal, though unenforced)
After World War II, pinball exploded. In 1947, the Gottelib game Humpty Dumpty redefined what a pinball game was with the inclusion of a totall new feature - the flipper, though it was then called the "flipper bumper". The company proclaimed it as "The greatest triumph in pin game history" For the first time, the player could be involved not just with launching a ball, but interacting with the playfield. Flippers were a huge success, and were soon in every pinball game produced. The last game without flippers, "Manhattan", was produced by United in 1948.
In 1948, a totally new type of bumper was introduced. Instead of the simple bumpers that didn't really affect the ball, the "pop bumper" was quickly showing up on all pinball games. It used a mechanism that would react when it was hit by the ball, causing it to launch the ball really fast away from it, and speeding up pinball.
1951 saw the introduction of another new feature, from Gottleib. The "slingshot kicker" (or "kicker rubber") started appearing. Suddenly there was another playfield element besides the bumper that would get the ball moving. This change was not adopted as quickly, and Williams, the last to use this feature, waited for a couple years until it showed up.
In 1960, on their game "Flipper", Gottleib decided to replace the wooden rails around the glass to metal ones. This change was made by all the other manufacturers right afterwards. That wasn't the only thing that was unique about Flipper. Due to the fact that a number of areas had banned pinball games that awared free games, treating that as a form of gambling, Flipper would award the player an extra ball that the player could earn. And around this same time, the traditional method of scoring, lights on the backglass, started being replaced by "reel scoring", mechanical wheels with numbers.
"Vagabond", by Williams, was introduced in 1962. On the machine was a new type of target - the "drop target". There was more action on the playfield, and the player had more to shoot for.
Up until 1964, pinball games had a person-operated method of getting balls ready for play. The balls would sit in a channel below playfield height next to the launch lane. When a player wanted to get the ball ready for play, she would use the "ball lift lever" to raise the ball and put it into the launch lane. That was eliminated at this time by a new mechanical part - the "ball return solenoid". It would automatically send a ball into the launch lane when another ball was needed in play.
In 1976, a radical change started occuring to pinball machines. Micro introduced "Spirit of 76" - and instead of using electromechanical relays, it used solid state electronics throughout the machine. While the game itself was very unattractive and a failure, the change to solid state caught on. The next few games in the industry were created with both electromechanical and solid state internals, eventually they all went to solid state.
Williams introduced another new feature in 1979. "Gorgon" arrived, and amongst the various sounds the game made was something entirely new - speech. The game now talked to the players.
In the 1980's, magnets started being used to affect play. They started off mainly as methods of saving the ball - see "magna-save" in "Black Knight" by Williams for an example. The magnets never became common, but did find a number of uses over the years.
1991 saw a big change. Data East introduced "Checkpoint". And instead of the digital scoring on LEDs, it had a dot-matrix display. This display allowed fancy graphics and animations to be displayed during the game, and was quickly copied by the other pinball manufacturers.
1992, The Addams Family was introduced to the pinball world by Bally. This machine quickly rose to the top of the monthly top 10 list of most popular pinball machines - and stayed there for years. It rapidly broke records for sales and earnings. It sold over 25,000 units in it's first year. In fact, it was so popular, that they reissued the machine in a special "Gold" edition, which was the same game, just with certain details colored gold. Even today, it's one of the best earners, attracting more players than newer machines. Some are calling it the best pinball of all time.
On October 25, 1999, Williams, now WMS Industries, declared that due to ongoing losses, and poor sales, they were discontinuing their pinball division. They had tried to rekindle profit by introducing Pinball 2000 earlier that year, but it had little impact. Their exit was big news, as for a long time they had been the biggest pinball manufacturer, and produced a number of the biggest games. Their exit only left one company to manufacture pinball games, Stern.
Sources:
History of Pinball Machines, http://www.gameroomantiques.com/HistoryPin.htm
The Penny Arcade Website, http://www.pinballhistory.com
Pingames and Gambling, http://www.frii.com/~jwest/pinball/gambling.html
Pinball Dating, http://members.aol.com/rusjensen/dating.htm
A Brief History of Pinball, http://pinballfun.com/hist.html