The Ancestors of the modern pinball game were much like Pachinko machines. They were not upright like Pachinko machines, but they did have many pins and holes in the playfield. Balls came down from the top and scored varing amounts of points depending on which hole they eventually fell into. This is probably how the term pin-ball came about.
The coin-operated industry began in 1931 with the production of Ballyhoo. It was built by Raymond Maloney, who later founded the Bally manufacturing company. It was not untill 1936, however, until the term "pinball" was coined. In 1934, the infamous tilt mechanism was devised. People realized they could manipulate the game to their advantage by shaking it, so manufacturers had to come up with a way to stop the cheating. Supposedly, one of the ideas that did not make it into production was pounding sharp pins or nails onto the side and bottom of the machine (this was quickly rejected on the assumption that players would get so mad that they would really inflict some damage on the machine.) One of the earliest implementations involved a ball on a pedestal that would fall off when the machine was moved around too much. On modern machines, there are two tilt sensors: the standard movement tilt and the slam tilt. Slam tilts are used to detect major abuse (such as slamming your hand into the front of the coin door or dropping the machine) and are just a couple of leaf switches that signal a slam when they touch each other. The movement tilt is detected by a pendulum and bob mechanism that moves around inside a ring. A tilt (or tilt warning) occurs when the metal pendulum rod touches the metal ring. 1947 was the big year. Humpty Dumpty - the first game with flippers - was released by Gottleib. The flippers were not set up as we know them today, however. There were three set of two flippers located at three different spots going up the playfield. They were facing each other, as flippers do today, but the pivot point was at the bottom of the flippers. Iin January 1948, a company called Genco placed the flippers at the bottom of the playfield in their game Triple Action. The configuration was still a little unusual: the flippers were facing outward, not inward. The first game that had the flippers set up as we know and love them today was probably Spot Bowler, a 1950 Gottleib game. If you have not seen one of these older games, you might be surprised at the size of their flippers. They were about the size of two pinballs in length, much like some of the small flippers used in today's games (such as the leftside flipper on The Addams Family). It was not until 1970 that games started using the longer flippers on a regular basis.
One of the darkest days in pinball history came about on January 21, 1942. Pinball was banned in New York City because it was viewed as a game of luck rather than a game of skill (ergo, playing pinball is gambling!). To "Celebrate" the ban, Mayor Fiorello Henry LaGuardia (as in LaGuardia airport) smashed a number of machines in front of a largely supportive crowd. The ban lasted until 1976. Free games (replays, matches, etc.) continue to be illegal in New York City to this day, although the law goes unenforced.
In 1960 the idea of an earnable extra ball first appeared in Gottleib's Flipper. This was done in response to the laws of many areas that made it illegal to award replays.
The first drop targets were introduced in Williams' Vagabond game in 1962. The next major change came in 1975. The first non-relay-based game, called Spirit of 76, was produced by Micro. It marked the beginning of the switch from electromechanical to solid state games. The first widely available solid state game (only 100 Spirit Of 76's were made, mostly due to an unattractive playfield) was Freedom from Bally in 1976. Many games in the1976-1979 period were made in two versions (both solid state and electromechanical) as manufacturers refined the process of moving to the new technology. In 1979, the first talking game was produced: Gorgar, from Williams. In the early 1980's, many games started using magnets to let their player try and save the ball (called magna-save by Williams). Black Knight and Jungle Lord are two good examples of this. The next major revolution in pinball was not until 1991, when Data East came out with the first dot-matrix display in their game Checkpoint. Starting around 1992, all games from all manufacturers have employed a dot-matrix display.
So where are we today? Pinball has come a long way in the last six years or so, particularly in complexity. It will also continue to advance with the technology. One important advent in pinball history is the introduction of pinball simulations on home computers. While there are some good SIMULATIONS out there nothing beats the feel of having a full sized machine in front of you with real bells, buzzers and flippers.
In summary, pinball is a great game with a glorious past. As far as the future goes, who knows what revelations and changes it will bring. I can tell you this much, it won't be long after the first colonists settle on the planet Mars that the first pinball machine will arrive to challenge, frustrate and entertain them.