Pinball machines offer endless challenges for those in search of higher and higher scores, but some tables offer an extra objective based on pure luck and a quirk or physics.  Over at MetaFilter, the community is discussing pinball and related lore which has led to JHarris sharing some interesting information about how some pinball tables can identify when the ball has reached an area it should not normally access during standard play and reward the player for their good fortune.  The legendary The Addams Family table features my favorite example of the practice.  Here's how to open the table's Vault under unusual circumstances along with similar tricks for Indiana Jones and Attack From Mars:

I told you that sometimes, due to the nature of pinball, the ball ends up in places where it's not supposed to be.  What's awesome though is that there are machines that recognize when this has happened, and reward you for it.

Addams Family is one.  Ordinarily the Vault, the hole behind the blue wall at the top of the table, cannot be hit while the wall is in place.  That's not to say it's impossible, it's just not going to happen intentionally.  If it does happen, you get a special quote from Gomez/Raul Julia: "Dirty pool, old man.  I like it!"  And the game will immediately open the Vault and allow a ball to be locked towards Multiball.

Indiana Jones: The Pinball Adventure (Williams' table, not Stern's), if a ball falls into the ball lock while it's closed, has a quote from Short Round: "You cheat Dr. Jones" and awards points.

Best of all is Attack From Mars.  In that game, one of the major objectives is to destroy saucers.  You make a saucer available by hitting the red target bank in the top middle of the table.  Then the target bank recedes down into the machine, making the sloped banks behind it available.  Hits to these banks register as "damage" to the saucer.  When enough damage has been done, the amount of which needed increasing as you destroy saucers, the target at the top of the banks lowers, allowing you to hit a hole.  Hitting it destroys the saucers, worth a large score award, lighting an extra ball after two saucers (on normal settings), and getting you one step closer to destroying them all, starting Destroy Mars, and eventually Rule The Universe.  It also raises the blocking target bank, to set up for opening the next saucer.

The saucers are an unusual mode for pinball in that, once started, almost nothing interrupts them.  Saucers are not reset when you lose a ball or start another mode.  Once you open a saucer, it remains available for damage regardless of all other factors, unless the game ends (or Strobe Multiball starts, but even that just pauses it for a little while).  Starting a regular multiball duing a saucer is one of the best things you can do in fact, because saucer hits have a higher chance than average of being drain shots.

The trick is this: during multiball, destroy a saucer, and have a ball up in that area when the target bank goes up, trapping it in there.  Then use another ball to hit the bank, causing, through the workings of Newtonian physics, the trapped ball to shoot up into the hole while the bank is still up.  The game declares DIRTY POOL on the screen (an homage to the Addams Family trick), and destroys the entire next saucer instantly, awarding you all the points for it!  The later saucers take lots of hits, so this is actually a very good technique, if you can manage it, to save yourself a lot of possible drain shots.

Even modern day digital pinball follows some of these conventions.  I've played rounds of Zen Pinball 2 where the ball flips into an area that should be inaccessible only to be showered with bonus points.  One time I even managed to somehow squeeze the ball out of existence with a flipper (which is physically impossible on a real table), granting a nice bonus.  Pinball tables run deeper than most people expect and it's great to read about some of the tricks and secrets that skilled players can access if they take the experience at more than face value.  For more pinball fun, be sure to check out Episode 89 and Episode 95 of the Power Button podcast.