Please note that I have two separate Ms. Pac-Man writeups inside of this one. E2 doesn't allow a single person to have two writeups in one node, so I had to combine these.
Ms. Pac-Man (thing)
Ms. Pac-Man was an old arcade game released by Midway way back in 1981. Licensing was later turned over to Namco to avoid legal troubles.
The story
Ms. Pac-Man started out as a conversion kit for Pac-Man. This original version was written by General Computer Corporation, and was called "Crazy Otto". They brought their "Crazy Otto" game to Midway, and Midway quickly purchased the game, after minimal negotiations (this turned out to be one of the shrewdest deals ever in the arcade industry). Midway made a few changes, and then released the game as Ms. Pac-Man.
Namco owns the rights to this game today, Midway turned them over to Namco in a effort to get Namco to continue licensing games to them. This worked for a short while. but then Midway started making more Pac-Man sequels, such as Pac-Man Plus, Jr. Pac-Man, and Baby Pac-Man, and Namco promptly pulled their license agreement.
The Pac-Man arcade series were released in this order, Pac-Man, Ms. Pac-Man, Super Pac-Man, Pac-Man Plus, Baby Pac-Man, Jr. Pac-Man, Pac & Pal, Pac-Land, Pac-Mania, Pac-Man V R, Namco Classic Collection Volume 2, and Ms. Pac-Man/Galaga - Class Of 1981.
There were also a lot of unauthorized sequels to Ms. Pac-Man, they usually took the form of a daughtercard that plugged into the Pac mainboard, that contained the new game (most of the Pac-Man series ran on identical hardware). These titles include Ms. Pac-Mortem, Multi-Pac, Ms. Pac-Man Plus, and Mr. Pac-Man (that is just a few, there were dozens more of them).
The game
Chances are good that you already know how to play this game. But here it is anyway, just in case Ms. Pac-Man simply wasn't available in your country. This is a maze game, and the object is to eat all the dots that are scattered around the maze. Now that would be just a bit easy, so the designers added in four ghosts to hamper your progress through the maze.
Fortunately there is a power pellet in each corner, eating this pellet allows you to turn the table on the ghosts for a short period of time (you can eat them, instead of them eating you). You can eat the ghosts as long as they stay blue, but it is time to run again when they turn back to their regular color.
Basically this game is exactly like Pac-Man, with a few minor differences. The biggest difference is that the mazes change every few levels, the original Pac-Man used the same maze over and over again. The next difference is that the bonus fruits move around (they remained in the same place in the original Pac-Man. The last difference will probably only be noticed by expert players, and that is the movement of the ghosts. The Ms. Pac-Man ghosts do not have patterns to their movement, which makes this game far more difficult for the advanced player.
The Machine
Ms. Pac-Man was available in three distinct cabinets (not including bootleg versions).
The upright version came in the standard Namco/Midway cabinet. This is the same "swoopy" cabinet that Galaxian, Galaga, and Pac-Man came in as well. These featured painted sideart of Ms. Pac-Man and the ghosts, along with some pink accent lines. The last 10,000 or so Ms. Pac-Man machines to roll off the assembly line had sticker sideart instead, it was the same basic scene, but the colors were brighter, and there were a few minor differences in the layout of the graphics. The marquee showed an image of Ms. Pac-Man lounging on her own logo, with a ghost off to the side. The exact colors used on the marquee varied a bit over the production run (as did the paint codes used on the side), so never buy a replacement marquee without examining it first, as it may not match your machine. The control panel and monitor bezel had a single design that covered both of them, that of a blue background with a pink or maroon stripe going around it, with a few game instructions printed upon them (always replace these items together, if you expect their colors to match perfectly).
The mini version came in a smaller woodgrain cabinet, without any sideart. All of its graphics were scaled down versions of the ones used on the upright, except for a graphic of Ms. Pac-Man chasing three ghosts that appeared on the lower part of the control panel.
The cocktail version came in the standard Namco/Midway woodgrain cocktail table. It was minimally adorned with a logo underneath the top glass, and instructions on the control panels.
All versions used the same internal hardware which consisted of a Pac-Man linear power supply, Electrohome open frame monitor, and a Pac-Man mainboard with the Ms. Pac-Man daughtercard installed. All versions also used the same 4-Way leaf switch joystick, which had a very short throw. That joystick is currently out of production, although the replacement one that Namco sells for the Ms. Pac-Man/Galaga - Class Of 1981 feels exactly the same, but it uses microswitches instead of leaf switches.
Where to play
You can play Ms. Pac-Man almost anywhere. It has been widely ported, cloned, and emulated. Chances are good that their is a version available for both your computer, and any home game consoles you may own. You probably won't have to look very far to find the real thing either, as Ms.Pac-Man machines are still very common out in the real world. My local movie theater has one, and my local pizza shop has one of the new ones.
It seems like everybody wants Ms. Pac-Man in their arcade game collection. I personally think it is overpriced. If you must buy one, then get a new one. There are several companies that are still producing these machines in limited numbers. This is an expensive machine, and you might as well pay the extra to get a new one that is going to give you a good twenty years of service, rather than one that is already twenty years old.
Ms. Pac-Man (idea)
Please note that this node is also equally applicable to Pac-Man, Tempest, Donkey Kong, Centipede, Galaga, Asteroids, Joust, and Defender.
Ms. Pac-Man is not an investment
A couple of weeks ago I was selling a Streetfighter II machine to a guy. He looked over my collection, and decided he wanted my Turbo (Sega driving game, very old). He offered to trade me one of his two Ms. Pac-Man machines. I said no, even though his Ms. Pac was worth about $700 and my Turbo is only worth $300 or so.
Ms. Pac-Man is not a wise investment. It is the single most common arcade game on earth. Right now Ms. Pac-Man machines are bringing in nice prices on eBay, and at live arcade auctions. But, they will not do so forever. People are forgetting about the simple laws of supply and demand. The arcade collecting world tends to focus itself about 20 years in the past, those machines are seen as the most desirable. Those are the games that everyone wants. There is a reason behind this. Most serious game collectors are in their early 30's, which would have made them teenagers right around the time that Ms. Pac-Man was really popular. So naturally they want the games they played when they were kids. This creates a great demand for the most popular (read common) games from that era. Driving the value of these machines well above what they would naturally be.
How many Ms. Pac-Man machines are there anyway
No one knows for sure how many Ms. Pac machines are still around, but it is well into the tens of thousands, with more machines being created everyday. "More everyday?" you ask. "How can that be?" It is simple, first they are still finding these games, in warehouses, backrooms, and basements. Six months ago they found a Ms. Pac-Man machine that was still crated up, it had never even been opened. All of these machines then find their way into the collector market. Each one fullfills someone elses demand for the machine. Secondly, people are making more of them by restoring old converted Midway cabinets. Pac-Man, Ms. Pac-Man, Galaga, and Galaxian all came in the same basic cabinet. About 75 percent of these games were converted into other games, many of them are still on the floors of arcades today (in one disguise or another). (I myself have one that is disguised as a Clutch Hitter.) The collectors buy these games, use reproduction artwork and parts, and bam, make yet another Ms. Pac-Man machine. No one is reproducing the original boardsets, but there is doesn't seem to be much of a shortage of those (legal or not, the aftermarket will start making them if there ever becomes a shortage).
Another factor at work here is the new Ms. Pac-Man/Galaga: Class of 81 game that they have recently started making. These are brand new Ms. Pac-Man machines, with Galaga thrown in to boot. Right now these machines have no effect on the value of your Ms. Pac-Man. But, wait 5 years. Soon those tens of thousands of Ms Pac-Man/Galaga machines will come flooding into the collector market as operators sell them off (vastly reducing the value of existing Ms. Pac-Man and Galaga machines).
The big sell off
One day the market will reach full saturation for these machines. That day is already close. Most hardcore collectors already have a Ms. Pac-Man, as do a lot of less serious collectors. One day (probably only a couple years down the road), someone will put just one to many Ms. Pac-Man machines on the market. Prices will begin to drop because everyone will already have a Ms. Pac-Man. Soon people will begin to sell their Ms. Pac-Man machines, simply because it looks like the value is dropping (think stock market crash). (This has already begun with Space Invaders machines).
Eventually, (about 5 years after market saturation has been reached), people will begin to sell off their Ms. Pac-Man machines again. This time it not be because of value, it will be more of the growing up sort of thing (most people tend to quit the video game/pinball/jukebox hobby when they reach their early 50's). By then my generation will be the big arcade collectors. Neo Geos, Mortal Kombats, and House of the Dead machines will be in demand. The Ms. Pac-Man machines will be relegated to second banana, bringing in only a couple hundred dollars at the auctions, with supply always outstripping demand.
What about other games
Other, less common games will continue to grow in value. There will never be enough Major Havoc, Computer Space, or I, Robot machines to meet collectors demands. (That is why I didn't trade my Turbo for a Ms. Pac-Man, in ten years my Turbo will be worth double what it is now, while the value of that Ms. Pac-Man will have dropped by half).
In closing, if you really want a Ms. Pac-Man machine, I would suggest waiting a couple of years. Buy a different game in the meantime. Then in 5 years ask yourself if you still want one. If you do, then go ahead and buy one. It will probably be half the price that they are now anyway.
2005 update
Ms. Pac-Man prices are down to $400 to $500 and are continuing to fall.
2008 update
Ebay history shows that decent machines can now be had in the $300-$400 range.
2012 update
Ms Pac machines holding in the $300 to $400 range. They no longer seem to show up at game auctions, as the sellers would prefer to sell them to the newbie buyer. Bootleg 60 in 1 circuit boards have severely cut into the market for original machines.