The Thayer's Quest game system is unlike any other in arcade history. Using advanced laserdisc technology pioneered in Dragon's Lair, and state of the art features like artificial intelligence and speech synthesis, RDI Video Systems has developed a unique arcade experience.
Thayer's Quest promotional material - 1983
Thayer's Quest was an old laserdisc based arcade game. This is a fantasy title, and has unbelievable graphics (hand drawn animations pulled from a laserdisc). You guide young Thayer on a quest through the three kingdoms (the game says there are five, but they gave up after making three of them, and just left it at that). You are supposed to defeat Sorsabal The Twisted at the end of the game.
This game is far different from most laserdisc games. It is not a "tweak" game, it works more like a Choose Your Own Adventure story. It doesn't always tell you all your available options, but you do not have to memorize complex, precisely timed movements like you do in Dragon's Lair. Once you know what to do in a given Thayer's Quest scene then you will be able to do it everytime. To make up for this ease of memorization the programmers decided to make the game automatically deduct a life every so often, to keep the player from being able to play forever on a single quarter (which was a big problem with Dragon's Lair).
At the start of the game you get to input your name, and the game will insert your name into all the appropriate spoken parts. Don't bother trying to use any obscene words as your name, the game will not let you use any of the following names; fart, cunt, piss, shit, crap, turd, damn, pussy, nigger, spic, kike, queer, scrotum, Kotex, penis, tampon, tampax, anus, ass, prick, fag, whore, bitch, bastard, suck, cock, or fuck. The game also blocks multiple phonetic spellings of the above words, and any words that contain them. I can understand the curse words, but why did they feel the need to block "tampon", "tampax", and "Kotex"? Since when is tampon a dirty word (or even worse, brand names of tampons). Luckily for the perverse, there are plenty of other more creative dirty words that the game will happily accept. The only reason I mentioned the curse blocking is because someone actually went to the trouble to hack the game to take out the curse word blocking (Hey, look Beavis, Thayer said "Tampax", that was cool, huh, huh!).
Thayer's Quest was released only as a conversion kit for Dragon's Lair and Space Ace (the early advertisements were misleading, there were no dedicated cabinets made). The kit replaced a lot of the original hardware, and included new side graphics (which consisted of a huge "RDI" logo, they didn't mention the game on the side, because they planned to release a whole line of games on the Thayer's Quest hardware, but those other games were never made).
This game does not have a joystick at all. Instead it uses a keyboard for control (this was the first arcade game ever to have a qwerty keyboard). In an effort to save several dollars per unit, RDI decided to use a membrane style keyboard instead of a more sturdy switch based one. That was a really bad decision, the keyboards on these games do not last, they are easily damaged, and are not of high enough quality to use in an industrial coin-op product. Luckily someone has written a keyboard emulator, that allows you to replace your Thayer's Quest keyboard with a PC one. It takes an entire computer to do this mod, but it is better than having a non-functional laserdisc game because you can't find one of the non-existant replacement keyboards.
Thayer's Quest also used a laser disc player, it could use either the Pioneer PR-7820, or the Pioneer LD-V1000. A converter is available (it is called the "Laser Ace") that allows you to use about a dozen other models as well, that converter is good for most laser disc games, not just Thayer's Quest.
Where to play
Chances are fairly good that you probably don't have a Thayer's Quest cabinet at your local arcade (now-a-days chances are rather good that you don't even have a local arcade). There is an emulator, but it is a complex beast that requires an actual laserdisc player and a Thayer's Quest laserdisc (if you have all that stuff, you might as well build a whole machine). But all hope is not lost, this game has been ported several times (under different names). The first was "Kingdom: The Far Reaches" which was done in 1995, and then it was done again in 1997 under the title "Reaches".
I do not recommend purchasing laserdisc based arcade games for home use. They are very expensive, do not have a lot of replay value, and all die eventually due to laser rot. If you see a nice one for a few hundred dollars, then by all means pick it up, but these things are not a good buy at the current $1200+ prices that they bring now.