I'll admit this, I appeared on this in 1984. Two days of filming, in a very draughty old aircraft hanger.
The Crystal Maze was a game show, presented by Richard O'Brien for the first 5 series, then Ed Tudor-pole for the final series. Featuring a team of 6 contestants, the contestants ran around 4 zones, performing various time limited tasks in small rooms to collect crystals. The crystals where then swapped at the end of the games for 5 seconds of time in the Crystal Dome. The dome consisted of a lot of gold and silver foil tokens blown around by massive fans. If you collected 100 more gold tokens than silver you won a week long activity holiday. If you failed, you got very embarrassed. (We were embarrassed!)
The games consisted of skill, mental, physical and mystery games, all time limited. The choices for who played what game were made before we entered each zone. Obviously the show was not filmed in real time. In fact, we filmed in very short bursts. After each person ran into the room, the director would shout "CUT" and we'd be pulled out for 15 minutes till they set the game up. They only had two cameras to film with. We ate a lot of danish pastries and drank a lot of coffee.
Some games were designated as automatic lock-in games. If someone played an automatic lock-in game and fails to perform some specific part of the task, or performs some forbidden action (for example touching the floor with any part of your body) then you were locked in at once, even if you had the crystal or were within the time limit. We never knew if a game was an automatic lock-in game or not. Once a player was locked in, the captain could choose whether to buy them out with a crystal, thus losing 5 seconds of time at the end.
It's hard to explain the attraction of the show. Mostly it was Richard O'Brien, and the fact than on TV the games looked a lot easier than in real life. Even now when people watch it they swear and shout at "stupid" contestants. What's worse is it's ideal pub television, and it's repeated a lot on various channels. One of the girls on another floor at work emailed me 2 weeks ago commenting about it, cue blushes.
I stil have my crystal, sitting on my television. I still have my episode on video as well, which doesn't get watched unless someone else asks.