From 1987 on, Bob Lancaster wrote a series of small text-mode games for the MicroLink Personal Computer Users' Group. They were, in chronological order:
While they are all well done, it was always the last one, Crux, that fascinated me most. That is probably because it is, unlike the others, an original game, not the implementation of a well-known concept. It reminds me a bit of Ishido and sometimes a bit of Pipe Dream, but these are just similarities, if the concept of Crux has been used before, I don't know about it.
Crux is called Crux because your game pieces are essentially crosses. The arms have different colors. You have to fit each new cross, which you can rotate, to the already placed ones so that only arms with matching colors touch. This is in itself not very difficult, but your score increases with the number of matches. If you can put a cross on a completely surrounded empty space that's the highest score, and the later in the game, the higher the score will be. Additional points can be won for filling the grid.
As a sidenote, Bob Lancaster put an ML in front of the filenames related to his games, for MicroLink. All the files related to Crux thus were called MLCRUX.*. These two letters were, however, not considered part of the name of the game. In the manual, as well as in an article he later wrote, it is referred to as Crux, not ML Crux. The same goes for all his other games.
