From the Introduction:
The Ladder is a rules-lite roleplaying game, perfectly suitable for use with new players, and especially with younger players. This lack of complexity has also seen The Ladder used successfully to run internet roleplaying games. Tasks are resolved with a single roll of a standard six-sided die. There's no addition, subtraction or multiplication required, and there are no numbers used to describe how good characters are at things. But I hope it isn't too simple! Have a look and see ...
Why is it called The Ladder? Good question. The entire task resolution system is designed on a 5-step ladder each rung denoting a level of expertise required to achieve a certain effect. If you are 'good' at driving, then we assume you achieve a task result of 'good' most of the time. Occasionally you will be forced to Step Down your success level (to Poor or Fail) or Step Up (to Expert).