ยง12.1. A recap of actions
Actions are impulses to do something, which arise sometimes through typed commands:
>examine tapestry
and sometimes through "try" phrases occurring in other rules:
Before examining the tapestry, try switching the ultraviolet light on.
Every action either succeeds or fails, though failure may not be a bad thing (something better may have happened). Besides any rules applied in the source text, actions are subject to basic realism rules. A general rule ensures that actions are rejected if the actor would need to touch something which is out of reach, or see something which is invisible; and a couple of hundred other built-in rules police individual actions. For instance, if the ACTIONS testing command has been used to switch monitoring on, then:
>unlock cage with watermelon
[unlocking cage with watermelon]
That doesn't seem to fit the lock.
[unlocking cage with watermelon - failed the can't unlock without the correct key rule]
Actions generated by "try" phrases are allowed to run "silently", which means that if nothing out of the way happens and they succeed, then nothing is printed. For instance:
Before examining the tapestry: say "(Switching on the lamp first.)"; silently try switching the ultraviolet light on.
There are many ways to impose extra rules on actions, and we have seen three main kinds: Before rules, intended so that preliminary activities like the one above can happen before the action is tried; Instead rules, which block or divert the intention, or may cause something spectacularly different to happen; and After rules, which allow for unexpected consequences after the action has taken place.