Child's Play

An interactive fiction by Stephen Granade (2007) - the Inform 7 source text
Chapter 11 - Noticeability, Which Keeps People from Seeing Things

[A mechanism for marking certain objects as not to be taken by playmates]
A thing can be noticeable by playmates. A thing is normally noticeable by playmates.
Definition: a thing is pickupable:
    if it is not noticeable by playmates then decide no;
    if it is carryable then decide yes;
    decide no.
Definition: a thing is worth noting:
    if it is noticeable by playmates then decide yes;
    decide no.

The source code to Child's Play is licensed under a Creative Commons NonCommercial Sampling Plus 1.0 License.