&gt; Is there a room which is so fiendishly complicated that wherever you hold the match there are some dark spots in the room? Nobody knows the answer...<p>Yes, if you allow walls to be curved:<p><a href="http:&#x2F;&#x2F;blog.zacharyabel.com&#x2F;tag&#x2F;unilluminable-rooms&#x2F;" rel="nofollow">http:&#x2F;&#x2F;blog.zacharyabel.com&#x2F;tag&#x2F;unilluminable-rooms&#x2F;</a>