Saturday 1 October 2011

Puzzle #21: Line of Sight

 Rules for Line of Sight

I am a fan of loop puzzles. When I saw this one, I thought "that's clever". The names it was under were Sight and Site Line, but I thought Line of Sight had a better ring to it. For the Layout I had several ideas which you can see here. The right top one was preferred by people I asked. The left top one is the original layout. If people prefer it differently, I don't mind drawing them differently.
As for the puzzle, it's not too hard. I figured I'd introduce this genre a bit more gently than I normally do. I have this tendency to make really hard first puzzles as it helps me discover what you can do with a genre.

[Edit] First puzzle was not unique. Fixed the left bottom corner.


  1. Rrright, so that is your idea of "not too hard" :)

  2. I didn't write easy. But I thought most deductions were relatively easy. The end in the left bottom is a bit harder with an inner loop deduction. But the right side and left top bit should give you an idea how to work these puzzles.

    It could just be that I've worked on these too much. This puzzle type uses logic that feels harder on first try I think. I'm happy to write a walkthrough for this one, if you want to see what I had intended.

  3. Well, I spend a relatively long time on this one (compared to your other puzzles), but you might be right in that it could be due to lack of practice: the moves seemed mostly elementary after I finally spotted them. The lower left though seemed hard. I mean, this inner loop deduction made me actually do a TnE with a pencil, after staring at it for a while. Maybe I am missing sth simpler there.

  4. I had the same feeling when I solved the ones by Naoki ( where it felt like I was taking a relatively long time on not too difficult deductions.

    I wouldn't say the left bottom is very elementary. It's based on 2 length 3 segments not being able to connect as it would create an inner loop. Which is a long way to normally deduce for an inner loop.