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Number: Puzzle #914
Genre: Platform
Author: Maarten
Appeared at: July 31, 2008
I thoroughly enjoyed this puzzle, as it requires unconventional reasoning.

In fact, now that I'm getting the hang of it, I would like to start designing Platform puzzles. However, I have no clue where to start. Is any author willing to share some insights?

Somehow I find it disappointing that no-one has responded. Maybe because it had no replies?

Hi

When I checked this topic there was nothing in it. so you might have still been editing it at that point. Never checked back to it till now.

I liked this idea, but haven't done many of them recently. When I just got into this type I made a bunch and started to play around with empty holes in the ceiling/floor and mismatched ceilings/floors.

As to designing them, I started by just drawing some random bookcases and seeing how they solved and pick up where some of the uniqueness pitfalls lie as they weren't generally unique.
As to building a puzzle, it's easiest to start from the sides. As those chains and posts are instantly fixed. And if the posts or chains don't make it to a certain row you can eliminate places where shelves can go.
Another easily creatable opening is if the chains and posts add up to (n-1), where n is the height, as then the chains all hang from the top and the post all stand on the ground.
When you have a chain hang somewhere in the middle it decreases the amount of shelves that can go somewhere.
Once you have build openings this way, you can start looking where there are invalid loops: when a shelve is supported by a shelve it supports. This can eliminate places where chains and posts can go. If you find such places you should try using those columns for posts and chains.

I'm not sure if it's all clear. I think it's mostly trying to get a feel for it by trying and seeing how what you put in there affects the puzzle. That's why I just started by drawing them and solving to see how it worked out and then just give it a go. Start with a few smaller and easier ones to get a feel for it.

I'll take http://puzzlepicnic.com/puzzle?1792 as an example.

I opted to make a puzzle with all rows to have 4 shelves for this one.
First I fixed the two sides to 1/2 and 1/2. Because all chains and post have to be functional you have shelves on the left and right side in row 1 and row 3. This also made 2 shelve spaces in row 2 to be unreachable so the rest of the second row is shelves.
Now I chose for column 2 to only have one chain and no posts. This means it had to support the shelve in row 2 and nothing else. This chain has to be supported by the shelve in row 1. So this has to extend at least one more to the right. Also the shelve on the left in row 3 has to extend one to the right.
Then in column 5 I placed 0 chains and in column 1 chain. This makes it impossible for the shelve in row 2 to hang from the shelve in row 1. As you can't support the shelve in row 1, if the only chain in column 6 is hanging from it. This means the shelve in row 2 is supported by a post.
Next I chose for column 6 to also have 1 post. This means the shelve in row 3 can't be support in column 6 so must extend to the left. This fills row 3 with 4 shelve spaces and leave the rest of the row empty.
The right shelve in row 3 has to be supported with a post in column 5 as it supports the shelve in row 2 and thus can't hang from it. With that post in place, I made column 5 to only have one post. Thus the post has to be supported by shelves in row 4, which extend one to the left.and 2 to the right.
With the current information most of the puzzle fills itself out. Just have to fix column 3, which coul be 0/2 or 1/1 for a unique and valid puzzle. I figured 1/1 was the nicest option.

I hope this is clear and it helps a bit with how to build these puzzles.

Thank you for your very comprehensive reply. Hopefully, I will soon get some Platform puzzles of my own up here. I will take your remark about trying to build bookcases and then solve them to see what works by heart.