Safecracker

When you begin SafeCracker, one of the first things you will encounter inside the Reception Room is a slider puzzle. It is billed as the most difficult puzzle in the whole game. I don't think so. So many people just hate sliders. Possibly they hate them because they don't understand the technique for solving them. Let's look at some diagrams and see how the technique works.

Normally, sliders are a square grid. They may be 4 x 4 as the one in safecracker is, or 5 x 5 or 6 x 6; it doesn't matter how big they are. They don't have to be square; for a rectangle such as 3 x 4 or 4 x 5, the concept remains the same. Traditionally, the missing piece is the bottom right corner. The correct sequence for such a puzzle is to solve the top row first, the second row next and so on, until there are TWO rows remaining. Then the bottom two rows are solved together as a unit.

Look first at the finished puzzle diagram below. Here, we have numbered each piece sequentially, from left to right, and top to bottom. So, if you see the image of the puzzle either before it is scrambled, or after it is finished, this is the way it looks. The numbers "stick" to the pieces themselves, not the relative positions.

To solve a single row, go from left to right. Place piece one, then two. To finish the row, you must find pieces 3 and 4, and bring them up the side as shown. Then you can slide 3 to the left, and four up. The row is finished, not to be disturbed again. Do the second row the same way. Put piece 5 in place, then piece 6, and arrange 7 and 8 as shown. Finish the row as above. Most people, even those who hate sliders, can get this far on their own. Now for the important part.

The bottom two rows must be solved together, starting at the left. Identify pieces 9 and 13, and place them as shown. Then 13 goes left and down, with 9 following it. Use the same technique with 10 and 14.

The Finished Puzzle
1	2	3	4
5	6	7	8
9	10	11	12
13	14	15

The First Row
1	2		3
?	?	?	4
?	?	?	?
?	?	?	?

The Second Row
1	2	3	4
5	6		7
?	?	?	8
?	?	?	?

Last Two Rows
1	2	3	4
5	6	7	8
	13	9	?
?	?	?	?

Now, here's the bad news.

After you put pieces 10 and 14 in place, pieces 11, 12 and 15 can only be rotated. The programmers apparently forgot the Rule of Parity when they designed this puzzle, and 50% of the time it scrambles in such a way that it is unsolvable! You cannot tell until you reach the final stage whether you can finish or not. If it turns out that you cannot, you must back away, approach the safe again and do the puzzle over. This time, hoping that you hit a solvable one. Anyway, now that you understand sliders, the second time through is a snap. The important thing is to realize that sometimes it is simply impossible, and not to struggle, but do it over. It's not your fault.

Some variations on the original slider plan can make things pretty interesting. There is a slider in TimeLapse that gives people fits. It is a 4 x 4, with an interesting twist. It actually is made up of four 2 x 2 puzzles, which "snap" together and cannot be moved or broken up once they snap together. One has to be careful not to solve the mini-puzzles in the wrong order, (diagonally, for example) or your pieces get trapped. The safest way to avoid this is to do the top row and the leftmost column before completing any of the 2 x 2 sections. Also, the same parity problem rears its head again. Half the time the solution is impossible.

A slightly different approach

The idea suggested for the TimeLapse puzzle works for normal sliders as well. Start with the top row, then the leftmost column, followed by the remainder of the second row, then the rest of the second column from the left, working your way towards the bottom right corner. This method works well, but it can be more difficult to accomplish, only because the pieces can be hard to identify. It's easy if you have a reference image to refer to.

The demon of all sliders is in the exploration phase of Puzz3D 's Orient Express. This one is relatively enormous, the outline is irregular, and there are a few pieces locked into position, so you must work around them. In addition, there are several pieces with blank backgrounds only, hence they all look the same, yet they are unique and the solver is expected to figure out where they go, somehow. If that's not enough, the Finished image is not easily accessible. Guess you're expected to have a photographic memory.

Puzz3D Notre Dame has a good one, a stained-glass window. There is no reference image, but the edge pieces are easily identified, and the picture is not hard to figure out on the fly.

Several websites offer sliders online.
Check out:
http://www.sandlotscience.com/Games/Slider_puzzles.htm
http://www.article19.com/shockwave/slider.htm -- A great one

The Balmoral site is a slider-solver program. Unfortunately, it only handles up to a 3 x 3 grid. You could use it for a 4 x 4 if you solve the top row and the left column, treating the remainder as a 3 x 3; but if you can do that, you can finish the puzzle manually. It's easier than running the solver. Enjoy your sliders now!

This document may only be distributed with the express written permission of the author, Tally Ho
The content of this document may not be altered in any way without the permission of the author.
Any proposed changes or additions to the walkthrough may be submitted to Tally Ho.

Safecracker

Slider Puzzle Help

Spring, 2001

Now, here's the bad news.

A slightly different approach