This is a basic code breaking puzzle. In case you could use a hint, here are a few:
The code itself if a bit of a puzzle as it is obfuscated by the checkered pattern and under the water. You can thank @chemi for the word of the day: obfuscated means to deliberately make more confusing in order to conceal the truth.
The code is written with metal blocks on the roof of the building.
So depending on the orientation, the code can also be read from left to right towards B or away from B.
The proper direction to read the code is as it is seen on the card image, i.e. towards B.
Well if I told you that I think you'd find the puzzle too easy. I've heard people read it as 6-1-5 or 5-1-9 and even 6-4-6. One way you can look at the code is to strip out all the checkered pattern. I think then you'll at least see that the first character is not the same as the last character and there seems to be a gap between the first character and the second two further implying some difference. The keyword here is "character." Does that help?
The first character is not a number, but a letter.
The code is: b 16.
Well the title is Checkered Base and the description is "How well can you count." The building is checkered with metal blocks and their purpose is to make the code difficult to read. The word Base coincides with the counting bit as it is used to indicate a number system.
Counting from 0 to 9 is considered counting in base-10 as there are ten characters/symbols. Base-16 is counting from 0 through to fifteen more characters/symbols: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F.
The code is the name of a numbering system. It also has three characters that correspond to the three draggables.
So the title is Checkered Base, meaning that the code on the roof of the building, b 16, represents base-16. Even without knowing how to count in base-16, you might be able to infer that after counting from 0 through 9, 'A' may represent 10 and 'B' would represent '11.' Thus the draggables need to be pulled out 11-1-6 positions for B to reach the win.
Another possible approach is that given that the draggables pull out thirteen spaces, the code may count higher than 9, so then the 'b' may be easier to deduce.
Finally, if one does happen to guess that the last two characters are 1 and 6, there would only be eleven tries at the first draggable to get lucky with the solution.
