Wednesday, 17th July 2024
Puzzles Solved Yesterday: 141


How do I solve a Kwon-Tom Loop puzzle?
Try working through the tutorial, as that will explain the basic rules and show you how a typical puzzle is solved. If you've ever tried a Slitherlink or Loop The Loop puzzle, the rules here are the same. Alternatively if you want a book that explains many of the basic rules and patterns used during a solve, the author of this website has a book available here.
I can't see the puzzles.
Make sure you are using a modern web browser with Javascript enabled. The site has been tested with Internet Explorer, Firefox and Chrome.
How do I interact with the puzzle?
Click between dots to place a line there. Click a line to change it to a cross, and click once more to erase the cross. If you hold down the mouse button and drag across the puzzle, you can draw continuous lines (or crosses).
Sometimes when I click two or more lines appear.
Try clicking more towards the central point between two dots, and be careful not to accidentally drag the mouse too far while the button is down.
Double-clicking is too slow! Can you help?
Yes. If you hold down the 'shift' key while you're clicking, that will have the same effect as if you'd double-clicked. Shift-click makes a gap become a cross, a cross become a line and a line become a gap. You can also use the right-mouse button to achieve the same effect.
Can I do more than just the current puzzle?
If you're a registered user you have access to the entire archive of puzzles on this site. The 'archives' link at the top of the page will allow you to see puzzles which are at least a week old, along with their solutions. The 'home' link gives you access to the current week's worth of puzzles - it's these that are counted for the leaderboard.

If you don't want to register, you won't be able to see the past week's puzzles - the 'current puzzle' link will show you the puzzle from one week ago. In the 'archives' you'll also have access to the past 15 Monday (easy) puzzles, as well as all older solutions and the current 'Beast Of The Month'.

The reason non-registered users can't see today's puzzle is that otherwise they might solve it, then log in and use their solution to get a really quick time for the leaderboard.

What does the 'Fix Position' button do?
This turns all existing lines and crosses green and won't allow them to be changed. You can then try out a move and see what happens, resetting back to the fixed position if it all goes wrong. 'Un-Fix' will turn the green lines and crosses back to black and allow you to change them again. Some people consider this a bit of a 'cheat', but the hardest puzzles can be very difficult to solve without it.
What does the 'Shading' option do?
When 'shading' is on, you can alter the colour of the squares by clicking in the middle of them. Some people prefer to work this way, marking squares that they know are 'inside' the loop in one colour and squares they know are 'outside' the loop in another colour. You still need to draw the lines in to submit your solution, of course. Pushing the shading button will switch shading styles from 'off' (the default), to 'small' where just the number is shaded, to 'large', where more of the square is shaded. If you're logged in, your shading style will be remembered for future puzzles.
Where's the solution to yesterday's puzzle?
The solutions aren't published until a week after the puzzle is first displayed, so check back at a later date.
Could you explain the difficulty levels?
The level of difficulty is displayed next to a puzzle, ranging from 'easy' up to 'very hard'. Easy puzzles tend to require very straightforward logic to solve, so not much 'thinking ahead' is needed. On the other hand, puzzles ranked as 'very hard' often need some in-depth analysis of potential moves to determine the correct solution.

All puzzles larger than a 10x10 are automatically rated as 'big', rather than a specific difficulty level, because they'll take a while to do regardless of how hard they are.

Why are puzzles on a Monday always easy?
Each day of the week has a specific difficulty level and puzzle size assigned to it. Weekdays (Monday to Friday) are always 10x10 puzzles, ranging from easy on the Monday up to very hard on the Friday. Both Saturday's and Sunday's puzzles are always larger than 10x10, and so are rated 'big'.
Is it possible to save more than one position?
No. You have just one 'save slot' that you can use at any time to store the current puzzle state. The link to load your saved position can be found on the home page.
I solved a puzzle in about 20 minutes, but it says I took 26 hours! What's going on?
The time it takes to solve a puzzle is measured from the very first time you see it until the correct solution is submitted. Even if in the meantime you've saved your position, gone off and done other things for a day (maybe even other puzzles), then come back to it. The reason it's done like this is to stop people from obtaining a fast time on difficult puzzles by printing them off, solving them on paper, and then coming back to quickly fill in the solution.
Could there be more than one solution to a puzzle?
Theoretically this shouldn't be possible. All of the puzzles have been designed in such a way that only one possible solution fits the original layout. If you find a puzzle which appears to have more than one way to solve it, try doing both and double-checking that every square has the correct number of lines around it, and that there are no small loops or lines crossing each other. You'll probably find you've made a mistake somewhere along the way. If you remain convinced that you have two solutions, save your position, let me know the details, and I'll investigate further.
Could we have some larger puzzles please?
If you're a registered user, you should see a link to the 'Beast Of The Month' on the home page. This is a 40x30 puzzle which you can either solve in your browser or print off to solve 'offline'.
If I do a puzzle more than once, will my time be recorded?
No. Only the first attempt at solving a puzzle is timed. You're welcome to do puzzles many times, but it won't have any effect on the scoreboard.
I'm really stuck on a puzzle. Can you help?
No. Try fixing your position and experimenting with lines or crosses in various places. For example, try putting a line next to a '1', then follow the consequences of that move as far as you can. If it results in an invalid board position you can reset back to the fixed position and you now know that a cross must go in the space where you tried the line. Often you'll again be left with an indeterminate position, in which case you'll have to reset back to the fixed position and try something else.
Aren't these puzzles just copies of the Japanese 'Slither Link' puzzles?
'Slither Link' was the inspiration for this web site, but none of the puzzles are copied - they've been created specifically for this site. I have no idea how the Japanese ones are designed, so I devised my own methods for making the puzzles. I didn't think it would be right to use the same name for them (and to be honest I don't think 'slither link' is a great name anyway), so I chose one of my own. Kwon-Tom Loop is perhaps a way of phonetically writing 'quantum loop', which may be a play on 'quantum leap'. 'Quantum' can be defined as the smallest discrete quantity of some physical property that a system can possess, which might describe the route the line takes around a solved puzzle. Then again, it might just be an interesting sounding name.
What are some of the technical implementation details for this web-site?
The site is written in PHP and javascript, with a MySQL database holding all the puzzles and player information. The forums are also custom written for the site, partly to avoid potential security issues, and also to allow site-specific functions to be used. The puzzles themselves are designed off-line, and uploaded to the web-site several weeks in advance of "going live".