Arkadium's Codeword

How to play Arkadium's Codeword

• The grid is filled with numbers instead of blank squares.
• Each number stands for one letter, consistently across the whole grid.
• A few letters are given to start you off.
• Type a letter into any square carrying a number and it fills every square with that number.
• A hint system will reveal letters when the deduction stalls.

Frequency

The first thing to do is count. Before writing anything, look at which numbers appear most often. In English, E, T, A, O, I and N dominate, and the most frequent number in a grid is very rarely something exotic.

Patterns

Short entries are where codewords open up. A two letter word has a limited set of possibilities. A three letter word with a repeated outer number is even more constrained.

Look for a number that ends many words. That is your S. Look for a number that appears doubled inside words. That narrows to a handful of letters.

When to use hints

Hints reveal a letter. They are worth spending when you have a corner where the deduction has genuinely closed, and worth avoiding early, because a codeword unravels quickly once three or four letters are fixed and a hint spent at the start skips the part that makes the puzzle work.

Tips and strategy

Opening moves

• Count the number frequencies before writing anything. The most common numbers are the common vowels and the letter T.
• Find the shortest entries and work out what they can be. Two and three letter words carry the most constraint per square.
• A number that appears at the end of several words is almost always S.

Building out

• Every letter you place fills the whole grid at once, so check what your new letters do to entries elsewhere before continuing.
• Doubled numbers inside a word narrow the field sharply. English doubles a small set of letters and almost never doubles the rest.
• If a placement forces an impossible letter combination somewhere else, it is wrong. Undo it immediately rather than hoping.

What not to do

• Guessing a word from its shape without checking that its letters work everywhere else that number appears.
• Spending hints in the first few minutes, before frequency analysis has had a chance to work.
• Ignoring the two letter entries because they look trivial. They are the most informative squares on the board.

For clued puzzles instead, the crossword page has the dailies, and Cryptogram is the sentence length version of the same cipher idea.