Word Search

Find the listed words hidden in a grid of letters — across, down, and diagonally, forwards or backwards.

What it is

A rectangular grid of letters with a themed word list beside it. Every listed word appears in the grid as a straight line of consecutive letters in one of up to eight directions. The unused cells are filled with decoy letters.

How to play

Scan for a word’s rarest letter — a Q or a Z narrows candidates instantly. Sweep each row and column with the word’s first two letters in mind, then check both diagonals. Circle finds and cross them off the list. In this crate’s harder settings, leftover letters can spell a hidden message once every word is found.

Purpose

The most accessible puzzle in the catalogue — no rules to learn, playable by early readers — and the volume seller of printed collections. Product quality lives in the themed wordlists more than the algorithm, and the crate treats the fill as a craft problem: decoys are drawn from the placed words’ own letter distribution, because a uniform fill makes real words pop out.

History

Invented by Norman E. Gibat, published in the Selenby Digest of Norman, Oklahoma, in March 1968 (Spanish-language sopa de letras by Pedro Ocón de Oro is a contemporaneous independent claim). Teachers spread it; by the 1970s it was a fixture of every puzzle magazine.

This implementation

• Spec knobs: rows, cols, theme/word list, directions (kids mode restricts to left-to-right and top-to-bottom), difficulty.
• Generation: backtracking placement with controlled overlap density; fill letters sampled from the placed words’ distribution; word list and answer key rendered from the same placement, so they cannot disagree.
• Guarantees: every listed word is findable and its occurrences are located by scanning the finished grid (the answer key is drawn from that scan, so key and grid cannot disagree); words the filler accidentally duplicates are counted and reported as ambiguous_words in the metadata.
• Difficulty: grid size, direction set, word length distribution and fill entropy, banded.