Word Chains is a ladder of everyday phrases. Each word pairs with the one below it to make a compound word or a phrase people actually say — POST and OFFICE make POST OFFICE, then OFFICE and HOURS make OFFICE HOURS. The top word is given; for every word after it you see only the first letter and how long it is, and you have five lives to get the whole chain out.
Say the chain opens with LOVE and the next word is six letters starting with L. LOVE LETTER is the phrase, so LETTER goes in. Now LETTER has to link downwards too, and the tile after it is three letters starting with B: LETTER BOX. BOX then gives you OFFICE (BOX OFFICE), OFFICE gives you PARTY (OFFICE PARTY), PARTY gives you HAT (PARTY HAT), and HAT gives you TRICK (HAT TRICK). Notice that each word does two jobs — it finishes the phrase above it and starts the one below it — so a word that fits one direction but leaves nothing to say downwards is almost always wrong.
Every word in the middle of the chain has to end one phrase and begin another. LOVE gives you LOVE SONG as readily as LOVE LETTER, but only one of them leads anywhere. When two candidates both fit the word above, look at the first letter of the word below and let it settle the argument.
You always know the first letter and the exact number of tiles, and that pair rules out most of what comes to mind. If the link after TRAIN is seven letters starting with S, STATION fits and SPOTTER does not — count the tiles before you start typing, not after a guess has cost you a life.
The chain is solved top to bottom, but nothing stops you reading the rest of the board first. The first letters further down often reveal where the chain is heading, and knowing that the last word is five letters starting with H can tell you what the word above it must be.
Typos are free — the board refuses anything that isn't a real word without touching your lives — but a plausible real word that happens to be wrong costs one of the five. That makes a considered second choice cheap to think about and expensive to type.
The hint fills in the leftmost letter you're missing, which is worth most on a long word where the first letter alone leaves dozens of options. On a short word it often hands you the answer outright, and you only get one per puzzle.