The basic goal

You have six tries to guess a hidden five-letter word. Type a word using the on-screen keyboard or your physical keyboard and press Enter to submit it. Only real words from the game dictionary are accepted, so a typo or a made-up word will not use up one of your six guesses.

Reading the colors

After each guess, every letter is colored to tell you how close you were. Suppose the hidden word is CRANE and you guess TRACE:

• Green means the letter is correct and in the right position. R, A and E are all exactly where they belong.
• Yellow means the letter is in the word but in the wrong spot. C appears in CRANE, just not in the fourth position.
• Gray means the letter is not in the word at all. There is no T in CRANE, so you can rule it out entirely.

Duplicate letters are handled carefully. If the hidden word contains one E and your guess contains two, only one of them will be colored. The other stays gray, which is itself a useful clue: it tells you the word does not have a second E.

The computer opponent

This is what makes Headle different from other word games. When you submit your first guess, that word becomes the secret word your opponent has to solve. In return, the opponent's first guess is the word you are trying to find, shown to you as ????? until the game ends.

In other words, you and the computer are solving each other. Your opening guess is not just a probe for information: it is the puzzle you are handing to your opponent. From its second turn onward the opponent plays on, narrowing down your word while you narrow down its own.

Winning, losing and ties

• You win by guessing the hidden word before the opponent guesses yours.
• You lose if the opponent solves your word first, or if you use all six guesses without finding the answer.
• It is a tie if you both solve on the same turn.

Rating and experience

Each finished game adjusts your skill rating using an Elo calculation, the same family of formula used to rate chess players. Beating the opponent raises your rating and losing lowers it, with the size of the change depending on how your rating compares to the opponent's. You also earn experience points for every game you complete, win or lose, so playing regularly is always worth something.

Streaks

When you sign in, Headle tracks your streak. Because the game is a duel, streaks work on the word you successfully defended: if you win or tie, the word you handed your opponent carries over, and playing it again on consecutive days builds the streak. Miss a day and it resets.

A new word every day

A fresh puzzle arrives each day, based on your local time zone rather than a fixed server clock, so the reset happens at midnight where you are. Your progress on the current day is saved automatically, so you can close the tab mid-game and pick up exactly where you left off.