Valid Words and the Dictionary: What Can You Play?

One of the first questions new players ask is: "Is that a real word?" Scrabble has a specific answer — it depends on the official word list being used. Understanding what counts as valid gives you confidence when playing and helps you challenge words appropriately.

The Official Word Lists

Scrabble doesn't use a standard dictionary. Instead, players agree on one of several official word lists compiled specifically for the game.

North America: TWL (Tournament Word List)

The Official Scrabble Players Dictionary (OSPD) and its tournament counterpart, the Tournament Word List (TWL), are used in North American club and tournament play. The TWL is slightly larger than the OSPD (the OSPD removes some offensive words that remain in the TWL for tournament use).

International: SOWPODS / Collins Scrabble Words

Most of the rest of the world uses Collins Scrabble Words (CSW), informally called SOWPODS. It is a much larger list — combining the TWL with the British dictionary — and contains significantly more valid words, including many British spellings and terms.

Key difference: A word valid in SOWPODS may not be valid in TWL, and vice versa. Always agree on which list you're using before the game starts.

Casual Play

For kitchen-table games, many players simply use a standard dictionary. This is fine for casual play. Just agree on one dictionary and stick to it.

What Counts as a Valid Word?

A word is valid if it appears in the agreed-upon word list, subject to these rules:

Valid:

  • Common words: PLAY, STONE, WATER
  • Less common words: QOPH, ZOEAE, ADIEU
  • Verb forms: PLAYED, PLAYING, PLAYS
  • Plurals: STONES, WATERS
  • Comparatives and superlatives: STONIEST, FASTER
  • Words that look unusual but are in the list: AA, QI, ZA

Not valid:

  • Proper nouns: LONDON, JAMES, SCRABBLE
  • Abbreviations: DR, MR, ST (as abbreviations)
  • Hyphenated words: WELL-KNOWN
  • Words requiring apostrophes: CAN'T, IT'S
  • Foreign words not adopted into English (generally)

Common Misconceptions

"That's not a real word!"

This reaction is common, especially to short obscure words. But "real" in Scrabble means "in the word list" — not "used in everyday speech." Words like:

  • AA (a type of volcanic lava) — valid
  • QI (vital life energy in Chinese philosophy) — valid
  • ZA (informal for pizza) — valid
  • OX — valid, of course
  • EUOI — an exclamation; valid in Collins, not in TWL

If it's in the list, it's a legal play.

Proper nouns

PARIS, MIKE, GOOGLE — none of these are valid, even if everyone knows them. Scrabble only allows common nouns, verbs, adjectives, adverbs, and other word classes — not names or brand names.

Abbreviations and initialisms

DR (for doctor) is not valid. But DOCTOR is. The word must be spelled out.

How to Challenge a Word

If you suspect your opponent played an invalid word:

  1. Challenge before the next player draws tiles — you can't challenge after the next turn begins.
  2. Look the word up in the agreed dictionary or word list (or use a word judge app like Collins Official Scrabble Words Checker or the TWL app).

Results:

  • Word is invalid (challenge succeeds): Remove the tiles, and the player who played the word loses their turn.
  • Word is valid (challenge fails): The word stays. You (the challenger) lose your turn as a penalty.

Because a failed challenge costs you a turn, choose challenges wisely. Only challenge when you're fairly confident the word is wrong, or when the game situation makes the risk worth taking.

Learning New Words

Scrabble is a great vocabulary builder — but not in the traditional sense. Many words valid in Scrabble aren't words you'd use in a sentence; they're vocabulary items recognized by lexicographers as established in print.

The best approach for new players:

  1. Don't try to memorize the dictionary. Start with short, high-frequency words.
  2. Learn the two-letter words first. There are 107 valid two-letter words in TWL. These form the backbone of good play.
  3. Learn Q-without-U words. QI is the most important. QOPH, QAID, QANAT are useful bonuses.
  4. Accept that you'll encounter unfamiliar words. When an opponent plays something you don't know, look it up. Now you know it too.

Word Lists and Apps

Helpful resources for checking and learning words:

  • Collins Official Scrabble Words app — official Collins/SOWPODS checker
  • TWL Checker — for North American tournament words
  • Zyzzyva — the premier word study software used by competitive players
  • Collins Scrabble Words book — the printed official list

A Note on Etiquette

Constant challenges can slow the game and create tension. In casual play, it's friendly to simply agree "let's look it up" rather than making a formal challenge with a turn penalty. Save strict challenge rules for competitive settings.

Knowing the word list is knowing the rules. The more words you know, the more moves you see.