Scrabble Dictionaries Explained: NWL, Collins and OSPD

"Is that a real word?" is probably the most common question asked over a Scrabble board. The honest answer is: it depends which dictionary you're using. There isn't one official Scrabble dictionary. There are several, and they disagree on thousands of words. This guide explains the main ones and which you should use.

The three lists you'll hear about

Older guides mention TWL (Tournament Word List). That was the earlier name for the North American tournament list, which is now NWL.

Why the lists differ

Different regions, different vocabulary

Collins includes British and Commonwealth words that North American lists don't, such as many Scottish, Australian and South African terms. That's why a word like ZO (a type of Himalayan cattle) or CH (a dialect form of "I") is fine in a Collins game but not in North American tournament play.

Different update cycles

Both lists are revised every few years to add new words and remove a few. Additions often reflect modern usage, such as technology terms and borrowed words that have become common in English.

Offensive words

In 2020, NASPA removed a large number of slurs from its tournament word list. The family-oriented OSPD has long excluded offensive words. Collins has different policies. If you play casually, it's worth agreeing in advance that slurs aren't welcome regardless of the list.

How big is the difference in practice?

At the two-letter level, the difference is easy to see. Our Collins-based dictionary contains 128 two-letter words. The North American list has fewer, leaving out Collins words such as CH, EE, KY, NY and ZO. Across all lengths, Collins has tens of thousands more words than NWL.

For most casual games, the differences rarely come up. You'll mostly notice them with short, obscure words: exactly the ones strong players rely on for tight plays.

What dictionary does Wordscramblify use?

Our tools use a word list of about 275,000 words that follows the Collins tournament list. We chose it because it's the most inclusive: if a word is valid in either major list, it's very likely in ours. That's the most useful choice for an unscrambler, because it shows you every possibility.

The trade-off: if you play under North American rules, a small share of words we show may not be accepted. When a play depends on an unusual short word, check it against the list your game uses.

What about Words With Friends?

Words With Friends doesn't use NWL or Collins. It uses its own word list, maintained by the game's publisher. It includes some modern and informal words that traditional lists don't, and excludes others. The app checks words automatically, so you'll find out immediately if a word isn't allowed. See Words With Friends vs Scrabble.

What makes a word valid?

Across all the official lists, similar rules apply:

• Allowed: ordinary words, including plurals, verb forms, comparatives (BIGGER, BIGGEST) and many foreign words that have entered English.
• Not allowed: proper nouns (names of people, places or brands), abbreviations, and words that need a hyphen or apostrophe.

Some surprising things are allowed, such as interjections (HMM, SHH, BRR) and letter names (ESS, ZED, AITCH).

Which should you use at home?

• Playing for fun with family: a good general dictionary or OSPD is fine. Agree on it before you start.
• Practising for North American clubs: use NWL.
• Practising for international or UK clubs: use Collins.
• Just curious what's possible: our unscrambler shows the full Collins-based list.

Related reading

• Two-letter Scrabble words
• How to play Scrabble
• Q words without U