boo needs no unscrambling at all — the three-letter word is already the strongest play its own letters allow, banking 5 points in Scrabble as it stands. In all, 2 valid words come out of this rack, grouped by length below and checked for Words With Friends as well as Scrabble.
boo is the highest-scoring word from boo, worth 5 points in Scrabble. The top 2 of 2 words are shown here, with the full list organized by length below.
Only one three-letter word uses the letters in boo — and it is boo itself. No unscrambling is needed: the word is already playable as written, worth 5 points in Scrabble.
Unscrambling boo produces exactly one two-letter word: bo. It is not one of the common answers — a genuine unscrambler find — and it banks 4 points in Scrabble.
Swap a single tile in boo and you get a different three-letter rack with its own word list. None of these appear in the results above — they share 2 of the 3 letters, not all of them.
boo is in the NWL, the official Scrabble word list for North America, and in the Words With Friends dictionary, so it's playable exactly as it stands and needs no unscrambling.
The 1-point gap between the two totals comes from the tile values themselves: Scrabble and Words With Friends price the same letters differently.
Dictionaries record two senses for boo. Scrabble and Words With Friends score tiles and not meanings, so every sense below is worth the same 5 points on a Scrabble board:
boo is the only three-letter word the same letters produce. No arrangement of the same tiles scores higher in Scrabble, so playing boo unchanged also takes the maximum points these letters offer.
The highest-scoring play from these letters is boo, worth 5 points in Scrabble, and no other word from boo earns more points in Scrabble. Words With Friends prices the same letters differently, so the top of the list changes on a Words With Friends board. Both scores count tile values only and exclude premium squares.
The letters in boo produce 2 valid words in the Scrabble and Words With Friends dictionaries. The word count by length is: 1 three-letter word and 1 two-letter word.