It can help you form two words in one play by making an already-played word plural. The "S" may be the most versatile tile in Scrabble. This can't always be avoided, but if you can make a word in some other part of the board, even if it doesn't score quite as much, it might be a better move. When you play adjacent to these squares, it makes it easier for your opponent to use them. Don't give the opponent an easy double word or triple word score.If you are caught with a high scoring letter in your rack at the end of the game, it counts against you. Late in the game, it might be best to just play them. Letters like "Q" and "X" are best used in combination with one of the special squares to get the maximum value out of them. Don't always play high scoring letters just because you can.If two players tie, the person with the fewest points subtracted from their score wins. At the end of the game, all tiles in a player's rack are subtracted from their score and the highest score wins.This means any special scoring squares are counted for both words. If two or more words are formed on a single turn, each word is scored individually.The 50 bonus points do not count toward double and triple word scores. A player using all seven letters in their rack gains a bonus 50 points to their score after all other special squares are counted.Double letter and triple letter squares are counted first to obtain the initial word score, and then any double word score or triple word score squares are counted.The pink square in the middle of the board used to start the game is a double word score. This remains true even if a blank tile covers the double word score or triple word score square. The pink double word squares double the entire word value and the red triple word scores triple the entire word value.If a blank tile is played on either of these special squares, it still contributes nothing toward the total word score because a blank tile has a score of zero. The light blue double letter square doubles the point value for the tile played on it, and the blue triple letter square triples the value for the tile.
Special squares (double letter score, triple letter score, and so forth) only count the first time a letter is played on them.