Do you know how to turn a cat into a dog?

How about cat - cOt - DOt - DOG? Simple, yes? OK, how about making a fool wise?

In a Doublets puzzle there are missing words between starting and ending words.

• A missing word differs from the previous word by only one letter.
• Fill-in a missing word by selecting the differing letter and tapping the square where the letter belongs in the missing word.
• The puzzle must be completed from the top down.
• The Hint button reveals the missing letter for a word.
• The Restart button starts the current puzzle over again.
• The New button goes to the next unsolved puzzle.
• The game recognizes only one particular solution to a puzzle even if there are others. If you find a better solution, let the author know!

The Doublets puzzles are contained in Doublets Puzzle Databases (DBs) which are downloaded separately. The Doublets game must be loaded with a Doublets DB before there are any puzzles to solve.

• The unregistered version of Doublets only works with the FREE sample DB, "Doublets Puzzle DB #00", downloaded separately. The sample DB has 10 puzzles to try.
• After you purchase the game you can download "Doublets Puzzle DB #01" for FREE and get 50 more Doublets puzzles!
• Additional Doublets Puzzle DBs, each containing 50 new Doublets puzzles, are available for purchase.

A Doublets Puzzle Database must be loaded into the game and then registered.

• HotSync the DB onto your device.
• Load the DB into the game using the DB/Load menu in the game.
• Register the DB using the DB/Register menu.
• The sample DB, "Doublets Puzzle DB #00", uses the Registration Key 12345.
• The free (with game purchase) DB, "Doublets Puzzle DB #01", uses the same Registration Key as the game. For example, if you receive the Registration Key 55555 when you purchase the Doublets game, then you use that key to register the game (using the Game/Register menu) as well as the Doublets Puzzle DB #01 (using the DB/Register) menu.
• All other DBs come with their own Registration Key.
• Once loaded into the game, a Doublets Puzzle DB is deleted from your device to conserve memory space.