This is the most "open ended" word game on The Problem Site, similar to the Buider Games at Quote Puzzler.
 

Object of the Game

To think of words which match the criteria specified on the game board.
 

Game Play

When the game begins, you will see one row of three tiles. Two of the tiles will be blank, and one will contain a letter. You must think of a word which contains three letters, and includes the letter given, in the position specified. For example, given the following tiles:
 

You could use any of the following words: DIG, DOG, PIG, TUG, or any other three-letter word which has a G as its third letter. To enter the word you selected, type the missing letters using your keyboard. Note that the green highlight will move as you type letters, and it will skip the letters which were provided by the site, since you are not allowed to change those.

If you make mistakes, you can correct them by clicking the letter you need to fix, or by using the arrow keys to move the highlight. Once you are satisfied that you have a real English language word, press Enter on your keyboard to move to the next word.

Each time you press Enter, a new row will appear, and each row will have one letter more than the previous row, and will have more letters filled in. Continue playing each row as you did the first one.

Note that once you start a new row, you cannot edit the previous row!
 

Each time you finish a "board," if you have at least 4 valid words, you move on to the next level.  In each successive level, you have 5 seconds less than the previous level.

If you prefer to play only one level at a time (which is how the game was originally designed) click the options link on the game page, and set it from "Multi-Level" to "No."

Note that multi-level play does not apply to the daily game; in the daily, you receive just one board (which is the same board everyone else gets for the daily), and that is the entire game.

Scoring

The scoring is based on how many rows and boards you complete, with each successive row worth more points than the previous row, as well as how much time you have remaining on the clock. When the game is over, the site will tell you your score (as well as in between levels if playing the multi-level game). 
 

Solutions

Is there always a solution? Yes! As a matter of fact, all of the puzzles were designed so that there were at least ten possible words for each row. The game uses the Enable2K word list (which is commonly used for online word games) modified to remove vulgarities.