Effacer is a futuristic take on the classic paper and pencil game of hangman. The set-up has the player compete in a series of grammar games against aliens that have "committed crimes against grammar". The goal is to help these aliens learn proper nouns, adjectives, and other parts of speech by correctly guessing letters.
The gameplay involves choosing letters to form words, with correct guesses zapping enemy aliens and incorrect guesses leading to the player's character being hanged. If too many wrong guesses are made, the game is over and the player loses.