How to play: Students take turns saying a letter, without spelling a word. eg
S1 "B" S2 "A" S3 "T". S3 losses because by adding "T" to the list of letters, they spelt the word "bat".

Variations:
1) Make it a team game.
2) Change it to the first team to spell a word wins. The word has to be at least X letters in length.