okay pretent there is already a few letters: komo
and then person a say's "d"
and them person b, not seeing any word, can either challenge person a which is asking him to tell him a possible word with komod. (komodo). if person a says a correct word, then then challenger loses. (person b)
however, if person b just continues and randomly guesses, let's say u, and it's komou, then person c can say challenge and person b cannot come up with any word so person b loses the round.
then, lets say if person b did get the word, and said 'd', so it's komod, and then person c either has to say 'o' and lose the round, pick another word to continue it (although i don't know any other continuation of komod, or, person c could challenge person b and lose, if person b says komodo
VERY IMPORTANT
if person a say's ba (totally different game)
and person b thinks of bath, or bathroom, and say's 't', then person b loses because he made the word bat.