The rules can vary. One option is to allow each player to explain all three words from a card in one minute. When the time is up, another player takes a new card. At the end of the game, the teacher counts who has explained the most words.
Another option is for a pupil to take a card and throw the dice at the same time. The dice will show which word to explain. The word can be explained without time limits to make the game less stressful.
Alternatively, it can be decided beforehand that only nouns/adjectives/verbs are to be explained.