Games should be used to introduce new materials, reinforce learning through repetition, and strengthen skills like vocabulary. They work best when selected based on student age and ability, use the target language, last 10-15 minutes, involve all students, and have clear rules demonstrated through examples. Games are meant to be an integral part of language teaching, focusing on functional language and targeted vocabulary, rather than only occasional activities. Memory games in particular can reinforce vocabulary through matching cards while being engaging for students of various ages and abilities when played in a structured way with turns.