Lüshi (simplified Chinese: 律诗; pinyin: lǜshī) refers to a specific form of Classical Chinese poetry verse form. One of the most important poetry forms of classical Chinese poetry, the lüshi refers to an eight-line regulated verse form with lines made up of five, six, or seven characters; thus:
Five-character eight-line regulated verse (wulü): a form of regulated verse with eight lines of five characters each.
Six-character eight-line regulated verse is relatively rare.
Seven-character eight-line regulated verse (qilü): a form of regulated verse with eight lines of seven characters each.
Extended forms (pailü): expansion of the forms listed above with more than eight lines.
All lüshi forms are rhymed on the even lines, with one rhyme being used throughout the poem. Also, and definitionally, the tonal profile of the poem is controlled (that is, "regulated").