Lù Shízhōng 路時中, zì Dāngkě 當可, was a Northern-Sòng Daoist active in the second quarter of the twelfth century, founder of the Yùtáng dàfǎ 玉堂大法 (“Great Method of the Jade Hall”) tradition. He is widely cited in Southern-Sòng liturgical literature under the honorific Lù zhēnguān 路真官 (“True Official Lù”; e.g., [[KR5c1307|DZ 1307 Hǎiqióng Bózhēnrén yǔlù 海瓊白真人語錄]] 2.7b, 8b). According to an anecdote in the Yíjiān zhì 夷堅志 (“Bǐngzhì” 13.12.479), based on the account of a former schoolmate, Lù came from Shàngshuǐ 商水 county in Chénzhōu 陳州 (modern Hénán), where his father (or, in another version, a great-uncle) Lù Guān 路紳 served as county magistrate. He was seventeen suì in the Zhènghé era (1111–1117); a second anecdote in the same source (“Dīngzhì” 18.1.684) suggests he probably acquired his methods in Shǔ 蜀 (Sìchuān). Datable episodes in his adult life all fall in the period 1125–1130 and show him active from Xúzhōu 徐州 in the north to Jīnlíng 金陵 (Nánjīng) in the south, performing large-scale ceremonies for members of the official class — including a Huánglù jiào 黃籙醮 in 1125 in Jīnlíng for the repose of the soul of a former vice-president of the Board of Finance, Cài Jūhòu 蔡居厚.
The Yùtáng dàfǎ tradition centres on a 1120 vision in which Zhào Shēng 趙昇, a disciple of Zhāng Dàolíng 張道陵, descended into Lù’s bedchamber and revealed to him a bìshū 祕書 buried in the ground at Mount Máo 茅山. Lù later (during a posting as tóngshǒu 通守 of Jīnlíng) excavated the scroll, arranged it in twenty-four sections, and in 1126, while staying at Pílíng 毗陵 (Jiāngsū), transmitted it to the world. The “model sayings” (géyán 格言) interspersed in the ritual handbook were, according to its second colophon, revealed orally one by one in the first half of 1107 by the Dàjiàozhǔ tiānjūn 大教主天君 (Master of the Great Teaching), in a baby-like voice audible only to Lù and his disciple Zhái Rǔwén 翟汝文 (1076–1141). The complete corpus was finally written down in 1158, the year of the present recension.
The principal monument of the school is [[KR5a0221|DZ 220 Wúshàng xuányuán sāntiān yùtáng dàfǎ]]; the related meditative text [[KR5a0222|DZ 221 Wúshàng sāntiān yùtáng zhèngzōng gāobēn nèijǐng yùshū]] is essentially the inner-practice manual on the same revelation. The school is presented internally as the inner secret (nèibì 內祕) of the Tiānxīn zhèngfǎ 天心正法 movement, of which it is treated as the meditative core (the Tiānxīn zhèngfǎ itself representing the “outer” exorcistic practice).