The Demon Pits of Caeldo was written by Kerry Lloyd and published by Gamelords in 1983 as 28-page book.[1]
Shannon Appelcline explained that the company Phoenix Games "was where new RPG author Kerry Lloyd got his first book published, a 'generic fantasy' adventure called The Mines of Keridav (1979). He had a sequel, The Demon Pits of Caeldo, ready to go but Phoenix Games disappeared before the latter could be published."[2]: 129 Appecline notes that Lloyd founded his own company Gamelords soon after, and that by 1983 "Notable books in these last years included: Haven: Secrets of the Labyrinth (1983), the long-delayed second supplement detailing the massive city; The Mines of Keridav (1983), a Thieves' Guild reprint of Kerry Lloyd's original publication; and The Demon Pits of Caeldo (1983), the never-printed adventure promised by Phoenix four years previous."[2]: 131