In March 1983, the very second Fighting Fantasy gamebook, The Citadel of Chaos, was published in the UK. Having each written one half of the first book, The Warlock of Firetop Mountain, Steve Jackson and Ian Livingstone divided their labours for the next books, and Citadel was Jackson's solo effort; Livingstone's offering, The Forest of Doom, was released the very same day.
The Citadel of Chaos is an unusual gamebook in many ways. There's the original cover art pictured above, for one thing, which was the subject of much criticism for its low quality (it isn't even clear what the monster in the foreground is meant to be, as it doesn't match any of the creatures in the game); it was provided by an artist credited only as 'Emmanuel', who has very few other professional credits to their name and about whom we know practically nothing. It became one of the very few Fighting Fantasy covers to be entirely replaced during the original series' 1982-95 lifespan, with the replacement coming from range stalwart Ian Miller, who also provided the covers for several other entries by Jackson and worked on the range right up until it was cancelled by Puffin Books.
It's also an unusual, possibly unique, book in that even if you roll the lowest possible numbers when calculating your statistics, you still have a very good chance of managing to beat the game, primarily because there is only one mandatory combat in the whole thing, and very few other STAMINA penalties outside of combat or stat checks. It only once uses Jackson's signature tactic of having items or clues with numbers associated with them that allow you to take an option not expressly given by the text, in a relatively simple way; the combination to a lock is written down somewhere and you have to turn to that number section when prompted. That isn't to say it's an easy gamebook to beat by any means -- in particular the Puzzle Boss approach to the final encounter with the master of the Citadel, Balthus Dire is excellently engineered. It's a good challenge that never reaches the hair-tearing levels of frustration some of Jackson's other books could provoke.