Written support material for CPRGs has been with the genre from the beginning, even if it often was less a choice and more due to the technical limitations (not enough disk space for text). Support paragraphs for games like in the Gold Box series from SSI had the same quality of writing as the game itself, but prequel novellas that expanded or introduced the overall story were often much weaker (not that the in-game writing was all that good to begin with). Point in case the prequel novella for Divine Divinity, which is – what I would call – barely readable.
If you read this merely to get the gist of what happened previously to Divine Divinity, then okay, the novella does a reasonable job. But apart from that, it’s just terrible. Ten pages in, and it completely changes the focus of what is happening from the far past to a few years later, still in the past. There’s no indication at the start that the first pages are reminiscences of one of the major characters who lived a few years later. The rest is just a rough (very rough) outline of how the council of the seven defeated the Lord of Chaos and how the Sword of Lies ended in the treasure room under Castle Stormfist.
In general, while I think most writers know when to heed the advice show don’t tell, it’s a rule written exactly for material like this. Too much telling, not enough showing to give the reader a personal frame of reference why he should care for any of those characters nor why the story matters at all. Not that any of those characters gets enough characterization to be anything more than just a plot element shifted to get the reader up to the status quo at the beginning of the game.
Not that reading all this is even essential for playing the game, as you get most of the main informations while playing the game. So, superfluous supporting material badly written. The kind of stuff nobody really needs.