A message from Ken Williams about fan fiction:
“Have you written a story using the characters from one of Sierra’s games? If so, share it with us! All contributions are welcome!
That said, I do not have the authority to grant anyone the right to create anything using Sierra’s trademarks. Should Sierra ever complain, then this section will have to be removed.
Assuming no one is trying to profit from Sierra’s trademarks (make money off their fiction) – I can’t imagine that they would object. So, HAVE FUN!