On the UK Roleplayers forum, Ragr has given the Esoterror Factbook a great 8/10. Ragr says the Factbook “…expands the background wonderfully and provides great advice for developing characters and helping the players to visualise exactly what their job as OV investigators is all about.”
Ragr concludes by saying:
“For me this book was a palpable hit and highly recommended, if not essential, if you’re plunging into the world of Esoterror and want to maximise the experience.”
You can read the full review of the Esoterror Factbook on the UK Roleplayers forum here.