Nice short video on the design difficulties of making one of the early first person stealth games, Thief:
https://arstechnica.com/gaming/2018/02/war-stories-thief-the-dark-projects-signature-sneaking-almost-didnt-work/
https://arstechnica.com/gaming/2018/02/war-stories-thief-the-dark-projects-signature-sneaking-almost-didnt-work/







