Originally published at: Revisiting NPCs as Story Tags — Errata — Advanced Old School Revival — OSR+
NPCs in OSR+ are treated as global story tags in conjunction with rules in the Game Master’s Guide in order to simplify encounters.
This has worked great in playtesting over the years, but the system did not prescribe how to handle NPCs engaging other NPCs, such as when a BBEG or other narratively important character attempts to harm an NPC on the party (or vice versa). The newly revised and expanded NPCs as Story Tags rules handle these scenarios with NPC clocks and rules of engagement.
Furthermore, we've added a page that outlines clocks vs. hold and those definitions in the system.