I was wondering if the knowledgeable audience here would know of a precedent for server-side player triggers implementation in C. The codebase I want to add that to is CircleMUD but if the code is in C, I think it would be easy to adapt from other codebases (if such a thing exists, it's likely to contain few circle-specific references).

To clarify, I'm looking for an example of player triggers, such as "when this happens, do this", preferably with variable support etc. I know this is usually something that clients handle but I want to try to offer it server-side.

Thanks in advance!

This isn't too hard. I don't know of any exact examples for player triggers, but in Smaug there's prog triggers in OLC that include variables. More complex than what you want, but might be a good starting point. I figured Circle had something like this too? Maybe not.